This dissertation has been microfilmed exactly as received 66—1792 HWANG, Bruce You—Huei, 1936— THE SYNTHESIS OF STABLE NAPHTHOIbjCYCLOBUTADIENES. The Ohio State University, Ph.D., 1965 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan THE SYNTHESIS OF STABLE NAPHTHOCb]GYCLOBUTADIENES DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Bruce You-Huei Hwang, B. S., K, A. ********** The Ohio State University 196? Approved by in -1 Adviser Department of Chemistry ACKNOWLEDGMENTS The author wishes to express his deepest appreciation to Dr. Michael P. Cava, for his advice, guidance and encour­ agement throughout this research. Thanlcs are due to Dr. M. J . Mitchell for his help and to the author's colleagues for their cooperation and for bearing the brunt of his chemical dialectic while this work was in progress. The author also owes a debt of gratitude to Dr. and Mrs. P. Y. Yeh, who kindly furnished him with a home-like enviroment at a time of need. Lastly the author wishes to thank his parents, who contributed greatly to the completion of this work. 11 i VITA January 6, 193& .... Born - TaiwanCFormosa) July, 1958 ........ B. S., The National Taiv/an University Taipei, TaiwanCFormesa) August, 1961 ...... H. A., East Tennessee State University Johnson City, Tennessee Major Field of Study: Organic Chemistry iii CONTENTS Page I INTRODUCTION ................................ 1 II STATEMENT OF PR0BLEI4 ......................... 10 III DISCUSSION AND INTERPRETATION OF RESULTS ... I3 IV EXPERIMENTAL ................................ ^5 a 5 a’-Bis(phenylethynyl)-o-xylene-a,a '- diol (3*+) • • ^5 1.2-Dimethoxy-1,2-diphenylnaphtho[bi­ cycle butene (2 8) ........................ 46 1.2-Dichloro-1,2-diphenylnaphtho[b]- cyclobutene (2 9 ) ........ 4-7 Hethanolysis of 1,2-Dichloro-1,2-di- phenylnaphtho[b]cyclobutene C 2 9 ) to 1 ,2-Dimethoxy-1 ,2-diphenylnaphtho- [b] cyclobutene (2 8) ...................... 4-7 Oxidation of 1,2-Dimetlioxy-1,2-diphenyl­ naphtho [b] cyclobutene (2 8) to 2,3- Dibenzoylnaphthalene (4-7) ............... 4-8 Catalytic Reduction of 1 ,2-Dicliloro-1,2- diphenylnaphtho [b] cyclobutene (2 9 ) to cis-1,2-DiphenylnaphthoCb]cyclo­ butene (49a) ........ 4-8 Pyrolysis of 1,2-Dimethoxy-1,2-di­ phenylnaphtho [b]cyclobutene (28) to 5-Methoxy-12-phenylnaphthacene (53) ..... 4-9 IV CONTENTS (Conta.) Page Pyrolysis of 1,2-Dic}iloro-'l ,2-diphenyl­ naphtho [b] cyclobutene (2 9 ) to 5“ Chloro-12-phenylnaphthacene (55) .......... 50 Thermal Rearrangement of cis-1 ^2-Diphenyl- naphtho[b]cyclobutene (49a) to 5-phenyl- 5,12-dihydronaphthacene (56) .............. 50 Isomerization of cis-1,2-Diphenylnaphtho- [b]cyclobutene (49a) to tran^-1,2-Di- phenylnaphthoCb] cyclobutene (49b) ......... 50 N,1,4-Triphenyl-1,2,3,4-tetrahydro-2,3- antliracene-dicarboximide (59); cis- 1,2-Diphenylnaphtho[b]cyclo­ butene (49a) and N-Phenyl- maleimide Adduct ......................... 51 1,3-Diphenyl-1,3-dihydronaphtho[2,3~c] thiophene 2,2-dioxide (5#) ................ 52 Photolysis of 1,3-Diphenyl-1,3-aihydro- naphtho[2,3-c]thiophene 2,2-dioxide (58) .... 52 to trans-1,2-Diphenylnaphtho[b]- cyclobutene (49b) ............... 