5-Isoquinolinesulfonic acid (I) is heated at 85 C with SOCl2 and DMF yielding 5-isoquinolinesulfonyl chloride hydrochloride (II). The reaction of (II) with hexahydro-1H-1,4-diazepine affords hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine (III) in CH2Cl2. Finally, the reaction of (III) with HCl gives hexahydro-1-(5-isoquinolinesulfonyl)-1H-1,4-diazepine hydrochloride (IV). (scheme 10964901a)