The condensation of N-phenyl-W-(2-hydroxylphenyl)urea orN-phenyl- N '-(2-aminophenyl)urea with tris(dialkylamino)phosphine afforded derivatives of 4, 5-benzo-l, 3, 2-oxaza (or diaza)-phospholane which formed intramolecular hydrogen bond. The cleavage of the amide bond to give N, N-dialkyl-N'-phenylurea together with polymers of 1, 3, 2-benzodiazaphosphole was observed in the latter reaction. © 1990,...
