A solution of 100 mg (4.18 mmol) LiOH in 6 mL water was added to a solution of 980 mg (1.83 mmol) (R)-1-methoxycarbonyl-2-(2-methoxy-7-methyl-1H-benzimidazol-5-yl)-ethyl 4-(2-oxo-1,2,4,5-tetrahydro-1,3-benzodiazepin-3-yl)-piperidine-1-carboxylate in 18 mL THF and the reaction mixture was stirred overnight at RT. 1.05 mL of 4 M HCl was added, the THF was evaporated down i.vac., whereby the crude product was produced in the form of an oil. The water was decanted off, the residue was dissolved in DCM/MeOH and dried over Na2SO4. After the desiccant and solvent had been eliminated the residue was further reacted without purification.
