The invention provides a method for catalytically synthesizing a 3, 4-dihydrobenzothiadiazine
medicine by using
rare earth. According to the method, trifluoromethanesulfonic acid
rare earth salt is taken as a catalyst, 4-amino-6-
chlorobenzene-1, 3-disulfonamide, 4-amino-6-trifluoromethylbenzene-1, 3-disulfonamide and corresponding
aldehyde are taken as raw materials, and seven 3, 4-difluorobenzene-1, 3-disulfonamide compounds are simply and conveniently prepared through one-step reaction. The compound is prepared from 2, 4-dihydrobenzothiadiazine medicines: cyclothiazide, buthiazide, cyclopenthiazide,
hydrochlorothiazide, bendrofluthiazide, penfluthiazide and ethyl thiazide. The
medicine has the effects of inducing
diuresis, reducing
blood pressure, resisting
anxiety, resisting depression, treating
edema and the like clinically. The synthesis method provided by the invention has the advantages of mild
reaction conditions, simple operation, simple steps and high synthesis efficiency, has industrial application prospects, and plays a positive role in the fields of medicines,
fine chemical engineering and the like.