I. The Synthesis Of 2,3,3,4-Tetramethylpentane Ii. The Synthesis Of 3,3-Dimethyl-1-Chlorobutane Iii. Miscellaneous

Citation preview

The Pennsylvania State College The Graduate School Department of Chemistry

I. II.


A Thesis by Charles Richardi Enyeart

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy December


g, , 19^1-2


.. .


The author expresses his appreciation to Dr . Frank C. Whitmore, Research Professor of Organic Chemistry, for his deep interest and helpful suggestions during the progress of this work.



Specifications of equipment...............

. v

I. THE SYNTHESIS OP 2,3,3,^-TETRAMETHYLPENTANE Introduction............................................


Historical A. Preparation of the hydrocarbon by a Grignard alkylation...... B. Preparation of the hydrocarbon through the dehydration of methylisopropyl-tbutylcarbinol........................ C. Attempted preparation of the hydrocarbon through the ketone 3,3 ,l|-trimethyl-2pentanone


••••• 9

. .16

Discussion.............................................. 19 Experimental A. Preparation of the hydrocarbon by a Grignard alkylation Preparation of

methyl isopropyl ketone.......29

Preparation of

dimethylisopropylcarbinol..... 31

Preparation of dimethylisopropylcarbinyl chloride...................................... 32 Alkylation of dimethylisopropylcarbinyl’ chloride ..................................... 33 Refractionation and physical constants of the hydrocarbon...................... ......36 B. Preparation of the hydrocarbon through the dehydration of methylisopropyl-tbutylcarbinol Preparation of


Preparation of pentamethylacetone....... . 38 Preparation of methylisopropyl-t-butylcarbinol.....................


(a) Reaction of pentamethylacetone and raethyImagneslum bromide...... 40 (b) MethyImagnesium bromide and 2 ,[|-dimethyl-2-bromo-3**pentanone. 4l Dehydration of methylisopropyl-t-butylcarbinol ^SO]^)...................... 42 Hydrogenation of 2,3>5,^“tetramethyl1-pentene .......


C. Attempted preparation of the hydrocarbon through the ketone 3 >5 trimethyl-2pentanone Preparation of 2,lp-dimethyl-2-bromo3-pentanone............................... 4-6 Hydrolysis of 2,i)-dimethyl-2-bromo-3pentanone.................


Preparation of trimethylisopropyl glycol..............


Preparation of 3 »3,ij.-trimethyl-2pentanone.........

. 30

(a) By the dehydration of tri­ methylisopropyl glycol......... . 50 (b) Attempted-oxidation of methyldiisopropylcarbinol.............. 51 (c) Bromination and attempted re­ arrangement of methyldiisopropylcarbinol. ..... 52 Reaction of 3 *3 ,i|.-trimethyl-2-pentanone in the G-rignard machine................... 53 Summary.........




II. THE SYNTHESIS’OF. 3,3-DIMETHYL-1-CHLOROBUTANE » * Introduction. • Historical...

• • 5o .





Experimental Preparation of t-butylethylene......


Preparation of 3 >5“^imetkyl“l”bromo1:mtane...... 63 Preparation of 3 ,5“^imethyl-1-butanol.......... 65 ’




(.a) By’ the oxidation of 3 *J^-iitietbyl* I-tfcomomagnesiumbutane................ 65 » (b) By the action of ethylene oxide on t-butyImagnesium chloride............. 67

Preparation of 3 »3“(iiriie'fcbyl-l-chlorobutane


(a) By the action of ZnClo-HCl on the alcohol............................... 69 (b) By the action of SOCI2 on the alcohol...... '........................ 70 (1 ) the hydrocarbon.................72 (c) The constants of the chloride......... 73 The reaction of alcohols in pyridine with S0C12*.....


(a) With isoamyl alcohol..................75 (b) With 2-ethylbutanol...................76 (c) With benzyl alcohol... . .............. 77 Summary.............................................78 Bibliography........................................ 95




Experimental Preparation of l,2-dichloro-2-methylpropane........ 83 Reaction of methyImagnesium bromide with 1 ,2-dichloro-2-methylpropane......................


Reaction of ij.,]4.-dimethyl-3“to’omo-2-pentanone with methylmagnesium bromide......................


The action of 10$ KOH in methanol on i).,i|_-dimethyl-3-bromo~2“pentanone .............. 88 The action of 10$ KOH in methanol on 2,ij.-dimethyl-2-bromo-3“pentanone.................. Bibliography.................................









The fractionating columns used in this work were of the total-condensation variable take-off type des­ cribed by Whitmore and Lux (J. Am. Chem% Soc. 5k, ?IA8 (1 9 3 2 ))• CRE I : A I4.5 x 1.1 cm. column packed with 3/32 inch glass helices (about 10 plates). CRE II: An. 85 x 1.3 cm. column packed with l/8 inch glass helices (12-13 plates). C-II • (

: A 100 x 2.2 cm. column packed with l/8 inch glass helices (li|. plates).


: A 38 x 1*0 column packed with 3/&i+ inch steel helices (#Ij-0 wire) (50 plates). The two special purpose columns, C-II and C-IV,

were the property of Mr. N. C.. Cook.






* The synthesis of 2,3,3,lp-tetramethylpentane was -under­ taken not only for the purpose of preparing a sufficient quantity of the hydrocarbon for the accurate determination of its constants, but also to investigate possible methods which could be used for the preparation of twelve gallons of the nonane for the National Bureau of Standards program. Dinerstein (lip) is the only previous worker to report the synthesis of 2 ,3 ,3 ,ip-tetramethylpentane; however, the present work shows that Dinerstein's product was actually 2,2,3,ip-tetramethylpentane.

Hia preparation involved an

alkylation reaction between dimethyl zinc and 2,3,l|.-trimethyl-3-chloropentane. The olefin, 2,3,3,lj.-tetramethyl-l-pentene, has been found by Whitmore and Laughlin (6]p) to be one of the dehy­ dration products of methylisopropyl-t-butylcarbinol.


normal olefin, 3 ,3“C| -ime‘,:;hyl-2-isopropyl-l-butene, is formed in the ratio of 3 parts to 1 part of the rearranged olefin; the other expected olefin, 2 ,2 ,3 ,l|.-tetramethyl-3-pentene is found only in traces.

This method of preparing 2,3,3,ip—

tetramethylpentane warrants serious consideration because the other potential product of the reaction, 2 ,2 ,3 >^4-"tetra­ de thy1pen tan e , is also desired in large quantities.


ever, inasmuch as the same' amount of each hydrocarbon is to be made, it can be seen that a method for the synthesis of

2 2 ,3 ,3 ,l|--tetramethylpentane alone Is desirable. Cline (11) has reported the synthesis of 2,3,3A ” tetramethyl-l-pentene by the reaction between 2 ,3-di-methyll-bromo-2-butene and isopropylmagneslum bromide; Me2C=C-CH2CHMe2 Me (1.6 parts) Me2C=9-CH2Br + BrMgCHMe2 Me Me2CHC(Me)2C=CH2 Me (1.0 part) The 2,3-dimethyl-l-bromo-2-butene is prepared by treating 2,3-dimethylbutadiene with HBr. vestigated in the present work.

This reaction was not in­


A. Preparation of the hydrocarbon by a Grignard alkylation

In 1903> Werner and Zilkens (56) reported a new hydro­ carbon synthesis which involved the alkylation of phenylmagnesium bromide and of p-tolyImagnesium bromide with methyl sulfate.

It remained for Houben, howevet*, to alkyl­

ate a Grignard reagent with an alkyl halide, and this type *

of reaction is often referred to as Houben's reaction:


prepared ethylbenzene in 25% yield by treating methylmagnesium iodide with benzyl chloride (25). Many workers have used this reaction for the synthesis of aromatic compounds.

Gomberg and Cone (22) (23) treated

triphenylmethyl chloride with a series of Grignard reagents and obtained the expected hydrocarbons in low yield.


(7 ) prepared neopentylbenzene in 38% yield from benzylmagnesium chloride and t-butyl bromide; Bert (5 ) studied the effect of benzyl chloride on different Grignard reagents and obtained good yields of the alkyl benzenes. In 1913 > Sp&th made the classic study in this field (49).

He noted that the alkylation reaction was slow and

required considerable heat.

Usually the Grignard reagent

was prepared, freed from ether by heat, the alkyl halide was. added, and the mixture was heated at a temperature between 50° and 17O0 C, for 2 to 48 hours.

The yields of mixed


alkylation products, R R 1, varied from 0$ to 37$ > ‘ the phenyl- and henzyl-magnesium compounds giving the best yields.

Varying yields of the coupled product formed by

the joining of two alkyl groups from the halide used were also noted; for example, propyImagnesium bromide with octyl bromide gave 29$ hexadecane. Sp&th explained the reaction products on the basis of free radicals:

RMgX + R ’X ' ^ R . + R i + MgXX* .

