Trifluoroacetic acid → 5-[4-[5-(2,6-Difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]hexahydropyrrolo[3,4-c]pyrrole

To a stirred solution of 1,1-dimethylethyl 5-[4-[5-(2,6-difluorophenyl)-4,5-dihydro-3-isoxazolyl]-2-thiazolyl]hexahydropyrrolo[3,4-c]pyrrol-2(1H)-carboxylate (i.e. the product of Step C) (0.6 g, 1.26 mmol) in dichloromethane (15 mL) cooled to 0° C. was added trifluoroacetic acid (2 mL, 26.93 mmol). The reaction mixture was allowed to warm to room temperature, stirred for 3 h, and then concentrated under reduced pressure. The resulting material was dissolved in water (50 ml) and basified by the addition of sodium hydroxide (10%) to pH 12, and then extracted with chloroform (3×50 mL). The combined organic extracts were concentrated under reduced pressure to provide the title product as a white-gummy solid (0.42 g).