反应详情

To a mixture of N,O-dimethylhydroxylamine hydrochloride (0.56 g) and N,N-dimethylformamide (30 mL) was added triethylamine (0.69 g) at room temperature, and the mixture was stirred for 15 min. To the reaction mixture were added (2E)-3-{3-[(4-{[2-(2-furyl)-5-methyl-1,3-oxazol-4-yl]methoxy}-3-methoxybenzyl)oxy]-1-phenyl-1H-pyrazol-4-yl}-2-propenoic acid (2.0 g), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (1.09 g) and 1-hydroxybenzotriazole monohydrate (0.87 g), and the mixture was further stirred at room temperature for 20 hr. Water was added to the reaction mixture and the precipitated crystals were collected by filtration to give (2E)-3-{3-[(4-{[2-(2-furyl)-5-methyl-1,3-oxazol-4-yl]methoxy}-3-methoxybenzyl)oxy]-1-phenyl-1H-pyrazol-4-yl}-N-methoxy-N-methyl-2-propenamide as colorless crystals (1.92 g, yield 88%). Recrystallization from ethyl acetate-hexane gave colorless prism crystals. melting point: 173-174° C.

1. stirringthe mixture was further stirred at room temperature for 20 hr
2. filtrationthe precipitated crystals were collected by filtration