The condensation of 3-cyanophenyl isocyanate (I) with N-Boc-4-aminopiperidine (II) produced the corresponding urea (III). The diazepinone system (V) was then obtained by dialkylation of the urea (III) functionality with 1,4-dibromobutane (IV) in the presence of NaH. After acid cleavage of the Boc protecting group of (V), the resulting piperidine (VI) was acylated with 2-thiophenesulfonyl chloride (VII) to give sulfonamide (VIII). Addition of methanol to the cyano group of (VIII) in the presence of anhydrous HCl in MeOAc furnished imidate (IX). This was then converted to the corresponding amidine by treatment with either methanolic ammonia or (NH4)2CO3, followed by conversion to the title hydrochloride salt.

The condensation of 3-cyanophenyl isocyanate (I) with N-Boc-4-aminopiperidine (II) produced the corresponding urea (III). The diazepinone system (V) was then obtained by dialkylation of the urea (III) functionality with 1,4-dibromobutane (IV) in the presence of NaH. After acid cleavage of the Boc protecting group of (V), the resulting piperidine (VI) was acylated with 2-thiophenesulfonyl chloride (VII) to give sulfonamide (VIII). Addition of methanol to the cyano group of (VIII) in the presence of anhydrous HCl in MeOAc furnished imidate (IX). This was then converted to the corresponding amidine by treatment with either methanolic ammonia or (NH4)2CO3, followed by conversion to the title hydrochloride salt.