1-Hydroxybenzotriazole → 2-[3-chloro-4-(methylsulfonyl)phenyl]-3-[(2R,3R,7R)-2,3-diphenyl-1,4-dioxaspiro[4.4]non-7-yl]-N-methoxy-N-methylpropaneamide

Participants

Reaction Steps

A solution of N-methoxymethanamine hydrochloride (936 mg) in acetonitrile (40 mL) was neutralized with triethylamine (3.35 mL), and 2-[3-chloro-4-(methylsulfonyl)phenyl]-3-[(2R,3R,7R)-2,3-diphenyl-1,4-dioxaspiro[4.4]non-7-yl]propanoic acid (4.33 g), N-[3-(dimethylamino)propyl]-N′-ethylcarbodiimide hydrochloride (2.30 g) and 1-hydroxybenzotriazole (612 mg) were added under ice-cooling. The reaction mixture was stirred overnight at room temperature, diluted with ethyl acetate, and washed with water and saturated aqueous sodium hydrogen carbonate. The ethyl acetate layer was dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and the title compound (3.05 g, yield 69%) was obtained as a colorless amorphous solid from a fraction eluted with ethyl acetate-hexane (3:1, volume ratio).

Provenance & Evidence