Dichloromethane → 6-[(1-Methylethyl)oxy]-1-[1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one hydrochloride

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Reaction Steps

A solution of 6-[(1-methylethyl)oxy]-1-(4-piperidinyl)-1,3-dihydro-2H-benzimidazol-2-one (D50, 229 mg, 0.89 mmol) in dichloromethane (10 ml) was treated with tetrahydro-4H-pyran-4-one (623 mg, 6.23 mmol), sodium triacetoxyborohydride (1.3 g, 6.23 mmol) and triethylamine (270 mg, 3.67 mmol) and stirred at room temperature for 2 hrs. The mixture was diluted with dichloromethane, then aqueous NaOH solution (pH12) was added and the organic layer separated. The NaOH solution was extracted with dichloromethane (×2) and the combined dichloromethane extracts was washed with aqu, NaOH solution, dried (MgSO4) and concentrated under vacuum to leave a pale orange oil, which was purified by chromatography on silica gel eluting with 0-50% of 10% methanol/dichloromethane: dichloromethane to afford the title compound as a pale orange solid (101 mg, 33%). M++H=360.2 which was converted to its HCl salt.

Provenance & Evidence