Studies on pyrimidine derivatives. XXXIX. Site-selectivity in the reaction of 5-substituted and 4,5-disubstituted pyrimidine N-oxides with trimethylsilyl cyanide.

Abstract

The site-selectivity in the modified Reissert-Henze reaction of 5-substituted, and 4, 5-disubstituted pyrimidine 1-oxides with trimethylsilyl cyanide was examined. The reaction of 5-substituted 4-methoxypyrimidine 1-oxides with trimethylsilyl cyanide gave exclusively 2-pyrimidine-carbonitriles in good yields without exception. On the other hand, the other 5-substituted and 4, 5-disubstituted pyrimidine 1-oxides gave mainly 6-pyrimidinecarbonitriles.