Studies on quinazoline chemistry. 5. Synthesis of 3,4-dihydroquinazolines with functional substituents at C-2 atom and their alkylation reactions

Syntheses are reported for a new series of 2-substituted 4,4-diphenyl-3,4-dihydroquinazolines by the reaction of o-aminophenyldiphenylcarbinol (APC) with various nitriles. The reaction of APC with substituted 5-bromo-3-cyano-2(1H)-pyridones leads to the formation of derivatives of two products: 3,4-dihydroquinazolines and 4H-3,1-benzoxazines. The alkylation of 3,4-dihydroquinazolines using dimethyl sulfate proceeds through N,N-dimethylation. The structure of these products is a function of the nature of the substituent at C-2 atom of the heterocycle.