Syntheses and reactions of some 2,3‐disubstituted pyrazine monoxides

The reactions of 2,3-dimethyl- (4), 2,3-diphenyl- (6), and 2-methyl-3-phenyl-pyrazine monoxides (8 and 9) with phosphoryl chloride and acetic anhydride resulted in giving monochloro- and monacetoxy-pyrazines in almost all cases. However, the reaction of 6 with acetic anhydride afforded exceptionally a diacetoxydihydro-pyrazine. These products were converted further to hydroxy or dichloro derivatives.