Synthesis of New Pyrimidine Derivatives from 2-Methyl-3-nitro- and 3-Amino-2-methylchromones

Reactions of 2-methyl-3-nitrochromone (1) with guanidine, acetamidine and benzamidine readily gave the corresponding 2-substituted-6-(2-hydroxyphenyl)-4-methyl-5-nitropyrimidine (3a-c) in good yields, and these were converted to 6-(2-methoxyphenyl) pyrimidines (4a-c) by treatment with methyl iodide and to 5-aminopyrimidines (5a-c) by catalytic hydrogenation. 3-Amino-2-methylchromone (2) reacted with guanidine, but not amidines, to give 2, 5-diamino-6-(2-hydroxyphenyl)-4-methylpyrimidine (5a). 3-Acetamido-2-methylchromone (6) was converted more readily than 2 into pyrimidine derivatives (7a, c) by the reactions with guanidine and benzamidine, respectively.