ADDITION-PRODUCTS OF HYDRAZINE DERIVATIVES TO AZO-ALKENES .5. THE REACTION OF ALPHA-(1-PHENYLHYDRAZINO)ALKANONE PHENYLHYDRAZONES WITH ACIDS AND ACID-DERIVATIVES

The bifunctional title compounds 2 react with acylating, carbamoylating and sulfonylating reagents mostly at the primary amino group of the hydrazine function. Both functional groups of 2 are attacked by N,N'-carbonyldiimidazole converting it into 1H-1,2,4,5-tetrazepin-3-one derivatives 8. The acid-induced 1,4-elimination of phenylhydrazine from 2 gives rise to the formation of phenylosazones 3. In the presence of thiocyanic acid the intermediately formed phenylazo-alkenes 1 undergo [3 + 2]-cycloaddition furnishing 1-anilino-imidazoline-2-thiones 13.