The free

radicals can then react in a number of ways, a few of which are indicated: R. + R I — R. + R.

RR* > RR

R. + R! R. +■ R.

R_jj + R*.jj ^


Edgar, Calingaert, and Marker (15) made a practical application of the reaction in the aliphatic field by prepar-ing two heptanes which could not be synthesized by the usual method of dehydrating an alcohol and hydrogenating the olefin or mixture of olefins.

Mercuric chloride was

used as a catalyst: n-PrMgBr + t-BuCl ---» (CH^)5CCH2CH2CH5


EtMgBr +■ t-AmCl --- > GHjCHgCCCH^JgCHgClHj


Marker and Oakwood (39) made a series of hydrocarbons in 11$ to 20$ yields by reacting ethyl, propyl, butyl, and amyl Grignard reagents with t-butyl chloride and t-amyl chloride in the presence of cuprous iodide.

5 Oldham and Ubbelohde (i|.0) used a modified Grignard pro­ cedure to prepare symmetrical hydrocarbons from primary alkyl halides.

Actually, this modification employs a Wurtz-

type reaction rather than a Grignard-type reaction.

In the

preparation of a Grignard reagent, three reactions occur: (I)


+ Mg --- > RMgl


2RI + Mg --- *• R2


2RI +Mg


--- * R-H+ R + H +'

The extent towhich each reaction occurs depends largely on the alkyl halide used, although the experimental conditions used also have an influence.

For example, methyl and ethyl

halides give mainly reaction (I), while tertiary halides show a tendency to give hydrocarbons according to reaction (III).

For many years it was thought impossible to prepare

allyImagnesium bromide because diallyl was formed quanti­ tatively as shown by equation (II). If the Grignard reagent Is treated with iodine, the alkyl halide Is regenerated: RMgl + I2 -- * RI + Mgl2 Oldham and TJbbelohde prepared the Grignard reagent in the usual manner and obtained the equilibrium mixture of pro­ ducts formed by the three competing reactions.

The alkyl

halide was regenerated by adding the calculated amount of I2 , then magneslunijand the three reactions occurred again. Repeated additions of I2 and magnesium gave yields of 60-65$ of long chain paraffins.

Unsaturated halides of the allyl type are very re­ active toward Grignard reagents.

Allyl bromide reacts

readily to give 1-olefins in good yields (27) (65).


lenic Grignard reagents can be used, but a catalyst such as the cuprous or cupric halides must be employed (13)• In reactions with ^-substituted allyl bromides, com­ plications arise; for example, /S-ethylallyl bromide gives two products with ethy Imagne sium bromide (J4J4.): EtMgBr + EtCH=CHCH2Br ---► EtCHsCHCHgEt Et2CHCH=CH2 These substituted allyl bromides also undergo coupling re­ actions to give the two expected dimers (I4.3 ) Carothers and Berchet (10) made series of orthoprenes using this rearrangement: CH2=C-CHCH2C1 + RMgX --- ► CH2:C=CHCH2R + CH2=CCH=CH2 Phenoprene and heptoprene were prepared in 2i$ yield, but the purifications were difficult. These authors also studied the mechanism of this re­ action in connection with their investigations on acetylene polymers (9)*

The study involved the chemistry of three

compounds: CH=CCHrCH2 (a)





Treatment of (a) with HC1 gives (b); (b) reacts with water normally to give the carbinol.

(b) with HX in the presence

7 of CuX gives (c).

(b) with RMgX gives the derivative of

(c) and (b); however, (c) will not react with RMgX, so the rearrangement observed must follow the reaction of (b) with RMgX. ‘ Carothers postulated the formation of a complex to account for the isomerization of (b) to (c) in the presence of CuX: t RCH-CH , ■ • , « ■ CH-, ---■ : *' i : / 5 . 4 ‘ .= . v *‘ _ •; 1 x“ \ •* .


RCH=CH r \ .. X, * / m-»x

* RCH-CH . i, \ V Xf-

• . OH, 2


OH, *•' 2

, ♦


He suggests that the Grignard alkylation could be set up on the basis of a co-ordinated complex and need not involve free radicals: R


\/ Mg



R >


\/ Mg

--- >

RR ’ + MgXp



The V-Jhitmore-George theory involving a six-membered .ring (59) gives a clearer picture of the rearrangement: CH ■ / \ CH2=C CH2 I ' Br (b)

CH » \ 0H2=0 CH2 * I R-CH2 ^ B r Mg^OEtp I * X

CH >

/ X 0H2:0 CH2 I R-CH2

derivative of (c)

8 Cline’s (11) synthesis of 2,3,3 ,l{.-tetramethyl-l-pentene is another example showing the tendency of 0-substitu­ ted allyl bromides to rearrange: Me2C=CCH2Br Me

+■ BrMgCHMe2 — * Me2C=CCH2CHMe2 Me Me2CHC(Me)2C=CH2 Me

In addition to the experimental conditions and the alkyl groups involved in the alkylations, it has been found that the halogen of the alkyl halide and of the Grignard reagent also have an effect on the reaction.

Vavon, Calin,

and Pouchier (55) studied the rates of reaction of ethylmagnesium halides with various organic halides, and the reaction of allyl bromide with various Grignard reagents. They concluded that the reaction between the Grignard rea­ gent and halides was fastest with tertiary halides and slow­ est with primary halides.

For the Individual halides, the

iodide reacted faster than the bromide, the bromide faster than the chloride.

AlkyImagnesium bromides seem to react

slightly faster than the iodides or chloride, but not much. The rate of reaction was found to decrease after the reaction was 50% complete.


9 B. Preparation of the hydrocarbon through the dehydration of methylisopropyl-t-butylcarbinol The hydrogenation of olefins is probably the most widely used method for the laboratory preparation of paraffins.

Whitmore and Laughlin (6I4.) dehydrated methyl-

isopropyl-t-butylcarbinol and found that the main products were 3 ,3-dimethyl-2-isopropyl-l-butene and 2 ,3 ,3 ,lp-tetramethyl-l-pentene in the ratio of 3 to 1.

Another olefin,

2 ,2 ,3 ,i|.-*tetramethyl-3-pentene, was found in traces. The main obstacle in this preparation is a conveni­ ent source of pentamethylacetone, the reaction of which with methylmagnesium bromide gives methylisopropyl-t-butylcarbinol. This ketone is usually prepared by a two-step process in­ volving a reaction between t-butylmagnesium chloride and isobutyraldehyde (60) followed by the oxidation of the carbinol to the ketone with-a dichromate (17)«


method which is sometimes used is the methylation of diiso­ propyl ketone with sodamide and dimethyl sulfate


Greenburg (2) found that the reaction of methylmagnesium iodide with 3“iaethyl-3-bromo-2-butanone gave 2 ,3 ,3“^rimethy 1-2-butanol in 62%' yield.

Although this is the only

reaction in the literature in which the simultaneous alkyl­ ation and addition to the carbonyl group occurs in such high yield, the possibility of a similar reaction between Ph2CHC-Me

+ MgBrCl

14-. Addition (.5 1 ) H,

H. +

Me Mg I

5« Elimination of Hx (28) PhCHBr CHBrC -Ph PhCH=CBrC-Ph 1

+ PhMgBr —

PhCH=CBrC -Ph + PhH + MgBr 2

+ PhMgBr — * Ph2CHCBr=CPh + MgBr2 OMgBr

11 6. Replacement of X with rearrangement (48)„.

P Cl ■C-Ph H2 *0

MeMgBr — *■

7. Reduction (36)

rH |G1

H +

t-BuMgBr— ► H


iH Cl + isobutene (OMgBr h2 H

The replacement of the fX-halogen with hydrogen (meta­ thesis) is one of the most frequently observed reactions. Umnowa (53) (54) treated 2,4”( 3-ibromo-2,]4-c3.imethyl-3-pentanone with MeMgBr and obtained pentamethylacetone. Me2CBrC-C(Br)Me2 + MeMgI

^,0-MgI MejCC-CMe2 + MeBr

She identified the methyl bromide and postulated the inter­ mediate as a true Grignard compound after a study of the product formed on treating the substance with C02 . Lttwenbein and Schuster (38) considered the intermedi­ ate to be an enolate and wrote the reaction between diphenyl-bromomethyl phenyl ketone and PhMgBr a s : ,0 jDMgBr PhCC(Br)Ph2 + 2 PhMgBr — -* PhC=CPh2 + Ph£ +■ MgBr2 for they isolated an equivalent amount of diphenyl.

