the treatment of various cardiac arrythmias said sulfonamide base compounds are of the formula str1 wherein r and r 1 are each c 1 c 4 alkyl x is ch 2 co or co n is two three or four and 34 het 34 is a nitrogen containing heterocyclic group wherein said heterocyclic group is phenyl or benzyl substituted 2h pyridazin 3 on 2 yl or it is 2h phthalazin 1 on 2 yl 4 halo 2h phthalizin 1 on 2 yl or 4 2h phthalazin 1 on 2 yl 2h isoindolin 1 on 2 yl 3h quinazolin 4 on 3 yl 2h 3 4 dihydroisoquinol 1 on 2 yl 2h isoquinol on 2 yl 1h 3 4 dihydroquinol 2 on 1 yl benzoxazol 2 on 3 yl quinol 2 on 1 yl quinol 2 yl or indol 2 yl each optionally mono substituted with halogen or c 1 c 4 alkyl on the benzene portion of the respective fused ring moieties application_number US 36051789 A description the compounds of the formula i can be prepared by the following general routes 1 the first route to compounds in which x is ch 2 or co can be illustrated as follows str6 q is a suitable leaving group e g cl br i methanesulphonyloxy phenylsulphonyloxy or p toluenesulphonyloxy preferably br r r 1 het and n are as defined for formula i and x is ch 2 or co the reaction is preferably carried out in the presence of a base 34 acid acceptor 34 such as triethylamine or sodium bicarbonate typically the reaction is carried out in a suitable solvent e g ethanol.