Benzimidazole誘導体の合成研究 (第2報)
N-Substituted 2-Methyl-5(or 6)-benzimidazolesulfonamide類について
1962 年 82 巻 4 号 p. 469-474
詳細
1962 年 82 巻 4 号 p. 469-474
1) Synthetic process for 3-nitro-4-acetamidobenzenesulfonyl chloride (VIII) was examined and it was found that the o-nitrophenylurethan method is better than ethyl o-nitrophenyloxamate method described in literature. Nitration of p-acetamido-benzenesulfonyl chloride results in poor yield of (VIII) if the period of nitration is extended and 4-amino-3, 5-dinitrobenzenesulfonyl chloride is formed if the reaction mixture is left over night.
2) N-Substituted 3-nitro-4-acetamidobenzenesulfonamides (Table I) were prepared by application of 16 kinds of primary amines and 10 kinds of secondary amines to (VIII). These sulfonamides were derived to N-substituted 2-methyl-5(or6)-benzimidazoles (Table II) by application of reductive cyclization with sodium dithionite, described previously.
