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

104 Pages·03.858 MB·English

by  Enyeart, Charles Richard

The Pennsylvania State College
The Graduate School
Department of Chemistry
I. THE SYNTHESIS OF 2,3,3,1+“TETRAMETHYLPENTANE
II. THE SYNTHESIS OF 3,3-DIMETHYL-1-CHLOROBUTANE
III. MISCELLANEOUS
A Thesis
by
Charles Richard Enyeart
i
Submitted in partial fulfillment
of the requirements
for the degree of
Doctor of Philosophy
December 19^-2
December g, , 19^1-2 .. .
AC KN OWLEDGMEN T
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.
i
TABLE OP CONTENTS
Specifications of equipment............... . v
I. THE SYNTHESIS OP 2,3,3,^-TETRAMETHYLPENTANE
Introduction............................................ 1
Historical
A. Preparation of the hydrocarbon by a
Grignard alkylation...... 3
B. Preparation of the hydrocarbon through
the dehydration of methylisopropyl-t-
butylcarbinol........................ ••••• 9
C. Attempted preparation of the hydrocarbon
through the ketone 3,3 ,l|-trimethyl-2-
pentanone . .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-t-
butylcarbinol
Preparation of isopropyl-t-butylcarbinol......37
Preparation of pentamethylacetone........ 38
Preparation of methylisopropyl-t-butyl-
carbinol..................... 40
(a) Reaction of pentamethylacetone
and raethyImagneslum bromide...... 40
(b) MethyImagnesium bromide and
2,[|-dimethyl-2-bromo-3**pentanone. 4l
Dehydration of methylisopropyl-t-butyl-
carbinol ^SO]^)......................42
Hydrogenation of 2,3>5,^“tetramethyl-
1-pentene ....... 44
C. Attempted preparation of the hydrocarbon
through the ketone 3>5 trimethyl-2-
pentanone
Preparation of 2,lp-dimethyl-2-bromo-
3-pentanone...............................4-6
Hydrolysis of 2,i)-dimethyl-2-bromo-3-
pentanone................. .*47
Preparation of trimethylisopropyl
glycol.............. 48
Preparation of 3 »3,ij.-trimethyl-2-
pentanone......... . 30
(a) By the dehydration of tri­
methylisopropyl glycol......... . 50
(b) Attempted-oxidation of methyl-
diisopropylcarbinol..............51
(c) Bromination and attempted re­
arrangement of methyldiisopropyl-
carbinol. ..... 52
Reaction of 3 *3 ,i|.-trimethyl-2-pentanone
in the G-rignard machine...................53
Summary......... 55
Bibliography............... 92
II. THE SYNTHESIS’OF. 3,3-DIMETHYL-1-CHLOROBUTANE
» *
Introduction. • • 5o
•
.
Historical... :.......................57
Discussion....................................... 59
*
Experimental
Preparation of t-butylethylene...... 62
Preparation of 3 >5“^imetkyl“l”bromo1:mtane......6 3
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 69
(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*..... 75
(a) With isoamyl alcohol..................75
(b) With 2-ethylbutanol...................76
(c) With benzyl alcohol... . ..............77
Summary.............................................78
Bibliography........................................ 95
iv
III. MISCELLANEOUS
Discussion................................ 79
Experimental
Preparation of l,2-dichloro-2-methylpropane........ 83
Reaction of methyImagnesium bromide with
1,2-dichloro-2-methylpropane...................... 85
Reaction of ij.,]4.-dimethyl-3“to’omo-2-pentanone
with methylmagnesium bromide...................... 87
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.................. 90
Bibliography................................. 9^
\
I
I
I
V
SPECIFICATIONS OF EQUIPMENT
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
(1932))•
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).
C-IV : 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.
I
PART I
THE SYNTHESIS OP
2,5,3 ,lj.-TETRAMETHYLPENTANE
1
INTRODUCTION
* 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|.-tri-
methyl-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. The
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 thy 1 pen tan e, is also desired in large quantities. How­
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-methyl-
l-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. This reaction was not in­
vestigated in the present work.