Reactions of quinazoline and its 4-oxo- and 4-chloro-substituted derivatives with nucleophiles

Reaction of quinazoline ( I ) with 2-methylindole, pyrogallol, and 1-phenyl-3-methylpyrazol-5-one in the presence of acid led to the formation of C-4 adducts II , III , and V . Adduct IV was obtained by heating I with 1,3-dimethylbarbituric acid without acid catalysis. 1-Phenyl-3-methylpyrazol-5-one reacts with I without acid catalysis with the formation of dipyrazolylmethane VI . 4-Chloroquinazoline VIII reacts with 1-phenyl-3-methylpyrazol-5-one to yield 4-(1-phenyl-3-methyl-5-oxopyrazol-4-yl)quinazoline IX and dipyrazolylmethane VI . Heating VIII with 2-methylindole leads to formation of 4-(2-methylindol-3-yl)quinazoline X and tris(2-methylindol-3-yl)methane XI . The proposed structures were confirmed by NMR spectral data.