Polyhalogenoheterocyclic compounds. Part XXVII. Nucleophilic substitution in chlorofluoropyrazines and tetrachloropyrazine
Abstract
Substitutions in tetrachloropyrazine by dimethylamine, hydrazine, and methoxide are described. The orientation of further substitution in the resulting trichloropyrazines is established by independent syntheses from known chlorofluoropyrazines. In the absence of dominating steric effects, nucleophilic attack ortho to the substituent in trichloropyrazines is preferred.