N-[(1R,2R)-1-Amino-2,3-dihydro-1H-inden-2-yl]-2,3-dichloro-4H-thieno[3,2-b]pyrrole-5-carboxamide trifluoroacetate salt (Method 8, 223 mg, 0.5 mmol) was dissolved in THF (4 mL) and the solution cooled to 0° C. Et3N (223 μL, 1.6 mmol) then methanesulfonyl chloride (43 μL, 0.55 mmol) were added and the reaction was stirred 0° C. for 5 mins. Saturated aqueous NaHCO3 (5 mL) was added, the phases separated and the aqueous phase extracted with EtOAc (3×10 mL). The combined organic fractions were washed with H2O (20 mL), dried (MgSO4) and the solvent removed under reduced pressure. The residue was subjected to purification by reverse phase preparative HPLC to afford the title compound (30 mg, 15%) as a white solid.
