Reactions of tosylhydrazones of benzaldehyde and benzophenone with cyanoalkenes in a basic two-phase system

Reaction of tosylhydrazones 1a,b with cyanoalkenes 3a,b, carried out in the presence of concentrated aq. sodium hydroxide in dioxane, afforded either cyanocyclopropanes 5, 9 or pyrazoles 13, 14 and 16, 17. The process takes place via generation of diazocompounds 2a,b from 1a,b their [3+2] cycloaddition to 3a,b with the formation of unstable pyrazolines 4, further fate of which depends on the structure of R1 and R2 substituents.