申请人:JOHN WYETH & BROTHER LIMITED
公开号:EP0276133A2
公开(公告)日:1988-07-27
The invention concerns a process for preparing a thiazolo[3,2-a]benzimidazole of formula I
in which formula n is 1 or 2, and R₁ is hydrogen, lower alkyl, lower alkoxy, trifluoromethyl or halo, or a salt thereof which comprises dehydrating a compound of formula II,
or a salt thereof wherein n and R, are as defined above, and COOR is an acid or ester function in the presence of an acid selected from sulphuric, sulphonic and phosphoric acid or mixtures thereof and if desired or required an inert solvent provided that if water is present then the amount of water is less than about 15% by volume of the acid, the reaction being carried out with heating if necessary.
本发明涉及一种制备式 I 的噻唑并[3,2-a]苯并咪唑或其盐的工艺。
式中 n 为 1 或 2,R₁ 为氢、低级烷基、低级烷氧基、三氟甲基或卤素的噻唑或其盐的制备方法,该方法包括使式 II、
或其盐,其中 n 和 R 如上文所定义,COOR 是酸或酯官能团,存在的酸选自硫酸、磺酸和磷酸或它们的混合物,如果需要或需要惰性溶剂,条件是如果有水存在,则水的量小于酸体积的约 15%,必要时加热进行反应。