52 Aromatization of 5-Phenyl-5,12-dihydro- naphthacene (56) to 5-Phenyl- naphthacene (60) .................. 53 V . CONTENTS (Contdo) Page Synthesis of 5-Phenylnaphthacene (60) ....... 53 T,2-Diphenylnaphtho[b]cyclebutadiene (30) .... 5^ 1.2-Diphenylnaphtho[b]cyclebutadiene (30) and 2,^-,7-Trinitrefluorenene Complex...... 55 1.2-Dibreme-1,2-diphenylnaphtho[bi­ cycle butene (65) .................. 5& Oxidation of 1,2-Diphenylnaphtho[b]cyclo- butadiene (3 0 ) to 2,3-Dibenzoyl- naphthalene (4?) ......................... 56 Hydrogenation of 1,2-Diphenylnaphtho[bi­ cycle butadiene (30) to cis-1,2-Di- phenylnaphtho[blcyclobutene (49a) ......... 57 5j 5a,11b,12-Tetrahydro-5,5a, 11b,12-tetraphenyl- 5,12-epoxydibenzo[b,hlbiphenylene (66); Adduct of 1,2-Diphenylnaphtho[bicycle- butadiene (30) and 1,4-Diphenyl-2,3- benzofuran (14) .......................... 57 Preparation of 3,8-Diphenylnaphtho[bl- cyclobutene (21) ......................... 58 1 -Bromo-3,8-diphenylnaphtho[blcyclo­ butene (71) .............................. 59 trans-1,2-Dibromo-3,8-diphenylnaphtho[bl- cyclobutene (22b) .................... 60 VI CONTENTS (Contd.) Page 1,1-Dibromo-3,8-diphenylnaphtho[b]- cyclobutene (7 2) .......................... 60 1,1,2,2-Tetrabromo-3,8-diphonyl- naphtho [b] cyclobutene (3 1) ................ 61 Hydrolysis of 1-Bromo-3,8-diphenylnaphtho- [b]cyclobutene (71) to 1-Hydroxy-3?8-di- phenylnaphtho [b] cyclobutene (73) .......... 62 Hydrolysis of 1,1-Dibromo-3>8-diphenyl­ naphtho [b] cyclobutene (72) to 3,8-Di- phenylnaphtho[b]cyclobuten-1-one (7^) ...... 62 Oxidation of 1-Hydroxy-3,8-diphenyInaphtho- [b]cyclobutene (73) to 3,8-Diphenyl- naphthoLb]cyclobuten-1-one (743 ........... 63 Hydrolysis of 1,2-Dibromo-3)8-diphenyl­ naphtho [b] cyclobutene (22) to 1,2-Di- hydroxy-3,8-diphenylnaphtho[b]cyclo­ butene (75) .............................. 64 Hydrolysis of 1,1,2,2-Tetrabromo-3?8- diphenylnaphthoCb]cyclobutene (3 1) to 3,8-Diphenylnaphtho[b]cyclo­ butene 1 ,2-dione ( 76) .................... 64 Reduction of 3,8-Diphenylnaphtho[b]cyclo­ butene 1,2-dione (76) with Sodium Boro- hydride to 1,2-Dihydroxy-3,8-dlphenyl- naphtho[b]cyclobutene (75) ......... 65 vii CONTENTS (Gontd.) Page Attempted Synthesi's of 3,8-Diphenyl- naphthoCb]cyclebutadiene (17) ............. 66 Trapping of 3,8-Diphenylnaphtho[b]cyclo- butadiene (17) with 1,^-Diphenyl-2,3- benzofuran (140 ........................ 66 Attempted Synthesis of 1-Bromo-3,8-diphenyl­ naphtho Cb] cyclobutadiene (77) ............. 67 Trapping of 1-Bromo-3,8-diphenylnaphtho[b]- 4' cyclobutadiene (77) with 1,4-Diphenyl- 2,3-benzofuran (14) ...................... 67 1.2-Dibromo-3,8-diphenylnaphtho[b]- cyclobutadiene (3 2) ...................... 68 Addition of Bromine to 1,2-Dibromo-3,8-di- phenylnaphtho[b] cyclobutene (3 2) .... 69 1.2-Dibromo-3,8-diphenylnaphtho[b]cyclo­ butadiene (3 2) and 1,4-Diphenyl-2,3- benzofuran Adduct; 5a,1 lb-Dibromo- 5,6,11 ,12-tetraphenyl-5,5 a, 11b, 12- tetrahydro-5 ,12-epoxydibenzo[b,h]- biphenylene (7 9) .................... 70 Reaction of 1,2-Dibromo-3,8-diphenyl­ naphtho [b] cyclobutadiene (3 2) with Sodium Methoxide ........... 