12 Howk and McElvain (26) believe the bromoketone can exist as the bromhydrin.

In the reaction between ethyl-

benzoylbromoacetate and PhMgBr they were able to explain the presence of the various compounds formed by assuming an equilibrium between the bromoketone and the bromhydrin; PhC(0H)-CBrC02Et _ ^

"° — PhCCHBrC02Et ^

,°Br PhC=CHC02Et

They present other evidence to prove the bromoketone and the bromhydrin exist together. Puson and coworkers (20) (21) treated Of,3 ,5-tribromo2,i|,6-trimethyl-isobutyrophenone with various Grignard reagents and found the 2 ,0% metathesis.

The melting point and mixed

melting point of the 2,4-dinitrophenylhydrazone was 94*5"

95°. Cuts 12-15, 36.7 S* (0o25 mole) of methylisopropylt-butylcarbinol, represent a 10,2% yield of tertiary alcohol. Dehydration of methylisopropyl-t-butylcarbinol (15$ HpS0)j) In a 1 liter flask with a ground glass joint were placed 32.6 cc. of 95$ H2S0^_, 320 cc. of water, and 216 g.; (1.5 moles) of methylisopropyl-t-butylcarbinol (n^^D 1.4433) The mixture was refluxed in CRE II for 3 hours and the

product was then taken off slowly at the head during 10,5 hours.

The organic layer was separated, washed with a

small amount of water and dried over C aC ^ .

It was frac-

ted through C-IV at 742 mm. Cut


B. J.

T. J.

Head T


1 2

2.4 3.0 15.6 13.0 15.1 15.0 17.3 16.9 5.6 13.2 13.4

123° 123 125

120° 121 122


3 4 5

128° 128 129 130 131 132 135 135 135 135 136 138 lk4



126 128 132 132 132

12k 126 129

6 7 8

9 10 11 12

14 R


lO.k 6.0 11.8

133 133 133 135 i4 i


131 131.5 132 132 132 132



1 ,11.190 iJ +196 1.4210 l,J+229 l.J+258

1.4282 1.4300

1.4306 1.4308 1.4308

1.4308 1.4518

Cuts 9- 13, 56.9 g., represent a 30.1$


There was no definite separa­

tion of 3 >3“‘!lme'fcfryl-2-isopropyl-2-butene as observed by Whitmore and Laughlin (64)* Valentine index at 20° by Dr. G. H. Fleming: Cut 12


Density at 20°: Cut 12

0.7612 g./cc.

Cottrell boiling point: Cut 12

133,2- 133.3/ 741.0 mm.


Hydrogenation of 2 ,3 ,3 ,l)--tetramethyl-l-pentene The hydrogenation was done in the American Instrument Company hydrogenator using the 500 cc, bomb.

A 1+6.6 g.

(0*37 mole) portion of 2 ,3 ,3,l+-tetramethyl-l-pentene Q /*\


D l.l4.306-l.li.308) was reduced using 5 S» of Raney nickel

catalyst and 250 cc. of anhydrous ether as solvent. The initial pressure was 1520 pounds per square inch at 250 and the bomb was heated to 76° to complete the reac­ The final pressure was 1280 pounds/sq. in. at 76°


and 1090 pounds/sq. in. at 30°.

The total time of reac­

tion was I4..75 hours and 1+ additional hours were required for cooling. The bomb was emptied and rinsed with 100 cc. of dry ether and the catalyst was filtered from the solution. The ether was removed on the steam bath and the hydrocarbon was fractionated through C-IV. Cut




Head T.


128 126 137 lk3 xI+6 il+i+

125 125 138 1U1 li+i 1JL+1



ll+i 1I4.I

1+0-120 136 137 138 138 138 138.5 138.5




1 2 3 k 5 6 7 R

0.1+ loo 1.9 5.9 5.18.7 9.5 9


1.14.020 1.1+186 l.il-215 1 1+221 1 1+222 1 1+222 1 1+222 1 1+222

. . . . .


Cuts I4.-8, 39.1 g. (0.305 moles) of 2 ,3,3 ,ij.-tetramethylpentane, represent an 83% yield of the hydrocarbon.


Valentine indices at 20° by Dr. G. H. Fleming: Cut 5 Cut 8

1.4222 1.4222

Density at 20°: Cut 6


Cottrell boiling point: Cuts 6 and. 7-


ll^0 .2°/729.0 mm. , . , * •

N .

•' ••'i

‘ ,-vi . ♦




Attempted preparation of the hydrocarbon through the ketone 3 ,3 ,l4.-trimethyl-2-pentanone

Preparation of 2 ,l4.-dlmethyl-2-bromo-3-pentanone In a 2 liter flask fitted with a stirrer and a drop­ ping funnel were placed 351), g. (3.1 moles) of diisopropyl ketone (l22-12ij.0/738 mm. j n^®D lJ.|.0C)3)*

The flask was

cooled thoroughly in an ice bath-and

g* (15& cc.,

3.1 moles) of bromine were added dropwise during 7 hours„ Air was bubbled through the solution to remove most of the HBr and the crude product was fractionated through CRE II.

The aspirator and pressure regulator were well

protected with a long soda-lime tube. Cut


Jack T. 108°

109 115

Head T.


58-87 106 108 108 108

130 mm*

When the head temperature had reached 108°, the pro­ duct was distilled at a 1:1 ratio. Cuts 3-5, 14-97.5 g. (2.57 moles) represent an 83# yield of 2 ,l|-dimethyl-2-bromo-3-pentanone.

The product was

colorless upon distillation, but soon turned violet and finally dark blue on standing a few days.

Hydrolysis of 2 represent a 77*3/^ yield of hydroxy-ketone.

This ketone was found to be contaminated

with unreacted bromoketone (see the preparation of trimethylisopropyl glycol). Another hydrolysis was done exactly as described above

except that the reaction mixture was heated for 21}. hours instead of 1J4. hours. Cut


Head T.



1 2

74 13.2 4.1


150 mm.


I.l|.l60 l.llJ+5 l.lp-94 l,l}27o 14-302 1 4-302 1 •14-303 1 •14-302

18.5 20.0

109 109

14-295 14290


108.5 108.5 108.5 108.5 108.5

1.1(286 I.I4.285 1.14288 1.14.285 1 .1^279

1.4275 l.li271




7.1 4*7


9 10 11 12

109 109


18.9 184


106 108


21.2 22.1

4 15

83 95




109 109





22.6 14.0



14 2 59 1,4238

2.!}.«din 11r opheny lhydr a zone Cut 6


1614.-168° 170-1710

The decreasing index of the fractions seems to indi­ cate that very little, if any, bromoketone remained unhydrolyzedo Preparation of trimethyllsopropylglycol In a 12 liter flask fitted for a methyl Grignard were placed 500 g. (20,6 moles) of magnesium turnings and 6 liters of ether.

Methyl bromide was run in until almost

all of the magnesium had disappeared.

49 To the Grignard reagent was added 1170 g. (9 moles) of 2 ,4-dimethyl-2-hydroxy-3-pentanone (3,4-dimethyl-3hydroxy-2-pentanone) during 15 hours.

The hydroxy ketone,

n20D l.lj.287- 1 ,1^ 31, was found to be contaminated with a considerable amount of bromoketone. After refluxing the addition product for 3 hours, the Grignard was decomposed with 6 N H2S0^.

The layers were

separated and the water layer was extracted twice with 1 liter portions of ether.

The ether was removed on the steam

bath and the residue was fractionated through CRE II after drying over K2C0j. Cut


Head T.

Press. 150 mm, 74


40-58 62

53.6 5 6


l.i{.007 1.4009



18.6 13.0

91 solid solid

The 2 ,4-dinitrophenylhydrazone of cut 1 melted at 95° and gave no depression with the same derivative of diisopropyl ketone.

Cuts 1-2 , 264.6 g. (2.32 moles) of

diisopropyl ketone, indicate that the starting material contained 3*74 moles of the bromoketone.

This Is based on

the reaction of methylmagnesium bromide with the bromo­ ketone (Section B) In which 62% diisopropyl ketone was formed by metathesis* Cuts 5-6 contain a considerable amount of methyl-

50 isopropyl-t-butylcarbinol as indicated by the constants and the odor.

This product is also to be expected from *

the bromoketone impurity. Cuts 'J-Q, 2914..7 S« (2.02 moles) of trimethylisopropyl glycol, were a white crystalline solid with a melting of 39-14-0°.

Leers (31|.) reported the constants of the glycol;

boiling point, 93“96°/li|- mm.; melting point, 39°* Preparation of 3 >3 ,l4--trimethyl-2-pentanone (a)

By the dehydration of trimethylisopropyl glycol In a 1 liter flask fitted with

700 cc. of concentrated

a stirrer were placed

IlgSO^. The acid was cooled to 5°

in an ice bath and was kept at 8-12° during the dehydration. To the acid was added during 1.5 hours 186.5 g* (1.27 moles) of trimethylisopropyl glycol in small pieces.


ing the addition of the glycol, the solution gradually be­ came orange-brown in color. ished, the ice bath was gradually to 21°.

