Tetrahydro-4H-pyran-4-one → 5-chloro-6-methoxy-1-[1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one

Participants

Reaction Steps

6-Methoxy-5-chloro-1-(4-piperidinyl)-1,3-dihydro-2H-benzimidazol-2-one hydrochloride (D50) (30 mg, 0.1 mmol), Ti(iPrO)4 (0.15 ml, 0.5 mmol), and tetrahydro-4H-pyran-4-one (50 mg, 0.5 mmol) were stirred together at room temperature for 1 h; dry methanol (1 ml) followed by NaBH3CN (30 mg, 0.5 mmol) were added and the mixture was stirred at room temperature for 2 h. The crude mixture was then quenched with methanol and it was purified first by SCX column chromatography followed by silica gel chromatography (10% methanol-NH3-dichloromethane) to afford 5-chloro-6-methoxy-1-[1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one. Conversion to the hydrochloride gave the title compound, 10 mg, MH+=366 and 368.

Provenance & Evidence