The cyclization reactions have been performed in several solvents, the rate of the reaction was found to decrease in the order dimethyl sulfoxide> hexamethylphosphoric triamide> dimethylformamide> acetonitrile> benzene or diethyl ether. The reaction is easier with dipolar aprotic solvents. The great stability of the 1-bromo-2-aminoethanesulfonam-ides 4b- d allows their utilization for the introduction of the sulfonamido group to small-ring ...