This dissertation has been microfilmed exactly as received 68-8871 ROBSON, John Howard, 1940- MIGRATORY ABILITIES OF fi -HETEROATOMIC SUBSTITUENTS TO DIVALENT CARBON. The Ohio State University, Ph.D., 1967 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan MIGRATORY ABILITIES OF p-HETEROATOMIC SUBSTITUENTS TO DIVALENT CARBON DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By John Howard Robson, B.S. ****** The Ohio State University 1967 Approved by Department of Chemistry Dedicated to my wife, Diane ii ACKNOWLEDGMENTS I wish to express my gratitude to Professor Harold Shechter for his inception of this study and for his masterful help in the preparation of this manuscript. Dr. Shechter*s devotion to chemistry and professional character are qualities that have been most inspiring. I am grateful to the Chemistry Department of The Ohio State University, the Department of Navy, the National Institute of Health, and the National Science Poundation for financial assistance. I wish to thank: my parents, wife, and family for their sacrifices, interest and encouragement which enabled my pur­ suit of a formal education. iii VITA July 26, 194-0 Born - East Liberty, Ohio 1962 .................... B.S., Ohio Northern University Ada, Ohio 1962-1964 ............... Teaching Assistant, Department of Chemistry, The Ohio State University, Columbus, Ohio 1964-1967 ............... research Associate, Department of Chemistry, The Ohio State University, Columbus, Ohio iv CONTENTS Page ACKNOWLEDGMENTS iii VITA iv TABLES viii INTRODUCTION 1 HISTORICAL DISCUSSION 18 EXPERIMENTAL 51 General Information 51 Melting points Elemental analyses Infrared spectra Nuclear magnetic resonance spectra Mass spectra Gas chromatography Solvents Intermediates ...................... 53 Methoxyacetonitrile 2-Methoxyacetophenone 2-Methoxyacetophenone tosylhydrazone 2-Phenoxyacetophenone 2-Phenoxyacetophenone tosylhydrazone 2-Hydroxyacetophenone 2-Hydroxyacetoohenone tosylhydrazone 2-Dimethylaminoacetophenone 2-Dimethylaminoacetophenone hydrochloride tosylhydrazone 2-Phenylaminoacetophenone 2-Phenylaminoacetophenone tosylhydrazone 2-Phenylmercaptoacetophenone 2-?henylmereaptoacetophenone tosylhydrazone 2-Ethylmercaptoacetophenone 2-Ethylmercaptoacetophenone tosylhydraz one 2-£thylmerc spto-A1 -chloroacetophenone 2-Ethylmercapto-4-,~chloroacetophenone tosylhydrazone CONTENTS (Cont'd) Page 2-Ethylmercapto-4.,-broEoacetophenone . 61 2-Ethylm9rcaptO“^*-bromoacetophenone tosylhydrazone 2-Kethyl-l,3-dithiane 2-Lithio-2-methyl-l ,3-dithiane 2-Benzoyl-2-methyl-l ,3-dithiane 2-Benzoyl-2-rnethyl-1,3-dithiane tosylhydrazone 2-ForEyl-2-methyl-l ,3-dithisne 2-Forinyl-2-methyl-l ,3-dithiane tosylhydrazone Standards ..... .................. 2-Methoxy-2-phenylethyl iodide a-Methoxystyrene p-M ethoxystyrene cis- and trans-g-Methoxystyrene p-Phenoxystyrene p-Phenylmercaptostyrene p-Ethylmercaptostyrene Decomposition of 2-methoxyacetophenone tosylhydrazone ......... 70 Decomposition of 2-phenoxyacetophenone tosylhydrazone.......................... 74- Decomposition of 2-hydroxyacetophenone tosylhydrazone......................... 76 Decomposition of 2-dimethylaminoaceto- phenone hydrochloride tosylhydrazone .... 77 Decomposition of 2-phenylaminoaceto- phenone tosylhydrazone .................. 79 Decomposition of 2-phenylmercaptoaceto- phenone tosylhydrazone .................. 79 Decomposition of 2-ethylmercaptoacetophenone tosylhydrazone................ 81 Decomposition of 2-ethylmercapto-4-1- chloroacetophenone tosylhydrazone ....... 82 vi CONTENTS (Cont’d) » Page Decomposition of 2-ethylmercapto-4'- bromoacetophenone tosylhydrazone ........... 83 Base-catalyzed thermolysis of 2-pbenyl- mercaptoacetophenone tosylhydrazone in different environments ................. 84 Decomposition of 2-ethylmercaptoaceto- phenone tosylhydrazone by various bases in different environments ........... 85 Reaction of 2-ethylmercaptoacetophenone tosylhydrazone with 3 equivalents of n-butyllithium .......................... 88 Kinetic study of the thermal decomposition of 1-diazo-l-phenylethane................. 91 Kinetic study of the thermal decomposition of l-diazo-2-ethylmercapto- 1-phenylethane ..... ................. 91 Decomposition of 2-benzoyl-2-methyl-l,3- dithiane tosylhydrazone ................... 92 Decomposition of 2-formyl-2-methyl-l,3- dithiane tosylhydrazone ................... 93 APPENDIX I - Infrared Spectra ................ 95 (Figures 1-9) APPENDIX II - Nuclear Magnetic Resonance Spectra . 99 (Figures IO-15) APPENDIX III- Kinetic Plots ...................... 106 (Figures 16-19) vii TABLES Table Page 1. p-Toluenesul fonylhydrazor.es of 2-Substituted Acetophenones ............... 