After the addition was fin­

removed and the temperature rose

The solution was run slowly into 3

liters of water and steam distilled; the product was dried and fractionated through CRE II over I^CO^. Cut 1 2


Head T.

Press. 7^4-2 mm.



n^®D 1J4.O6O l.li-080 lJ+082 I.I4.IOO

51 Cut


Head T.

I 8 9 10 11 R


152 !52 !52 !52

19.3 17.2 19.1 11.8 15.2


D 1.1+217 I.I+230 lj|230 lJ+231 1 .1+23^

Cuts 1,2 and but several attempts to prepare an oxime failed. Cuts 8- 11 , 67*)+ g. (O.526 mole), represent a i|l ,5fQ yield of 3,3,l+-trimethyl-2-pentanone.

The 2 ,l+-dinitro-

phenylhydrazone of cut 9 melts at li|.80, the semicarbazone melts at I5O.5-I510 . Valentine indices at 20° by Dr. G. H. Fleming: Cut 8

9 10 11

1.4228 1.4230 1.4231 1.4235

Density at 20°: Cut 9

O.8395 g./cc.

Cottrell boiling point: Cut 9


152,)+-152.7o/7^ 0.8 mm.

Attempted oxidation of methyldiisopropylcarbinol Methyldiisopropylcarbinol was prepared from 10 moles

of diisopropyl ketone and a slight excess of methylmagnesium bromide in 72*3% yield by the method of Stas (50). In

a1 liter flask fitted with a dropping funnel,

stirrer and condenser were placed 61+ g. (0.5 mole) of methyldiisopropylcarbinol (106°/l50 mm., n

D 1 .1+350) an2,7 >7“t'®^':i'aniethylC'CtaneJ about 16% of the neopentylcar­ binol used in the reaction went to form the alkyl dimer. No previous reference to the formation of a hydrocarbon of this type during the preparation of an alkyl chloride from an alcohol by the thionyl chloride method could be found. No explanation as to the mechanism of this reaction can be given.

It is obvious that the dimer is formed by a

reduction of some kind and thus an oxidizable compound must be present.

Of all the potential reducing agents available

during the reaction, SOCI2 is probably the most likely to be involved because the other reagents upon oxidation would give organic compounds which could be separated. The reactions of isoamyl alcohol, 2-ethylbutanol, and benzyl alcohol in pyridine with SOCI2 produced no detect­ able hydrocarbon dimers.

The action of neopentylcarbinol

with S 0C 12 to give the coupled hydrocarbon is apparently an isolated reaction. When Carney(67) attempted to run a Wurtz reaction on the neopentylcarbinyl chloride, he found that the first addition of a small amount of sodium resulted in an explo­ sion.

This ease of reaction of the chloride might explain

6l why the dimeric hydrocarbon is formed during the prepara­ tion of the chloride*

The presence of two alkyl groups on

the ^-carbon might also be a clue to the cause of this queer behavior, as abnormalities have also been reported in some of the reactions of t-butylacetyl chloride.



Preparation of t-butylethylene Tertiary butylethylene was dehydrated by passing pinacolyl alcohol over alumina at 360^*

The apparatus

(77) consisted of a horizontal glass tube of 25 mm. bore packed with 20 mesh activated alumina for a distance of

55 cm.

The tube was heated by means of a nichrome heating

element controlled by an external resistance and the temp­ erature was measured by a thermocouple. The dehydrator was heated to 360° and one mole (102 g,) of pinacolyl alcohol ( n ^ D l,ip.51> 120°/7lj.0 mm,) was run into the tube from a dropping funnel during nine minutes* The gases coming from the tube were cooled first by a stream of air and then run through a spiral condenser into a 300 cc. erlenmeyer flask cooled in ice.

A dry ice trap

was attached to the erlenmeyer flask to catch any low boil­ ing material.

After the alcohol was added, the tempera­

ture of the tube dropped to 315°•

Ery air was then passed

through the system for 1,5 hours to remove any water or organic material in^the tube. One cubic centimeter of material had collected in the dry ice trap and this was combined with that in the re­ ceiver and the layers were separated.

The water layer

weighed 11 g. and the wet organic layer weighed 87.2 g.

6? The

o le fin

w as

d rie d


J^C O j


fra c tio n a te d

th ro u g h

CRE I. Cut


Jack T.

Head T.

Press. 736 mm.


83 124 1J.5


6.0 3 08 50.0



10 11 12





1.3740 1.5748 1.3746 1.5756 1.5776 1.5795 1.3010 1.3830 1.3872

70 73 119 121


1.L.059 1.4109


Cut 13, 30 g., represents 0.294 moles of unreacted pinacolyl alcohol.

Cuts 1-4 (21.4 SJ 0.255 moles) repre­

sent a 25.5?o yield of t-butylethylene based on the total starting material, or 36.2% based on the alcohol actually used.

The 11 g. (0 .6l mole) of water separated from the

crude product compares fairly well with the 0.70 mole of pinacolyl alcohol which was dehydrated.

Preparation of 3 ,3-dimethyl-l-bromobutane The neopentylcarbinyl bromide was prepared by passing HBr into t-butylethylene in the presence of benzoyl perox­ ide.

The olefin was obtained from stock and was prepared

by C. I. Noll and R. K. Smith. CRE I before use.

It was fractionated through

61j. In a three-neck 1 liter round, bottom flask we re placed 251 g. (2.99 moles) of t-butylethylene (n20,%)

1 *57 ^2 )> 2I4.O cc. of dry benzene, and O.15 g. of benzoyl peroxide.

The flask was fitted with an efficient mercury—

seal stirrer, a condenser with a CaCl2 drying tube attached, and a 7 mm. glass inlet tube which extended 2 cm. below the surface of the liquid. The flask was cooled to -Ip0 in a salt-ice bath and HBr was bubbled through the solution. ated by dropping

The HBr was gener­

on naphthalene and was purified by

passing the gas through a tube containing red phosphorus and CaCl2» After 10 hours, the mixture had taken up 90 g* of HBr0 About 15 g. of anhydrous Na£S0^ was added to the solution and HBr was bubbled through the cold liquid for 10 addi­ tional hours.

The total weight of HBr absorbed was 260

g• After standing over night in the refrigerator, the product was poured into 200 cc. of H2O and the layers were separated.

The organic layer was washed with 100 cc. of

20%' Na2C 0^ solution and then 3 times with 50 cc. portions of cold water.

After drying over K2C0^, most of the ben­

zene was removed through an l8 inch indented column and the residue was fractionated through Column CRE I at 150 nim.

65 Cut 1 2

Wt. 15.2 20.5


9 10 11 12


12. 2 21.2 22.6 22. 9

oo 90 90


1.4455 l.ffi49 1 .1® i .1jJj1i8

27.3 24.6 25.4

90 90


90 90 91 91 91 91 91

86 86 86 86 86 86 86.5 86.5 86.5 87 87 87 87 87 87 87 85


23.0 23.0




1 n76i 1.4730




58-k6° 7°


20 21 22

g° °

n20* ^




Head T.


I 6

Jack T.

23.6 24.7 22.5 22.4

91 92 92 92


1.13518 1.4448 '

1.4448 1.4448 1 .1® 1.4448 1.4448

1.4448 1 .1*448 1.444-8

1.444s - w m



Cuts 5“22, 598.3 S* (2*42 moles) represent an 8 0 .9$ yield of neopentylcarbinyl bromide.

No olefin was re­

covered. Preparation of 5 ,3~dlme't:hyl-l-butanol (a)

By the oxidation of Me^CC^Cl^MgBr The oxidation of neopentylcarbinylmagnesium bromide

was done in a 2 liter 3-neck flask fitted as ustial for a Grignard reaction.

The Grignard reagent was prepared dur­

ing 3 hours from 75.3 g. (3.1 moles) of magnesium turnings, 398 g. (2.42 moles) of 3,3-dimethyl-l-bromo-butane (86-870/ 150 mm., n 20*^D

1.1*448) and 1 liter of anhydrous ether.

66 After the addition of the bromide was finished, the solution was stirred for two hours, the dropping funnel was removed, and a tube was inserted which extended to within

0.5 inch of the surface of the liquid.

Oxygen was passed

through a Gilman trap over the well stirred mixture which l was cooled with ice. |The rate of glow of oxygen was con— trolled so

that the ether

refluxed slowly.After 5 hours,

fthe mixture suddenly.became solid so that stirring was in­ efficient.

The solid was

were added, but

broken up and 500cc. of ether

reaction still could not bestirred.

The product was poured onto ice with some evolution of heat.

