Reactions of halogenomethanes in the vapour phase. Part 3. Reactions of chloroform with pyrazoles, indazole, and other heterocycles at 555 °C

Abstract

A mixture of chloroform and either pyrazole (1) or a C-methylpyrazole [(2)–(6)] in a continuous-flow vapour-phase reactor at 555 °C gives a high yield (51–89%) of a 2-chloropyrimidine [(7)–(12)] as the only product. Indazole (13) similarly gives only 2-chloroquinazoline (14). These results contrast with the known formation of mixtures of products from the corresponding pyrroles and indoles, and the present finding that a number of heterocycles which do not contain the NH group give only carbon under similar conditions.