Synthesis of 2, 3-Dihydro-1, 4-benzodioxin Derivatives. I. : 2-Substituted-5(and 6)-sulfamoyl-2, 3-dihydro-1, 4-benzodioxins

In order to study new sulfonamide diuretics, two series of 6- and 5-sulfamoyl-2, 3-dihydro-1, 4-benzodioxins were synthesized and tested for diuretic and antihypertensive activities in rats. Starting from 4-chloro(or 3, 4-dichloro)-1, 2-dihydroxybenzene, these sulfamoyl compounds were prepared by two different routes. In method A, 6-sulfamoyl compounds (8 or 11) were obtained by conversion of the nitro function into sulfonamide via the Sandmeyer reaction. In method B, 5-sulfamoyl compounds (16) were synthesized by direct introduction of sulfonyl chloride into the dihydrobenzodioxin, followed by amination. The sulfamoyl dihydrobenzodioxins showed lower diuretic and antihypertensive activities than trichloromethiazide.