Nuclear chlorination of alkylpyrazines

Abstract

A series of monoalkylpyrazines have been chlorinated specifically in the 3-position with sulphuryl chloride in the presence of NN-dimethylformamide; the nucleus of symmetrical 2,6-dialkylpyrazines is also readily chlorinated. The structures of the by-products from some of the reactions have been assigned. The reaction of isobutylpyrazine with phosphoryl chloride and phosphorus pentachloride was also investigated and gave specifically 2-chloro-5-isobutylpyrazine in 25% yield.