23 2. Base Decomposition of 2-Phenylmercapto- acetophonone Tosylhydrazone............... 86 3. Base-catalyzed Decomposition of 2-Sthyl- mercaptoacetophenone Tosylhydrazone ....... 87 viii INTRODUCTION In the past two decades there has been renewed interest in the chemistry of divalent carbon (l). Such intermediates are known (1) Divalent carbon intermediates in this discussion will be denoted by the general term "carbene." The simplest such inter­ mediate, sCH^ is called methylene; other carbenes are named by adding "-idene" to the name of the corresponding univalent radical. Other members of this homologous series thus are named ethylidene, CH^CH:; benzylidene, PhCH:; etc. [international Union of Pure and Applied Chemistry Report on Nomenclature, J. Am. Chem. Soc.. 82. 5545 (I960)]. as carbenes and contain carbon linked to two adjacent groups by covalent bonds, and possessing two nonbonding electrons which may have antiparallel spins (singlet state) or parallel spins (triplet state). The spin states of carbenes will be discussed in more detail later. The present investigation involves study of intramolecular rearrangement reactions of carbenic systems which allow possible participation of substituents containing electron-donor hetero atoms. The possible participating and rearranging groups of interest are covalent sulfur, oxygen, and nitrogen in positions beta to the divalent center (Equation 1). ? ♦ Z - C - C - -- : - C - C (1) I 1 Z = S, 0. and N, 1 2 The purposes of this study are: 1) to evaluate the migratory abilities of the possible participating hetero groups, 2) to study the effects of environment on the paths of decomposition of such diazo compounds, 3) to use hetero atom rearrangement as a synthetic tool, and 4) to compare the reaction patterns of these carbenic systems with those which occur by appropriately modified mechanisms. The experimental design of this study involves determination of the products of decomposition of selected diazo compounds ob­ tained pure or generated in situ (Equations 2, 3, and 4) by base- catalyzed thermal decompositions of their respective 2~toluenesulfonyl- hydrazones, a process known to proceed via a carbenic mechanism (2). (2) L. Friedman and H. Shechter, J. Am. Chem. Soc., 81, 5512 (1959). n-nhso2c7 h7 n2 :Z~CR2 - C - R - :Z-CR2 - C - R + 02SC?H7 + BH (2) N2 i :Z-CR2 - C - R --- * :Z - CR2 - C - R + K2 (3) :Z - CR2 - C - R --- * :Z - CR* = CR'R + R2C = RC-Z: (4) For determination of the migratory aptitudes appropriate 2-alkylhetero and 2-arylheteroacetophenone tosylhydrazones were 3 prepared and decomposed carbenically. Analysis of the decomposition products is by gas liquid chromatography. Base-catalyzed decomposition of the acetophenone tosyl- hydrazones with sodium methoxide, lithium methoxide, and n-butyl- lithium (1 .0 to 3*1 equivalents) were investigated in order to ascertain the influence of base strength, stoichiometry and various cations upon the carbenic rearrangement processes. A kinetic study of thermolysis of l-diazo-2-ethylmercapto-l- phenylethane and 1-diazo-l-phenylethane was made in order to determine the influence of participation in these decomposition systems. To further extend the study of possible hetero atom rearrangement to carbenic centers, an investigation of base- catalyzed thermal decomposition of l,3"dithiane tosylhydrazones was initiated (Equation 5) . N - NHSOgC^Hy © + N 2 + s o 2 C 7H 7 (5) HISTORICAL Attempts to prepare the simplest carbene, methylene (l), were (1) (a) J. B. Dumas, Ann. chlra. phys., [2], ^8, 28 (1865)* (b) H. V. Regnault, Ibid.[21. 71, -427 (1839). (e) A. Penot, Ann., 101, 375 (1857). (d) A. M. Butlerov, ibid.. 120. 356 (1861). made before the quadrivalency of carbon was established. These early synthetic failures were followed in the first decade of the twentieth century by postulation of carbenes as intermediates in many organic reactions. Methylene was suggested as a reaction intermediate in the photolysis of diazomethane (2) and also in the (2) T. Curtius, A. Darapsky, and E. Kflller, Chem. Ber., £1, 3168 (1908). formation of ethylene by hydrogenation of carbon monoxide over nickel or palladium (3). Early conclusions from work with ketenes (3) E. I. Orlov, Zh. Russk. Fiz. Khim. Obshch., AO, 1588 (1908). and diazo compounds suggested that carbenes are transient diradicals (A), but the observation (5,6) and adequate interpretation (6) of (A) H. Staudinger, E. Anthes, and F. Pfenniger, Ber. deut. chem. Ges., ££, 1928 (1916). A (5) H. Murwein, H. Rathjen, and H. Werner, ibid.. 71* 1610 (1942). (6) W. v. £. Doering, R. G. Buttery, R. G. Laughlin, and N.Chaudhuri, J. Am. Chem. Soc., 78, 3224 (1956). insertion of methylene and other divalent derivatives into carbon— hydrogen bonds made it clear