Studies on the Synthesis of Pyridazine Derivatives. X. Reaction of 3, 6-Dimethoxy-4-nitropyridazine 1-Oxide with Alkyl Halides

Abstract

Reaction of 3, 6-dimethoxy-4-nitropyridazine 1-oxide (I) with alkyl halides were investigated, and following results were obtained. 1) Reaction with methyl iodide gave 1, 3, 4-trimethoxy-6 (1H) pyridazinone (II). 2) Reaction with ethyl iodide gave 1, 4-diethoxy-3-methoxy-6 (1H) pyridazinone (IV). 3) Reaction with ethyl chlorocarbonate gave 1-ethoxycarbonyloxy-3-methoxy-4-chloro-(VI) and 1, 4-bisethoxycarbonyloxy-3-methoxy-6 (1H) pyridazinone (VII). 4) Reaction with ethyl bromoacetate gave 1, 4-bisethoxycarbonylmethoxy-3-methoxy-6 (1H) pyridazinone (IX). Moreover the reaction of 4-nitropyridazine 1-oxide derivatives with methyl iodide was described. 1) Reaction with 3-methoxy-4-nitro-6-methylpyridazine 1-oxide (XIII) gave 3, 4-dimethoxy-6-cyanopyridazine 1-oxide (XV) and 1-methyl-3-methoxy-6-cyano-4 (1H) pyridazinone (XVI). 2) Reaction with 6-methoxy-4-nitropyridazine 1-oxide (XIV) gave 1, 4-dimethoxy-6 (1H) pyridazinone (XX).