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ZEEB ROAD, ANN ARBOR, Ml 48106 18 BEDFORD ROW, LONDON WC1R 4EJ, ENGLAND V. h I 8001791 - NAIR, MRIDULA PART I: THE CHEMISTRY OF 2-DIAZOIMIDAZOLE AND 2H- IMIDAZOLYLIDENE, PART II: REARRANGEMENTS OF 1-(5-OXAZOLYL)• 1-ALKYLIDENES. PART III: A NEW McFADYEN-STEVENS ALDEHYDE METHOD The Ohio State University Ph.D. 1979 University Microfilms I n te r n ât i0 n â I 300 n . Zeeb Road, Ann Arbor, M I 48106 18 Bedford Row, London W C IR 4EJ, England PART I: THE CHEMISTRY OF 2-DIAZOIMIDAZOLE AND 2H-IMIDAZ0LYLIDENE PART II: REARRANGEMENTS OF 1-(5-OXAZOLYL)-1- ALKYLIDENES PART III: A NEW McFADYEN-STEVENS ALDEHYDE METHOD DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Mridula Nair, B. Sc., M. Sc. ***** The Ohio State University 1979 Reading Committee: Approved By Professor Jack Hine Professor John A. Secrist III Professor Harold Shechter AdvisorIdvisor Department of Chemistry This work is gratefully dedicated to my parents for their selfless love and commitment. ii ACKNOWLEDGMENTS I wish to express my debt and my deep sense of gratitude to Professor Harold Shechter for his inspiring guidance and unstinted help. Professor Shechter's constant encouragement, patience, and understanding are truly invaluable and shall never be forgotten. I would also like to extend my gratitude to The Ohio State University, the National Science Foundation, and the National Institutes of Health for their financial support. Finally, I gratefully acknowledge the cooperation of Ms. Bobbie Cassity in typing this manuscript. iii VITA November 11, 1953 Born - Kerala, India 1973 ............ B.Sc., Madras University, Madras, India 1975 ............. M.Sc., Indian Institute of Technology, Madras, India 1975-1977........ Teaching Associate, Department of Chemistry, The Ohio State University, Columbus, Ohio 1977-1979, Research Associate, Department of Chemistry, The Ohio State University, Columbus, Ohio PUBLICATIONS "Vacuum Pyrolysis of Salts of l-Acyl-2-arylsulphonyl- hydraziines; a General McFadyen-Stevens Aldehyde Synthesis." M. Nair and H. Shechter, Chem. Commun., 793 (1978). "A Convenient Synthesis of 6H-[l]Benzopyrano[4,3-b]- quinolines," K.K. Balasubramanian, G.V. Bindumadhavan, M. Nair, and B. Venugopalan, Synthesis, 511 (1977). "Thermal Rearrangement of 4-Chloro-3-aryloxymethyl-3- chromenes," K.K. Balasubramanian, M. Nair, C. Devakumar, and B. Venugopalan, Chemistrv and Industry, 611 (1976). IV TABLE OP CONTENTS Page DEDICATION................. il ACKNOWLEDGMENTS................................... ill VITA ............................................. iv LIST OF TABLES AND FIGURES........................ vii PART I: THE CHEMISTRY OF 2-DIAZOIMIDAZOLE AND 2H-IMIDAZ0LYLIDENE ...................... 1 STATEMENT OF PROBLEM ............ 2 HISTORICAL .............................. 3 RESULTS AND DISCUSSION ................. 23 EXPERIMENTAL .............. 81 PART II: REARRANGEMENTS OF 1-(5-OXAZOLYL)-1- ALKYLIDENES.............................. 115 STATEMENT OF PROBLEM ................... 116 HISTORICAL .............................. 117 RESULTS AND DISCUSSION ................. 125 EXPERIMENTAL............................ 139 PART III: A NEW McFADYEN-STEVENS ALDEHYDE METHOD 161 STATEMENT OF PROBLEM ................... 162 HISTORICAL................. 163 RESULTS AND DISCUSSION ................. 167 EXPERIMENTAL ............................ 177 V CONTENTS (CONT'D) Page REFERENCES Part I ....................................... 191 Part I I ..................................... 196 Part I I I ..................................... 198 VI LIST OF TABLES Table Page 1 Decompositions of Sodium Salts 33a-c . 130 2 Pyrolysis of Sodium Salts 33a-c at 350°C 135 3 Aldehydes by the Present McFadyen-Stevens M e t h o d ................................ 