The Mg(0H)2 was neutralized with HC1 , the layers

were separated, and the HgO layer was extracted twice with

200 cc, portions of ether.

The ether extract was dried

over KoC0-,, the ether was stripped off through an indented column and the residue was fractionated through CRE I. Cut






3 5

*•§ 10.8 11*7




8 9

10 11 12

11.2 14.0

12*5 11.5

13 i4

10.8 ll.l 12*4 11.8






Head T.

90° 104 104 106 107 107 105 105

105 106 105

105 106 106

97 ft 99 100 100 100 100 100


99.5 99.5

99.5 1

100 100 100



150 mm. 1 .J4.IO7 l.J-i-151 l . » 1 .4140

1.4139 1.-P-39 1.-1-139 1.4-139



150 ram. 1*44.139


1 4-139

I.I4-I4.O 1 .{4-139


67 Cut


17 18 19

11.1 11.6 11.1

Jack T.

Head T.

io6° 105 105



ioo° 100

The oC-naphthylur ethane of cut 10 melted at 8l°; the mixed melting point with a known sample of this derivative melted at 8l°. Cuts 3-20, 203.6 g. (I.99 moles), represent an 82.3^ yield of neopentylcarbinol based on the bromide which was used. Valentine index at 20° by Dr. G. h. Fleming: Cut 10


Cottrell boiling point: Cut 10 (b)

lij.2jp-lJ+2.6o/7^1.0 mm.

By the action of ethylene oxide on t-butylmagnesium chloride A '5 liter flask with a trident was fitted with a mer­

cury seal stirrer, a dropping funnel, and a condenser.


the flask were placed 150 g. (6.17 moles) of magnesium turnings and 1500 cc. of anhydrous ether; to this was added 555 g» (6 moles) of t-butyl chloride in 650 cc. of ether during 6 hours. The solution was cooled in an ice bath and a cold solution of ethylene oxide in ether was added to the mix­ ture -in small portions.

Approximately 33O g. of ethylene

oxide in if.00 cc. of ether were added during 1.5 hours.


68 the ethylene oxide was added, the mixture gradually, took on a gray-white appearance, hut this disappeared after about 2 hours of stirring. After 2I4. hours of stirring, the solution was waterclear.

The flask was placed on the steam ba.th,- the conden­

ser was removed and replaced with an adapter and a down­ ward condenser and 500 cc. of ether were distilled off. Five hundred cc. of dry benzene were added and after 500 cc. more of the ether had distilled, -another 500 cc. por4

tion of benzene was added.

The heating was continued

until the distilling vapors had reached 65°.

The adapter

was removed and the upward condenser was inserted.


500 cc. of benzene had been added (total - 1500 cc.), the flask was heated on the steam bath for 5 days.

After 2

days the material became gelatinous. The Grignard complex was decomposed by the addition of 1^0 through the dropping funnel.

No heat was given off

and there was no appreciable evolution of gas.

About 2

liters of B^O were added and the mixture was steam dis­ tilled, a total of 5 liters of distillate being collected. No more oil distilled upon further steam distillation of the residue.

The layers from the distillate were separ­

ated and the H2O layer was again distilled; about 30 cc. of oil were recovered from this.

The oil layers were com­

bined and heated with 1 liter of E^O containing 200 g. of NaOH for 2 hours.

This product was again steam distilled


and the benzene layer was separated.

The benzene layer

was stripped through an indented column and the residue was fractionated through ORE I at 736 mm. Cut


Jack T.

Head T.


l \ ? k

8.5 io-2 11 ^ 7*9 10.7

1290 , 160 165



88-107° 127 ■ 137 I4.O 1I+5 ll+5 ll+5 ii+7

I.I+510 i.i+217 1.1+171 1.1+170 1.I+170 I.I+172 I.I+172 i.lUk

5 6 1 6 R

8 -2


Xo §2


The refractive index of pure neopentylcarbinol is


It can be seen that none of the above material

is pure, but cuts ip—8, 1+1.7 &• > represent a 6.8$ yield of the crude alcohol. The ^(-naphthylurethane of cut 5 melts at 8l° after 2 recrystallizations from petroleum ether. The carbinol prepared above was combined with that obtained in a similar preparation and refluxed with 20$ NaOH for several hours.

After fractionation, the carbinol

had an n20D of 1 .1+156-1 .1+158. Preparation of 3 ,3-dimethyl-l-chlorobutane (a)

By the action of ZnCl2-HCl on the alcohol The preparation of the chloride from the alcohol was

carried out as described in Organic Syntheses (75)•

In a

500 cc. erlenmeyer flask were placed 52 cc, (0.1+ mole) of cold HC 1 and 5I+.I+ g. (0 .1+ mole) of pulverized anhydrous

ZnCl2 .

To this mixture was added 20.


(0.2 mole) of

neopentylcarbinol (n20D 1J4.156). After refluxing for

hours, the upper layer was sep­

arated and heated with an equal volume of cone. H2S0^ for

0.5 hours.

The dark purple solution was then distilled

until fumes of SO^ began to come over.

The distillate was

dried over ^ O O j and distilled from a small flask at 733 mm. Cut


I ? £ 5 ° 7


Head T.


i-aaJi.9 M i° 2 3.0 1*5 °*5 1*6

1:L& 118 120 12I+ 155 —

i.!a& 1.I+167 14169 1.1+171 1J.+202 1J-+3I+1

Cuts 2- 5 , 8 g., represent a 33# yield of crude 3,3dimethyl-l-chlorobutane. (b.)

By the action of S0C12 on neopentylcarbinol A 3-neck 1-liter flask was fitted with a condenser,

a mercury seal stirrer and a dropping funnel.

In the flask

were placed l80.7 g. (1.76 moles) of neopentylcarbinol (99.5- 100°/l50 mm.; n20D l.l+ll+3 ) and 139 g. (1.76 moles) of stock-pyridine dried over KOH.

The flask was cooled in

a salt-ice bath and 192 cc. (3li+ g., 2.61+ moles) of stock S0C12 were added to the well stirred mixture during 1.5 hour s. Soon after the addition of S0C12 was started, a yellow

solid began to form.

Vi/hen the addition was finished, the

entire solution was a bright yellow color due to the sus­ pended solid.

After the SOCl^ was added, the mixture was

heated on the steam bath for 2.5 hours. solid dissolved and 2 layers formed.

Upon heating, the

The bottom layer grad—

ually turned black, but the top layer remained colorless* The mixture was poured onto 200 g. of ice and 150 cc. of conc. HC 1 .

The layers were separated with difficulty

because a brown flocculent solid precipitated.

The solid,

however, was soluble in Na2C0^ and the organic layer was washed until free of acid with 10% carbonate, then twice with 50 cc. portions of H20 and dried over K2C0j. An attempt was made to fractionate the chloride layer However, after about 10 g. of liquid dis­

through CRE I.

tilled at 118° the temperature began to rise. charge was 157

As the

this indicated that only a very small

portion of the product.was the desired chloride. The fractionation was stopped and the residue and the cuts were treated with 110 g. of pyridine and 256 g. of S0C12 as before. for 5 hours.

This time the reaction mixture was heated

The mixture was poured onto 200 g. of ice

and 150 cc. of HG1 and the chloride layer was washed with

10# Na2C0^ and water until it was neutral. was observed.

No brown solid

The product weighed 10lq g.

The pyridine-H2 0-HCl layer from the second treatment was steam distilled in an attempt to recover more of the material.

Only 0.5 g. of oil was recovered from 800 cc. of

72 the steam distillate. The chloride layer was dried over I^CO^ and frac­ tionated through CRE I. Cut


Jack T.

Head T.


1 2


125° 127


726 mm.

4-5 11.4

3 4 5

ll.l 11.8



134 135

9.9 5.4




7.9 3.7


118.5 118.5 118.5 118.5 118 no reflux at head



120 150 started to solidify in cutter

The residue weighed 52 .2 g.

It crystallized when

cooled in the refrigerator. (1) the hydrocarbon from the residue The 52.2 g. of residxi.e from the chloride preparation was crystallized from 75 cc»


After three re­

crystallizations from this solvent, 5*5 g» were obtained. liquor.

white solid

Another gram was obtained from the mother

After evaporation of all the methanol from the

residue, 5.2 g. of a dark oil with a camphoraceous odor remained. The large loss of material in this recrystallization was undoubtedly due to volatilization of the solid. (T. P. Carney reports a 5p% loss of the C12.hydrocarbon by exposing the solid to the air for 12 hours.)

The white solid had a sealed tube melting point of and a mixed melting point with known 2,2,7,7tetramethyloctane (from a Wurtz reaction by T. P. Carney) was the same.

The material contained no chlorine, sulfur,

or nitrogen. After standing in a stoppered flask for a day, some of the solid had sublimed and crystals had formed on the sides of the container near the cork.

