THE PREPARATION AND REACTIONS OF SOME l,2-DIPOLAR SPECIES

This research was directed mainly towards the investigation of the reactions of allylic amineimides. The work can be divided into two main sections. Section 1 of the thesis deals mainly with thermolysis studies of amineimides. Sections 1a and 1b represent a comprehensive survey of amineimide literature up to 1971. N-A1ly1-N,N-dirnethylarnine-benzirnide was prepared and rearranged at 1400 to l-allyl-1-benzoyl-2,2-dimethylhydrazine. A tentative mech-anism involving an initial migration to the carbonyl oxygen was disproved by incorporating the amineimide system into a five-membered ring. N,N~Dimethyl-N-propargylamine-benzimidedid not rearrange on heating; but the hydrobromide, on heating, disproportionated to give 1-benzoyl~2,2,2-trimethylhydraziniumbromide and I-benzoyl-2,2~ dimethylhydrazine. l-Ally'l--l, I-dimethyl-2-benzoy-lhydrazinium bromide and 1~benzoy-1-2,2, 2-trimethy-lhydrazinium iodide both disproportionated to give l~benzoyl-2,2-dimethylhydrazine. Section 1 concludes with a discussion of the mechanisms of ally'lic migrations in amineimides proposed by J. E. Baldwin. Section 2 deals with the formation of five-membered hetero-cyclic compounds from amineimides by bromination. 1,1-Dimethyl-2-benzoyl-4-bromopyrazolidinium bromide was formed from N-allyl-N,N-dime thy-lamtne-benz imide, 1,1-dimethyl-2-benzoyl-4-bromopyrazol-3-enium bromide from N,N~dimethyl-N-propargylamine~benzimidevia the.... 3.... unusual acetylenic "bromonium " ion. Hydrogenolysis of both hetero-cyclic compounds gave the same product. The preparation was extended by forming 2,2-dimethyl-4-bromoisoxazolinium bromide from N-allyl-N,N-dimethylamine-N-oxide. Sections 3 and 4 cover a number of unsuccessful attempts to synthesise other amineimides and l,2-dipolar species