A solution of tert-butyl 3-(4-chlorophenyl)-3-(1-((R)-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-4-carbonyl)pyrrolidine-1-carboxylate (25 mg, 0.048 mmol) in DCM (2.5 mL) was added to a 4.0M HCl solution in dioxane (0.8 mL). The mixture was stirred at room temperature overnight. The solvents were removed in vacuo to give (3-(4-chlorophenyl)pyrrolidin-3-yl)(4-((R)-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)methanone dihydrochloride (24 mg, 100%). LCMS (APCI+) [M+H]+ 426.2; Rt: 2.09.
