Mechanism for the Bromine Cleavage of the Aromatic Silicon-Carbon Bond and Application of the Beta-Silicon Effect to Pyridine and Thiophene Compounds

140 Pages·7.072 MB·English

by  Torkelson, Arnold

PURDUE UNIVERSITY
THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION
Arnold Torkelson________________________
by____________________
MECHANISM FOR THE BROMINE CLEAVAGE OF
AROMATIC SI LI CON-CARBON BOND ______
ENTITLED
and
APPLICATION OF THE BETA-SILICON EFFECT
TO PYRIDINE AND THIOPHENE COMPOUNDS
COMPUTES WITH THE UNIVERSITY REGULATIONS ON GRADUATION THESES
AND IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS
FOR THE DEGREE OF
Doctor of Philosophy
Professor in Charge of Thesis
Head of School or Department
TO THE LIBRARIAN:-----
m
THIS THESIS IS NOT TO BE REGARDED AS CONFIDENTIAL.
FBOFEBSOH 1ST OHABGE
GRAD. SCHOOD FORM 9—3-49—1M

MECHANISM FOR THE BROMINE CLEAVAGE
OF THE AROMATIC SILICON-CARBON BOND
and
APPLICATION OF THE 3ETA-SILIC0N EFFECT
TO PYRIDINE AND THIOPHENE COMPOUNDS
A Thesis
Submitted to the Faculty
of
Purdue University
Arnold Torkelson
In Partial Fulfillment of the
Requirements for the Degree
of
Doctor of Philosophy
August, 1950
ProQuest Number: 27714072
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ACKNOWLEDGMENT
The writer wishes to thank Dr. R. A. Benkeser for
his help and suggestions during the progress of this re­
search. Appreciation is also extended to the members of the
physical and organic chemistry staffs for their aid in
evaluating and interpreting the kinetic data.
The writer wishes to thank the Purdue Research Founda­
tion for financial assistance which made this work possible.
table of contents
Page
ABSTRACT
PART I. THE MECHANISM OF THE BROMINE CLEAVAGE OF THE
AROMATIC CARBON—SILICON BOND.......................................................... i
PART II. APPLICATION OF THE BETA SILICON EFFECT TO
PYRIDINE AND THIOPHENE COMPOUNDS............................................... XV
SURVEY OF ORGANOGERMANIUM COMPOUNDS....................................................... 1
INTRODUCTION............................................................................................... 1
Germanium. ..................................................................................................... I
Germanium Hydrides......................................................... 2
Germanium Halides................................................ 2
Alkylgermane s........................................................................................................ 3
Arylgermanes. ............................................................... 5
Mixed Aryl and Alkylgermanes. ................................................. 8
AlkyIgermanium Halides............................................................................... 9
Arylgermanium Halides....................................................................................... 13
Mixed Aryl and Alkylgermaniuza Halides. ................................. 17
Bi and Polygermanes............................................................................................ 17
Ring Compounds of Germanium.................................................................. 19
Germa n i um-Me t a 1 Compounds....................................................................... 19
German!um-Nitrogen Compounds............................................................... 19
Germanium-Sulfur Compounds......................................................................... 20
Germanium-Oxygen Compounds..................................................................... 21
Heterocyclic Germanes....................................................................................... 24
BIBLIOGRAPHY...................................................................................................................... 25
PART I. MECHANISM OF THE BROMINE CLEAVAGE OF AROMATIC
CARBON-SILICON BONDS.......................................................................................... 28
TABLE OF CONTENTS (Continued)
Page
INTRODUCTION................................................. 28
EXPERIMENTAL......................................................................................................................... 39
Phenyltrimethylsilane....................................................................................... 39
^-Bromophenyltrime thylsilane......................................... 39
2, 5-Dibromothiophene........................................ 40
2-Bromo-5-Trimettiylsilylthiophene................................................... * 41
2-Trimethylsilylthiophene .......................................................................... 42
Action of Bromine on Phenyltrimethylsilane............................... 43
Action of Bromine on JD-Bromophenyltrimethylsilane..... 43
Action of Bromine of 2-Bromo~5-Trimethylsilylthiophene 44
5-Trimethylsilylthiophene Carboxylic Acid................................. 44
Action of Iodine on 2-Trimethylsilylthiophene. . .............. 45
Organosilicon Compounds...................................................................... 45
Iodine. ................................................................................................................... 46
Bromine............................................................................................... 46
Potassium Iodide.................................................................................... 46
Sodium Acetate. ..... ........................... 46
Disodium Phosphate. ...................................... 46
Dioxan................................................................................................................................ 46
Carbon Tetrachloride.......................................................................................... 47
Equipment.............................................................. 47
Experimental Procedure for the Kinetic Runs................. 47
Procedure I ............................ 47
Procedure I I ...................................................................................................... 49
Procedure III. . ........................................................................................... 49