170- 4 Decomposition of Sodium and Lithium Salts of l-Acyl-2-p-tosylhydrazides 186. LIST OF FIGURES Figure 1 Vacuum Pyrolysis Apparatus ............... 185 vii PART I The Chemistry of 2-Diazoimidazole and 2H-Imidazolylidene STATEMENT OP THE PROBLEM The present study involves investigation of the chemistry of 2-diazoimidazole (^) and 2H-imidazolylidene (2), the carbene derived from The principal objectives of this research are: (1) to study the thermal and C > O : photo lytic reactions of and/or 2 with a variety of substrates such as hydrocarbons, olefins, amines, ethers, alcohols, benzenes, and heterocyclic aromatics; (2) to explore the possibilities of preparing molecules with new and unusual structures that may be of synthetic value; and (3) to determine the mechanistic features underlying the reactions of 1 and of 2. HISTORICAL The chemistry of diazocyclopentadiene (3_), its aza- analogS/ and their related car bene s has been of interest because of the fascinating reactions they undergo. The unusual aspects of some of these transformations have drawn certain attention; however, detailed mechanistic insight with respect to most of these processes is lacking. In this section which is intended to be illustrative rather than exhaustive, some representative examples of these reactions will be examined. = 9 ^ = N 3 4 Diazocyclopentadiene (^), first reported in 1953,^ has been important to the theory of organic chemistry because it is a stable 6 Il-electron Hückel system (4). Cyclopentadienylidene (5_), ,derivable from ^-4 by pyrolysis or photolysis, is a carbene of interest as a singlet (5a) (1) W. von E. Doering and C.H. DePuy, J. Am. Chem. Soc., 75, 5955 (1953). 0 - - 5a 5b and as a triplet ( ^ ) . Calculations indicate that ^ is a stabilized, electrophilic, 611 electron carbene (5^). BSR studies^ however, establish that 5 is a triplet in its ground state (5b). (2) R. Gleiter and R. Hoffmann, J. Am. Chem. Soc., 90, 5457 (1968). (3) E. Wasserman, L. Barash, A.M. Trozzolo, R.W. Muwayand, and W.A. Yager, J. Am. Chem. Soc., 86, 2304 (1964). Olefins undergo stereospecific addition of ^ and thus the reactant is presumed to be the singlet 5a (Eq. 1).^ 5 (1) 98% 5 100% Further, the reactivities of p-substituted styrenes (Eq. 2) to give a linear free energy correlation with a kinetic p 5a + CH=CH, (2) value of -0.76 and cr substituent constants reveal the electrophilic character of 5a.^ (4a) R.A. Moss, J. Ora. Chem.. 31, 3296 (1966) ; (b) R.A.Moss and J.R. Przybyla, ibid., 3 3,‘ 38lS^(1968). (5) H. Durr and F. Werndorf, Angew. Chem. Int. Edn., 13, 483 (1974). Photolyses of substituted diazocyclopentadienes (6) in benzene and its derivatives give spironorcaradienes (7_) in equilibrium with spirocycloheptatrienes (8).^ Thermal (6a) H. Durr and H. Kober, Angew. Chem. Int. Edn., 10, 342 (1971); (b) H. Durr and H. Kober, Tetrahddron LettT, 1259 (1972); (c) H. Durr, H. Kober, V. Fuchs, and P. Orter, Chem. Comm.. 973 (1972); (d) M. Jones, Jr., A.M. Harrison, and K.R. Pettig, J. Am. Chem. Soc., 91. 7462 (1969); (e) D. Schonleber, Chem. Ber., 102,"xT89 (1969). R R 8 rearrangement of 7-8 yields 9, the overall product of aromatic substitution (Scheme 1). Photochemical rearrange­ ment of the equilibrium mixtures of 7 and 8 results in I,7-migration or di-IT-methane rearrangement to form and 7 II. Diazocyclopentadienes 12 unsubstituted in their SCHEME 1 di-II-methane 9 ^ [1,5] 4-positions, irradiate in benzene to give bicyclo[6.3.0]- Q undecapentaenes (^, Eq. 4). The above reactions of ^ and substituted cyclopentadienylidenes with benzene appear 1 hv N 2 12 (4) R H 13 to involve singlet intermolecular processes rather than intersystem crossing to tripet states. (7) H. Durr, H. Kober, I. Holberstadt, U. Neu, T.T. Coburn, T. Mitsuhashi, and W.M. Jones, J. Am. Chem. Soc.,

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