Nitroimidazoles. V. Synthesis of 1‐methyl‐2‐(2‐methyl‐4‐thiazolyl)nitroimidazoles

Reaction of readily available 2‐methyl‐4‐formylthiazole (1) with glyoxal and ammonia gave 2‐(2‐methyl‐4‐thiazolyl)imidazole (2). Nitration of 2 with a mixture of nitric acid‐sulfuric acid at 100° yielded 2‐(2‐methyl‐4‐thiazolyl)‐4,5‐dinitroimidazole (3) as the sole reaction product, while nitration at 65° afforded 2‐(2‐methyl‐4‐thiazolyl)‐4‐(or 5)‐nitroimidazole (4). N‐Methylation of compound 4 in the presence of base gave 1‐methyl‐2‐(2‐methyl‐4‐thiazolyl)4‐nitroimidazole (6), whereas N‐methylation with diazomethane afforded 1‐methyl‐2‐(2‐methyl‐4‐thiazolyl)‐5‐nitroimidazole (5). N‐Methylation of compound 3 yielded 1‐methyl‐2‐(2‐methyl‐4‐thiazolyl)‐3,5‐dinitroimidazole (7) in high yield.