TABLE OF CONTENTS (Continued)
Page
CALCULATIONS......................................................................................................................... 50
DATA AND RESULTS................................................................................. 52
Attempted Cleavage of jD-Nitrophenyltrimethylsilane♦... 59
Attempted Cleavage of jD-Nitrophenyltrimethylsilane.... 60
Attempted Cleavage of o, m and jq-Nitrophenyltrimethy1-
silane .. . ........................................................................................................... 60
Cleavage of Phenyltrimethylsilane in Nitrobenzene 60
Cleavage of Phenyltrimethylsilane in the Presence of
Aluminum Chloride........................................................................................... 61
DISCUSSION.............................................................................................................................. 61
Cleavage of 2-Bromo-5-trimethylsilylthiophene and
2-Chloro-5-trimethyls ilylthiophene............................................ 61
Cleavage of Phenyltrimethylsilane...................................................... 62
Cleavage of £, m, and _p-Nitrophenyltirmethylsilane.... 64
MECHANISM................................................................................................................................ 65
SUMMARY.................................................................................................................. 70
BIBLIOGRAPHY.................................................................................................................. 72
PART II. THE APPLICATION OF THE BETA-SILICON EFFECT TO
PYRIDINE AND THIOPHENE COMPOUNDS.......................................................... 74
INTRODUCTION......................................................................................................................... 74
EXPERIMENTAL........................................................................................................................ 78
2-Bromopyridine........................................................................................................ 78
2 (/? -Bromoethyl ) pyrid ine................................................................................ 79
2 (/? -Chloroethyl)pyridine............................................................................. 80
2(tv -Chloro-n-amyl)pyridine........................................................................ 81
2 (1^-Chloropropyl) pyridine.......................................................................... 82
2 ( V^-Hydroxypr opyl ) pyrid ine........................................................................ 84
TABLE OF CONTENTS (Continued)
Page
2-Amylpyrid ine........................................................................................................... 85
Dimethylchloromethylohlorosilane................ 87
Trimethylchloromethylsilane....................................................................... 87
2-Trimethylsilylpyridine Procedure I .............................. 88
2-Trimethylsilylpyridine Procedure I I ............................................ 89
Action of Base on 2-Trimethylsilylpyridine .............. 90
Action of Bromine on 2-Trimethylsilylpyrid ine...................... 90
2-Trime thylsilylme thylpyrid ine............................................................... 91
Action of Base on 2-Tr ime thylsilylme thylpyrid ine.............. 92
2 { 0 -Trime thylsilylethyl) pyridine....................................................... 93
Procedure 1........................................................................................................... 93
Procedure I I ...................................................................................................... 93
Action of Base on 2(^ -Trimethylsilylethyl)pyridine... 94
2 ( f -Trimethylsilylpropyl ) pyrid ine.................................................... 95
2(u* -Trimethylsilylamyl ) pyrid ine.......................................................... 96
2-Thienyltrimethylsilane............................................................................... 97
2 (^ -Hydroxyethyl) thiophene................................................................... 98
2 -Chloroethyl ) thiophene ........................................................... 98
2 (/3 -Trimethylsilylethyl)thiophene.................................................... 99
2-Chloromethylthiophene......................................................... 100
Procedure 1........................................................................................................... 100
Procedure I I ............................................. 101
2-Trimethylsilylmethylthiophene............................................................ 101
DISCUSSION ............................................................................................................. 102
SUMMARY...................................................................................................................................... 107
BIBLIOGRAPHY........................................................................................................................ 108
LIST OF TABLES
Table Page
1 . Cleavage of 2-chloro-5-trimethylsilylthiophene 52
2. Cleavage of 2-bromo-5-trimethyls ilyl thiophene............... 53
3. Cleavage of 2-bromo-5”trimethylsilylthicphene♦ ..... 53
4. Cleavage of phenyltrimethylsilane............................................... 54
5. Cleavage of phenyltrimethylsilane. ♦ . ................ 54
6 . Cleavage of phenyltrimethylsilane................................. 55
7. Cleavage of phenyltrimethylsilane............................................... 55
8. Cleavage of phenyltrimethylsilane............................................... 56
9. Cleavage of phenyltrimethylsilane............................................... 56
10. Cleavage of phenyltrimethylsilane................................................ 57
11. Cleavage of ja-nitrophenyltrimethylsilane. ..................... 57
12. Cleavage of c>-nitrophenyltrimethylsilane................. 58
13 • Cleavage of m-nitrophenyItrimethylsi 1 ane............................ 58
14. Summary of kinetic data for phenyltrimethylsilane.. 59