To a solution of (3-thienylsulphonyl)acetonitrile (59.4 mg, 0.318 mmol) in DMF (1 mL) was added NaH (95%, 8.08 mg, 0.344 mmol). After stirring 5 min at room temperature, 5-isothiocyanato-2-methylbenzofuran (50 mg, 0.265 mmol) was added in one portion. The reaction was heated at 50° C. for 30 min. To the mixture was added 1-[[(3S)-3-aminohexahydro-2-oxo-1H-azepin-1-yl]acetyl]pyrrolidine (76.0 mg, 0.318 =mol), WSC (101.7 mg, 0.53 mmol) and N,N-dimethyl 4-pyridinamine (cat.) in that order. The reaction mixture was stirred at room temperature overnight. Water was added to the reaction and the mixture was extracted with ethyl acetate three times. The combined organic fractions were washed once with brine, dried over magnesium sulfate and evaporated. The residue was chromatographed (silica, 5% methanol/ethyl acetate) to provide 1-[[(3S)-3-[[2-[(3-thienyl)sulfonyl]-2-cyano-1-[(2-methyl-5-benzofuranyl)amino]-1-ethenyl]amino]hexahydro-2-oxo-1H-azepin-1-yl]acetyl]pyrrolidine (63.0 mg, 41%): HPLC (method A) tR 3.65 min; LRMS (ESI, pos. ion spectrum) m/z 582 (M+H).
