Et3N (0.5 mL) was added into a solution of tert-butyl hexahydropyrrolo[3,4-c]pyrrole-2(1H)-carboxylate (0.2 g) and benzoyl chloride (0.11 mL) in THF (10 mL). The mixture was heated to 115° C. for 24 hours. The reaction was quenched with water (10 mL). The aqueous layer was extracted with EtOAc (3×10 mL). The combined organic phase was dried over MgSO4 and concentrated to give a residue which was purified by silica gel chromatography to give tert-butyl 5-benzoylhexahydropyrrolo[3,4-c]pyrrole-2(1H)-carboxylate.