The hydrocarbon

prepared by Carney acted the same, and the sublimed cry­ stals were similar in appearance, A molecular weight determination was made on the solid by the freezing point lowering of benzene.


values of 165 and 169 for the molecular weight of the compound check fairly well with the value of 170 for a hydrocarbon C12H26* It is difficult to make an estimate of the yield of hydrocarbon obtained In this reaction because of the loss In handling.

However, if the residue before extraction

is assumed to be mostly the hydrocarbon (because of the ease of freezing out the crystals), the difference in weight between the residue (52,2 g.) and the recovered oil (5.2 g.) gives the weight of hydrocarbon as 27 g.


25 g. yield of the coupled hydrocarbon, represents lG)i of the neopentylcarbinol used in the reaction. (c)

The constants of 5 ,5-d.imethyl-l-chlorobutane

Cuts 1-8 Inclusive from the fractionation in (b) were

combined, washed with 10%' N a ^ over K^CO^o

and water, and dried

The material was fractionated through CRE I

at 727^!Cut


Jack T




7 R

^ 0y

Head T



118° 118 118 118 118 118 118 118

16/1 21/1 17/1 15/1 16/1 / x 13/1 '/i

1.1*165 ..... ilii65 ..... ij*i6i* • • t o •• •• •• • 0 1.1*161*




The indices were taken on the Valentine Refractometer by Dr, G. H. Fleming. The weight of neopentylcarbinyl chloride was 51*9 6* This is a 2l*.l*/£ yield from 180,7 g* (1 «7^ moles) of neo­ pentylcarbinol o The alkylmercurlc chloride was prepared by the method of Shriner and Fuson: mp. 158° (Bernstein: 133°)• The Grignard reagent was prepared and oxidized to the alcohol.

The melting point of the

1 *b21 1,427


Popkin reported a 70# yield of 2-ethy1-1-chiorobutane (l25.5°/74l mm., n20D 1.4227) by this method. 2-16, 229


represent a 76/0 yield of the crude chloride.

Cut 18 was a yellow oil with a sweet odor resembling an ester or a ketone.

The remainder of the cuts were

also yellow, cuts 20, 21 and 22 having a disagreeable odor.


The action of S0C12 on benzyl alcohol in pyridine The reaction was done as described for the other

alcohols using 2.0 moles of Eastman's yellow label benzyl alcohol and the other reagents*in a proportionate amount. Cut 1 2 3 k 5 6 7 8 9 10



k.l 8.0 1I4.6 19.6 22.6 23.5 22.0 23.5 20.5 17.1




70 mm.

n20D I.S378

105 103 1°3 1°3

1.5390 1.5391 1.5391 1.5391

103 103 103 103 102

1.5391 1.5591 1.5391 1.5391 1.5391

The r e si due distilled. Cut 1


2.1 g. 2.6

1 .55^0 1.5558

Decomposition occurred as white fumes were evolved during the distillation.

There was no evidence that any di­

benzyl had formed. Cuts 2-10 , 171.14. g. (1.35 moles) represent a 67,8% yield of benzyl chloride.



1 . Neopentylcarbinol was prepared in 82.3# yield from neopentylcarbinyl bromide by the oxidation of the Grignard reagent,,


Neopentylcarbinyl chloride was prepared from neopentylcarbinol in

yield by the tHionyl^chloride method. Vr

The physical constants of the chloride were determined and the reported melting point of the neopentylcarbinylmercurie chloride was corrected. 3.

The action of SOCI2 on neopentylcarbinol in pyridine was shown to give 2 ,2 ,7 ,7-tetramethyloctane.


reaction accounted for 16fo of the neopentylcarbinol,

1|., The action of SOCI2 on isoamyl alcohol, 2-ethylbutanol, and benzyl alcohol gave no coupled hydrocarbon.


formation of the hydrocarbon in the case of neopentyl­ carbinol is apparently an isolated case.







The work of a large number of chemists has shown that tertiary chlorides are more easily alkylated by a Grignard reagent than are primary chlorides (Part 1 , Sec­ tion A).

This fact, together with the relative unreacti­

vity of neopentvl chloride, suggested the alkylation of l,2-dichloro-2-methylpropane with methylmagneslum bromide as a possible preparation of neopentyl chloride.

If the

tertiary chlorine atom were replaced with a methyl group, the tendency for the primary chloride thus formed to react with the methylmagneslum bromide should be very limited. Ivle^C— CH^Cl



)(— » Me^CCH^l -I- MgBrCl

The only method for the synthesis of neopentyl chloride is that of Whitmore and Fleming (99) (100), al­ though Karnatz (91) did succeed in preparing the chloride in i y i e l d from neopentyl alcohol using thionyl chloride and pyridine.

The usual preparation of neopentyl chloride

consists of first reacting methylmagneslum bromide with t-butyl chloride to get neopentane, followed by the chlor­ ination of the hydrocarbon to give the chloride. The preparation of 1 ,2-dichloro-2-methylpropane has been accomplished by the chlorination of Isobutane (85) (88),

iso b u ty l


t-b u ty l

ch lo rid e alco h o l



( 9^ 1- ) , and

t-b u ty l

Iso b u ty len e

ch lo rid e


(81+) (92) (95)

(97)* &nd. by the treatment of 1—chloro—2—hydroxy—2— methylpropane with HC 1 (89). The work of the Shell Development Laboratories (8ip) on the chlorination of isobutylene is especially interestiftgj for they showed, that the reaction, when carried out in the presence of light, gives a good yield of 1,2dichioroisobutane by the addition of chlorine, but that in the absence of light, the main reaction is the substi­ tution of chlorine to give 95$ methallyl chloride. Hersh and Nelson (90) investigated various methods for the preparation of the dichloride, and concluded that the best method is by the chlorination of t-butyl chloride and this method was used in the present instance. The alkylation reaction gave no isocrotyl, methallyl or neopentyl chloride.

However, almost 50% of the di­

chloride was recovered unchanged, and under more vigorous conditions, such as higher heat and a longer reaction time, the preparation of neopentyl chloride by this reac­ tion might be realized. The reaction of l|_,l4.-dimethyl-3-bromo-2-pentanone with me thylmagne sium bromide is another example of the type of reaction discussed in Part 1 , Section B.

It was found in

the case of 2,^-dimethyl-2-bromo-3-pentanone that the re­ action with methylmagneslum bromide resulted in 62%> meta­ thesis (diisopropyl ketone) and 10'% addition and alkyla­ tion (methylisopropyl-t-butylcarbinol)»

In the present

case, the reaction of ^-»l|”di:methyl-3“bromo-2-pentanone with me thylmagne sium bromide gave 35.5$ metathesis (methyl neopentyl ketone), but the amount of tertiary alcohol formed was not determined. The lower yield of metathesis product in this case lends support to the theory that the ratio of the meta­ thesis product to the tertiary alcohol is determined by the reactivity of the carbonyl group.

The carbonyl group

of methyl neopentyl ketone (and its bromo derivative) is attached to two primary alkyl groups, while the carbonyl group of diisopropyl ketone (and its bromo derivative) is attached to two secondary groups; the carbonyl group of methyl neopentyl ketone should be expected to be more re­ active than the carbonyl group of diisopropyl ketone be­ cause of the steric factors involved. Aston and Greenburg (83) recently reported a new acid synthesis which involves the treatment of an ct-bromoketone with sodium methylate in dry ether to give the methyl ester of the acid.

They showed that the reaction of I4.,!).-dimethyl

bromo—2—pentanone with sodium methylate in dry ether gave a 73$ yield of methyl methyl-t-butylacetate (82). In view of Paworsky’s work on the action of alkali on bromoketones (87), it was desired to learn the effect of alcoholic KOH on this bromoketone.

It was found that

the rearrangement could be done with 10$ methanolic KOH, but the yield of ester was only 25$.

S' \:



The treatment of 2 ,l4.-dimethyl-2-bromo-3-pentanone

jl t.

with 10fa methanolic KOH gave no rearrangement to methyl dimethylisopropylacetate.

This was to he expected, as an

I '


As ton-Greenburg rearrangement on this bromoketone was also unsuccessful (98).

The product that was formed in the re­

action has not been identified, but judging by the boil­ ing point and the method of preparation, it is either


2,[|_-dimethyl-2-hydroxy-3-pentanone or 3»^“dimethyl-3hydroxy-2-pentanone.

In any event, the product formed

in this hydrolysis is not the same as that formed by the Na^CO^ hydrolysis of the same bromoketone (Part 1, Section C.).

Although the boiling points of the two pro­

ducts are very close, both the melting point of the 2,lpdinitrophenylhydrazones and the refractive indices are very different.



