This invention concerns a process for removing a sulfonyl group from the 1-position of a benzimidazole to allow conversion of 2-amino-1,5-substituted-benzimidazole compounds into 2-amino-1.6-substituted-benzimidazole compounds. The 5-isomer is reacted with an alkali metal hydroxide or carbonate in an inert aqueous organic solvent system. The reaction mixture is acidified to precipitate the base and form the intermediate benzimidazole tautomer. The intermediate is then reacted with a sulfonyl acylating agent or a haloalkyl isothiocyanate to form a mixture of 2-amino-1,5(6)-substituted-benzimidazole compounds. This invention also concerns the process for removing a sulfonyl group from the 1-position of a benzimidazole to allow conversion of 2-amino-1,6-substituted-benzimidazole compounds into 2-amino-1,5-substituted-benzimidazole compounds.
本发明涉及一种从
苯并咪唑的 1 位去除磺酰基,从而将 2-
氨基-1,5-取代
苯并咪唑化合物转化为 2-
氨基-1.6-取代
苯并咪唑化合物的工艺。在惰性含
水有机溶剂体系中,5-异构体与碱
金属氢氧化物或
碳酸盐发生反应。将反应混合物酸化,使碱沉淀,形成中间体
苯并咪唑同系物。然后将中间体与磺酰基酰化剂或卤代烷基异
硫氰酸酯反应,形成 2-
氨基-1,5(6)-取代的
苯并咪唑化合物混合物。本发明还涉及从
苯并咪唑的 1 位上去除磺酰基,使 2-
氨基-1,6-取代的
苯并咪唑化合物转化为 2-
氨基-1,5-取代的
苯并咪唑化合物的工艺。