desired compound is prepared according to general procedure 2 starting from 3 2 bromomethyl 1 3 dioxolan 2 yl thiophene 2 sulphonamide of example 1 with a yield of 90 1 h nmr 300 mhz dmso d 6 8 69 t 1h 7 89 d 1h 7 18 d 1h 4 17 m 2h 4 06 m 2h 3 54 d 2h the desired compound is prepared according to general procedure 2 starting from 3 2 bromomethyl 1 3 dioxolan 2 yl 5 chlorothiophen 2 sulphonammide of example 2 with a yield of 97 1 h nmr 300 mhz dmso d 6 8 91 t 1h 7 34 s 1h 4 17 m 2h 4 04 m 2h 3 56 d 2h the compound of structure 3 is dissolved in dmso 5 10 volumes potassium carbonate is added 1 2 2 5 equivalents and the mixture is heated for one hour at 50 60 u00b0 c when the conversion is complete 1 chloro 3 methoxypropane 1 5 3 equivalents is added to the suspension and the mixture is heated again at 60 u00b0 c for 2 8 hours when the conversion is complete the mixture is recovered with water and toluene the phases are separated and the organic phase is washed with water the product 9 is isolated through distillation of the solvent under vacuum obtaining a solid with a hplc assay of 85 95 and a yield of 90 99 the desired compound is prepared according to the general procedure 3 starting from 3 2 bromomethyl 1 3 dioxolan 2 yl thiophene 2 sulphonamide of example 1 with a yield of 90 1 h nmr 300 mhz dmso d 6 7 94 d 1h 7.