DIPEA (180 μL, 1.05 mmol), HOBT (68 mg, 0.5 mmol), (2S)-5-oxotetrahydrofuran-2-carboxylic acid (CAS Reg. No: [21461–84–7], 0.5 mmol, 65 mg) and EDAC (120 mg, 0.63 mmol) were added to a suspension of N-[(1R,2R)-1-amino-2,3-dihydro-1H-inden-2-yl]-2-chloro-6H-thieno[2,3-b]pyrrole-5-carboxamide (Method 21, 223 mg, 0.5 mmol) in anhydrous DCM (7 mL). The reaction was stirred at ambient temperature for approximately 16 h. The volatiles were removed by evaporation under reduced pressure, the residue dissolved in EtOAc (5 mL), washed with water (2×5 mL), brine (10 mL) and dried (MgSO4). The volatiles were removed by evaporation under reduced pressure and the residue triturated (EtOAc:hexane, 1:10), collected by filtration, washed with hexane (2×5 mL) and dried to give the title compound (112 mg, 56%) as a brown solid.
