Quinazoline studies. Part XII. Action of acid and alkali on quinazoline

Abstract

Quinazoline was converted into 2-aminobenzaldehyde and its anhydro-polymers (the trimer, the tetramer, and the monoformyl-tetramer) by the action of hot dilute acid or alkali. The substance of high-molecular weight formed from quinazoline below pH 1·5 was found to be a polymer of the 3,4-adduct of the latter with 2-aminobenzaldehyde. The anhydro-dimer of 2-methylaminobenzaldehyde and the dimer of 2-aminobenzaldehyde methyl imide were found, on the evidence of the i.r., u.v., and n.m.r. spectra, to be 6,12-epoxy-5,11-dimethyldibenzo[b,f][1,5]diazocine (Va) and 6,12-methylimino-5H,11H-dibenzo[b,f][1,5]diazocine (Vc).