Preparation of 1 .2-dlchloro-2-methylpropane In a 1-liter 3-neck flask were placed 703 g. (7.60 moles) of dry t-butyl chloride (n20D 1.3860).

A small

glass hydrometer was made and calibrated to float at a specific gravity of 1 .09.

A Liebig condenser was inserted

in the center neck of the flask, the top of the condenser was connected to a suction flask (used as a trap) and the outlet tube was placed in a beaker of cold water to absorb the HC1 evolved,,

Chlorine was passed through a trap and

then beneath the surface of the t-butyl chloride; a Ttube was inserted in the line between the trap and the reaction flask so that a portion of the chlorine could be by-passed in order to control the reaction.

The third

neck of the flask held a thermometer. 'The reaction was illuminated with a 100 watt lamp placed 2 inches from the flask. Chlorine was bubbled through the solution slowly, the temperature began to rise and the liquid took on a strong yellow color.

When the temperature reached J4.O ,

a rather violent reaction began and .the liquid flooded half the condenser.

The yellow color of the solution dis­

appeared in about one to two minutes and the chlorination proceeded quite smoothly.

The heat evolved by the reaction

was sufficient to keep the temperature above that needed for the chlorination.

The speed of the chlorine addition

was regulated so that a slow reflux was maintained and no yellow color developed in the liquid. Chlorine was passed into the solution for 8 hours and, although the reflux was quite slow, the temperature of the solution was 62°.

The hydrometer did not float.

The mixture was washed with l80 cc. of water and then with l|-00 cc. of 5% NagCOj.

The density of this material was

measured with a hydrometer and was 1.075 g./cc. at room temperature.

The organic layer was dried over CaClg for

half an hour and placed over fresh CaCl5-KoC0, for 12 ^ 2 3 hours. The mixture of chlorides was distilled from a 1-liter distilling flask and divided into 3 portions? (a) 50-100°, (b) 100-120°, and (c) residue over 120°. The second fraction was purified through CRE II. Cut


Head T.

Press. 726


?o D








3 4. 5 6 7 6 9

10.6 18.1 55, k 58.3 33.9 50.2 14.6

106 106 106 106 106 106 —

1.4-350 1.4-369 i.i3§9 1J+369 i.U.370



1.070 i^370


Cuts 1,2 and 3 were combined with the low boiling fraction and the residue was combined with the high boil­ ing fraction.

The products from the chlorination of t-butyl chloride were thus divided into 3 portions; (a)


low boiling fraction consisting principally of

t-butyl chloride.

Weight; 205 g*

(b) A pure fraction of 1 ,2-dichioro-2-methylpropane (l06°/736 mm., n20D 1 .I+369-I.1+370). Wt; 250.5 g. (c) A high boiling fraction of poly-chlorides. Weight; 190 g. The yield of l,2-dichloro-2-methylpropane was 25.9^5 after correction for the recovered t-butyl chloride, the yield was Reaction of methylmagneslum bromide with l,2-dichloro-2methylpropane In a 1-liter 3-neck flask on the steam bath were placed 127 g. (1 mole) of 1 ,2-dichloro-2-methylpropane (106°/726 mm., n2®D 1J4.369) in 75 cc« A

anhydrous ether.

thermometer was placed in one neck of the flask and a

dident for a condenser and a dropping funnel was placed in the other neck.

The steam was turned on gently and the

mixture refluxed with a solution temperature of 63°.


the dropping funnel were placed 3^1 cc. of 2.77 N methylmagnesium bromide (1,0 mole). When the methylmagneslum bromide was started to drop into the mixture, the solution immediately became turbid. A white, cloudy gas was noticed in the flask, but no gas was passing out through the Gilman trap.

During the addi—

tion of the Grignard reagent (J4..5 hours), very little gas was evolved*

The solution refluxed at 51*"5 and was allowed

to stir at this temperature for 16 hours*

Only a few

grams of white solid precipitated. The flask was fitted for distillation so that some of the ether could he removed.

As the ether distilled, the

temperature of the reaction mixture gradually rose, gases were given off through the Gilman trap and a white solid precipitated in the flask.

Ether was distilled until the •4

solution temperature reached 66°; the mixture was quite thick with precipitated solida About 500 cc, of water were added dropwise to the complex and considerable heat was evolved.

The residue

was dissolved in 6 N H2S0^, the water solution was extrac­ ted twice with ether and the organic material was com­ bined with the ether which had been distilled during the reaction.

Most of the ether was removed through an in­

dented column, and after drying over CaClg for a short time, the residue was fractionated through CRE II over fresh K^CO^. Cut


Head T.


1 2

9.7 6.3

IlO° 5


q t:* M

■14. 4

l 1 7






loJLp 105,5 106


1.351+5 1*557i 1.3690

I.{i-03P 1 4 1^14280


No attempt was made to distil any more product be­ cause the residue was apparently the starting material, l,2-dichloro-2-methylpropane.

About l^Qfo of the’di-

chloride was recovered, assuming the residue to be this compound. No isocrotyl, methallyl, or neopentyl chloride was found. Reaction of i-t-^-dimethyl-^-bromo-S-pentanone with methy1magnesium bromide ' " The l4.,lj.-dImethyl-3-bromo-2-pentanone was prepared as described by Aston and co-workers (l6 ). In a tion were

2 liter 3“ne°k flask fitted for a Grignard reac­ placed 62,5

g. (2.57moles) of magnesium turn­

ings and 800 cc. of ether.

Methyl bromide waspassed


until only a small residue remained. To the Grignard was added 212.3 g. (1.1 moles) of i).,!}.dimethyl-3“bromo-2-pentanone (100-115°/70 mm.) in 150 cc. of ether during 3*5 hours* solution,

a bubble of

As each drop hit the Grignard

gas cameout of the Gilman trap.

The reaction was allowed to stir at room temperature for 6 days and was then decomposed on 500 S» in which 100 g. of NH^Cl were dissolved.

ice water

The organic

material was separated by steam distillationandfraction­ ated through CRE II over KgCO^.


wt. _

Head T.




3 *{+

37- 118°




10 *i

i6i i 5

m n 1? ■ 12


14 R




90 ^°3 ^ 82.5

ij+oi.0 1.1*050 1* W 1 .1+206

P*P |i -oi+ 4*5 • • 103 5 .9 . —

o89 56

10.9 9.1

i.i+231 1.1*330 lol+l+l+O

Cut 6 gave a 2 ,l+-dinitrophenylhydrazone with a melt­ ing point and a mixed melting point with the same deriva­ tive of methyl neopentyl ketone of 99.5°.

Cuts 3-7, J+.6.3

g., represent a 35»5$> yield of methyl neopentyl ketone formed by metathesis.

The methyl neopentyl ketone formed

in this reaction was colorless; the usual color of the product obtained by the oxidation of diisobutylene is yellow. The uncertain quality of the starting bromoketone makes the reliability of the amount of metathesis in this reaction doubtful.

This .should be repeated in order to

find the exact amounts of methyl neopentyl ketone and di­ me thylpinacolylcarbinol produced, 1

The action of 10% KOH in methanol on l+,l+-dimethyl-3-bromo2-pent an one _ I In a 5 liter flask fitted with a stirrer, condenser and dropping funnel were placed I7I+O cc. of methanol and


15^4- 6* (2*75 moles) of KOH*

To this solution was added

lj.82 g. (2*5 moles) of lj.,lj.-dimethyl-5-bromo-2-pentanone during 1*5 hours.

After the addition, the solution was

stirred for 5 hours and then heated with rapid stirring for 2*5 hours on the steam bath.

The solution was poured

into 2 liters of water and the oil layer was separated. The water layer was extracted with two 500 cc. portions of ether; the ether extracts were combined with the oil which was originally separated and the ether was removed on the steam bath.

The residue was dried over KgCO^ and fraction­

ated... through CRE II* Cut


Head T.

The amide from cut



20 D

was prepared by hydrolyzing the

ester with 20°/o KOH, extracting the acid, treating with SOCI2 t0 mhke the acid chloride and pouring into ammonia


90 The melting point was 106°,


Cuts 9-15, 32.1 g., represent a 2k. 9,% yield of methyl ne thyl-t-butylacetate. The acrion of 10% BIOS in methanol on 2 ,k-b^mp.t>iyi-?-br>mrn3-pentanone “ ------- ----- ''— —— Tne preparation of L'ne bromoketone has been described in Part 1 of this thesis. m e reaction was done just as described for 4 ,k-dimethyl-3-bromo-2-pentanone except that 1,40 moles of The orcnoketcne and a proportionate amount of the other rea­ gents were used, Cut


He s.cl ‘ i«


1 2

2.1 9 o9 ll.k

55-100° 106 106 107 107.5 lOo 108 108 110 110 110 110


3 k


5.7 13.5 12.5 10.9



6 7 0 10 11 12

13 u

12.4 11.9 11.7 T? ,Q


?n D

l.q-172 l,Ij20l| l.i+210


1 . 1*211 I.ii2l0 1.L211 l.lj.205 l.k200 1.4200 l.k202 1.4200 I.k2k5


The 2,4-dinitrOpiaenylhydrazone 105-106°. The oroduct has not been identified.

