Synthesis of pyrimidines from ketones using microwave irradiation
A simple, high yielding synthesis of pyrimidines from ketones in the presence of HMDS and formamide is described. Under microwave irradiation, heteroaromatic, aryl, aliphatic, and cyclic ketones cyclized to give pyrimidines in good yields.
Studies on Pyrimidine Derivatives. XXXIX. Site-Selectivity in the Reaction of 5-Substituted and 4,5-Disubstituted Pyrimidine N-Oxides with Trimethylsilyl Cynanide
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-pyrimidinecarbonitriles in good yields without exception.On the other hand, the other 5-substituted and 4,5-disubstituted pyrimidine 1-oxides gave mainly 6-pyrimidinecarbonitriles.Keywords--site-selectivity; pyrimidine N-oxide; trimethylsilyl cyanide; Reissert-Henze reasction; pyrimidinecarbonitrile