Synthesis of Novel Quinazoline Derivatives via Pyrimidine ortho-Quinodimethane

The [4+2] cycloaddition between 2,4-diphenylpyrimidine ortho-quinodimethane and dimethyl acetylenedicarboxylate leads to 2,4-diphenylquinazoline-6,7-dicarboxylate (6). 2,4-Diphenylfuro[3,4-g]quinazoline-6,8-dione (7) is also obtained by basic hydrolysis of compound 6, followed by the closure of the resulting diacid in acetic anhydride.