Ketenimines as intermediates to heterocycles. Part 2. 2-Phenylimino-3,4,5-triphenyl-1,3-oxazoline
Abstract
The reaction product C27H20N2O from benzoylphenylacetaldehyde and N-phenylhydroxylamine has been identified as 2-phenylimino-3,4,5-triphenyloxazoline (4) on the basis of acid hydrolysis to 3,4,5-triphenyloxazolin-2-one (5), alkaline hydrolysis to N-desyl-NN′-diphenylurea (6), and catalytic hydrogenation to N-(1-phenylstyryl)-NN′-diphenylurea (9) and N-(1,2-diphenylethyl)-NN′-diphenylurea (10). A reaction mechanism is proposed, which accounts for the formation of the imino-oxazoline (4) by reaction of N-phenylhydroxylamine with the intermediate C-benzoyl-CN-diphenylketenimine (3).