| 摘要 |
<p>This invention concerns a process for removing a sulfonyl group from the l-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 l-position of a benzimidazole to allow conversion of 2-amino-1,6-substituted-benz-imidazole compounds into 2-amino-1,5-substituted-benzimidazole compounds.</p> |