70 viii CONTENTS (Gontd.) Page 2-Bromo-3,8-diphenylnaphtho[b]- cyclobuten-1-one (80) .................... 70 2-Hydroxy-3)8-diphenylnaphtho[b]- cyclobuten-1-one (8l) .................... 71 APPENDIX I ULTRAVIOLET ABSORPTION SPECTRA ....... 72 APPENDIX II NUCLEAR MAG^IETIC RESONANCE SPECTRA 8l APPENDIX III INFRARED ABSORPTION SPECTRA .......... 90 IX I. INTRODUCTION For years, the chemistry of cyclobutadiene, benzocyclo- butadione, naphthocyclobutadiene and their derivatives has held the interest of many organic chemists. Until the start of this work, all isolable compounds containing a cyclo­ butadiene nucleus have been either stabilized as their tran­ sition metal complexes or fused on both side as in biphenyl­ ene, to aromatic systems. Among those cyclobutadiene derivatives, which are stabilized by fusion on both sides to aromatic rings, are biphenylene (1) and dibenzobiphenylenes. Biphenylene (1) •1 was first synthesized by Lothrop and 2,3,6,7-dibenzobi- p 3 1-1 phenylene (2) by Curtis and Viswanath.Cava and 8tucker ^ W. C. Lothrop, J. Am. Chem. Soc., 6^ 1l8? (19^1). p R. F. Curtis and G. Viswanath, Chem. and Ind., 117^ (19540. R. F. Curtis and G. Viswanath, J. Chem. Soc., 1670 (1959). ^ M. P. Cava and J. F. Stacker, J. Am. Chem. Soc., 22 6022 (1955). synthesized 1 ,2-benzobiphenylene (3) and 1,2,7,8-dibenzobi- phenylene (4), and pointed out that 2,3,6,7-dibenzobiphenyl- ene (2) is thermally more stable than 1,2,7,8-dibenzobi- phenylene (4). The stability of these compounds has also been discussed from the theoretical point of view by Ali and Coulson;^ from molecular orbital calculation of their pi- electron energies and bond orders, it was found that the resonance energy of ■2,3,6,7-dibenzobiphenylene (2) exceeds that of 1 ,2,758~dibenzcbiphenylene (4-) by ^.3 kcal/mol.. (1) (3) (W M. A. Ali and C. A. Coulson, Tetrahedron, 1_0 U-1 (I960). Another group of stabilized cyclobutadiene derivatives are the cyclobutadiene transition metal complexes; examples of the latter include 1,2,3,^--tetramethylcyclobutadiene 6 7 nickel bromide complex,’ 1,2,3,^-tetraphenylcyclobutadiene nickel bromide complex,8 1,2,3,4-tetraphenylcyclobutadiene ^ R. Criegee and D. Schroeder, Ann., 623 1 (1959)* ^ R. Criegee, Angew. Chem., 2h. 703 (1962). ^ H. H. Freedman, J. Am. Chem. Soc., 82 219^ (1961). Q -IQ iron carbonyl complex or palladium chloride complex, and the recently discovered benzocyclobutadiene iron tricarbonyl / "j 4 complex (5) etc. These complexes form a group of compounds in which the bonding between the metal and the carbocycle has considerable pi-character. 0 JJ--Fe(C0)3 (5) (6) (7) ^ W, Huebel, et al., J . Inorg. Nucl. Chem., 2 20*+ (1959). T. Blomquist and P. M. Maitlis, J. Am. Chem. Soc., ^ 2329 (1962). 1 1G. F. Emerson, L. Watts and R. Pettit, J. An. Chem. Soc., ^ 131 (1965). A group of stable compounds which may be considered to be closely related to cyclobutadiene are the cyclobutadieno- 12 quinones, such as phenylcyclobutadienoquinone (6 ) and 1 3 benzocyclobutadienoquinone (7), in which all four-membered ring carbons are sp^-hybridized. 12 E. J. Smutny, M. C. Caserio and J. D. Roberts, J. Am. Chem. Soc., ^ 1793 (I960). 1 3 M. P. Cava