Although the

boiling point is almosr one same as m a r 01 one product obtained by hydrolysing the bromoketone with 10% Na2C0j (Part 1 , Sec. C of this thesis), the refractive index and

91 th e very

m e ltin g

p o in t

d iffe re n t.


th e

2 ,lj.-d in itro p h en y lh y d razo n e






) Aston, Clarke, Burgess and Greenburg, J.Am.Chem.Soc. 6Jj., 300 (I9k 2 ) ) Aston and Greenburg, J.Am.Chem.Soc. 62, 3135 (I9I4.O) ' Bartlett, J.Am.Chem.Soc. 57, 22k (1935) Bartlett and Rosenwald, ibid. 56, 1990 (193k) Bert, Compt. rend. 186, 587 (19^ 9 ) Bouveault and Chereau, Compt.rend. lk2 , 1986 (1906) Bygden, Ber. lj£, 3J779 (1912) Caesar and Francis, Ind.Eng.Chem. 1I4.26' (19J4.I) Carothers and Berchet, J.Am.Chem.Soc. 55, 2807 (1933) Carothers and Berchet, ibid. 2813 tl§33) Cline, Ohio State University Thesis (19I1.O) Conant andi;Blatt, J.Am.Chem.Soc. £1., 1227 (1929) P^nehy^ Killian, .apd Nleuwland, J.Am.Chem.Soc. £8, 611 (1936) Dinerstein, Pa. State College Thesis (19I4.O) Edgar, Calingaert and Marker, J.Am.Chem.Soc. £1, lb-83 (1929) Faworsky, J.prakt .chem. 88, 6I4.6 (1^13) Faworsky, i b i d . B E , 6 5 1 ( 1913 ) Faworsky, i b i d . B E , 6 7 9 ( 1913 ) Faworsky, Bull.soc.chim."3 9 » 2l6 (1926) Fisher, Oakwood and Fuson, J.Am.Chem.Soc. 5 2 5036 1939 Fisher, Snyder and Fuson, ibid. Slj., 3665 (1932.) Gomberg and Cone, Ber. ^ 9 , lk6l (190°) Gomberg and Cone, Ber. 2957 (1906) Harriman, Pa. State College Thesis (1939) Houben, Ber. _^6, 3083 (1903) Howk and McElvain, J.Am.Chem.Soc. jj5 , 3372 (1933) Kirrmann, Bull.soc.chim. 988 (1^26) Kohler and Johnstin, Am.Chem. Jour. 35 (1905) Kohler, Stone and Fuson, J.Am.Chem.Soc. k 9 , 3181 (1927) Kohler and Tishler, ibid. ^ij., 159k (1932) Kohler and Tishler, ibid. 57, 217 (1935) Leers, Bull.soc.chim. k 21 (1926) Leers, ibid. 39, ij.23 (1^26 ) Leers, ibid. 32, k 2k (1926) Locquin and Leers, Bull.soc.chim. 35. 933 (192k) Locquin and Leers, ibid. j?9 , k 26 (T926) Locquin and Leers, ibid. £ 9 , k 33 (1926) Lttwenbein and Schuster, Ann. IjJBl, 106 (1930) Marker and Oakwood, J.Am.Chem.Soc. 60, 2598 (193°) Oldham and Ubbelohde, J.Chem.Soc. 2Bl (1938)





93 {A ft

50 51

52 5 55 56

Organic Syntheses, Vol. XIII, 68 (1933) Oumnof.f, Bull.soc.chim. kg, 568 (1 9 2 8 ) Prevost, Bull.soc.chim. kg, 1372 (1 9 3 1 ) Prevost, and Daujat, ibidT k 7 , 588 (1930) Prevost and Richard, ibid. kg, 1368 (1931) Richard, Compt. rend. Ig8, 12k2 (193)4.)' Richard, Bull.soc.chim. g, 286 (1938) Sackur, Compt. rend. 208, 1092 (1938) SpSth, Monatsh. gk, (1913) S t a s , B u l l . soc.c h i m . B e l g . gg, 379 (1 9 2 6 ) Tiffeneau and Tchoubar, Compt.rend. 198, 9I4.I (19314.) Trotman, J.Chem.Soc. 127, 88 (1925) Umnowa, J.Russ.Phys.Chem.Soc. hk, 88l (1913) Umnowa, ibid. JjJj., 1395 (1913) Vavon, Calin and Pouchier, Compt. rend. 208 203 (1939) Werner and Zilkens, Ber. g 6 , 2116 (1 9 0 3 )



W h itm o re, p r i v a t e co m m u n icatio n W h itm o re a n d c o - w o r k e r s , J.A m .C h em .S o c.


W hitm ore

gg, 1136 (1933) and

G eorge,

A m .C h em .S o c.M eetin g ,

Atlantic City, N. J. (19i,l) Whitmore and Houk, J.Am.Chem.Soc. gk, 37lk (1932) Whitmore and Johnstin, ibid., go, 22b5 (1938) Whitmore and Karnatz, ibid., 60, 2636 (1938) Whitmore and Laughlin, ibid., gg, 1,011 (1932) Laughlin, Pa. State College Thesis (1933) 61, W h i t m o r e a n d L a u g h l i n , i b i d . gg, 3732 (1933) 65 W i l k i n s o n , J . C h e m , S o c . 3^57 (1931)

60 61 62 63


(66 (67

(68 (6 9 (7 0

(71 (7 2 (73 (74(76 (77 (78


Bernstein, Pa. State College Thesis (191,0) Carney, Pa. State College Thesis (19kl)' Delacre, Bull.acad.sci.Belg. 20 (1906) Goebel and Marvel, J.Am.Chem.Soc. gg, 1693 (1933) Hass, MeBee and Weber, Ind.Eng.Chem. 27, 1190 (1935) Hass, MeBee and Weber, ibid., 28, 335 (1936) Hass, MeBee and Hatch, ibid., 2g, 1135 (1937) Plomeyer, Pa. State College Thesis (1933) Huston and Agett, J.Org.Chem. 6 , 123 (I9I4-I) Jones, D. M. , Pa. State College Thesis (1939) Noll, Pa. State College Thesis (3.9 5 8 ) Organic Syntheses, Coll. Vol. I, 138 (1938) Popkin, Pa. State College Thesis (1939) Smith, R. K., Pa. State College Thesis (19kl) Strating and Backer, Rec. trav. chim. gg, 903 (1 9 3 6 ) Whitmore and coworkers, J.Am.Chem.Soc. . 6g, 12li (19i,l)



(80 ) Whitmore and co-workers, J.Am.Chem.Soc. /n . d 9kl) (81) ’Whitmore and He.yd, ibid., 60, 2030 (1938) PART III (82) Aston, Clarke, Burgess and Greenburg, J.Am.Chem.Soc. 6ij., 300 (1 9)1? ) (83 Aston and Greenburg, ibid. 62, 2590 (I9I4.O) (8k Burgin, Engs, Groll and Hearne, Ind. Eng. Chem. 21, iip.3 (1959) (85 Butlerov/, Ann. liji)., 15 (I867) (86 D ’Otreppe de Bouvette, Jahresberichtuber die Fortshritte der Chemie, I4J4.I (1882) (87 Faworsky and Bozhowsky, J. Russ. Phys. Chem. Soc. j±6, 1098 (1915) (88 Hass, McBee and Weber, Ind. Eng. Chem. 22, 1190 (1935) (89 Henry, Compt. rend, lij.2 , I4.96 (1906) (90 Hersh and Nelson, J.Am.Chem.Soc. _^8, 1631 (193&) (91 Karnatz, Pa. State College Thesis (1937) (92 Kondakow, J.Russ. Phys.Chem.Soc. 17, 290 (1885) (95 Meyer and Muller, J.Prakt. chem. Eb, 186 (1892) (9k Mouneyrat, Ann. chim.phys. 20, 532 (1900) (95 Pogorshelsky, J. Russ.Phys.Chem.Soc. £6, 1129 (190J+) (96 Rogers and Nelson, J.Am.Chem.Soc. Jjj8, 1027 (193&) (97 Scheschukow, J.Russ.Phys.Chem.Soc., 16, 320 (I08J4.) (98 Weidlein, E. R., communication (99 Whitmore and Fleming, J.Am.Chem.Soc. 55» 3803 (1933) (100 ’Whitmore and Fleming, ibid., 5jz> i|l6l (1933)