4-Methylmorpholine → 5-((E)-2-{3-[(4-{[2-(2-furyl)-5-methyl-1,3-oxazol-4-yl]methoxy}-3-methoxybenzyl)oxy]-1-phenyl-1H-pyrazol-4-yl}ethenyl)-3-propyl-1,2,4-oxadiazole

Participants

Reaction Steps

A mixture of (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 (0.60 g), 4-methylmorpholine (0.28 g), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.21 g), 1-hydroxybenzotriazole monohydrate (0.17 g) and N,N-dimethylformamide (30 mL) was stirred at room temperature for 30 min, N′-hydroxybutanimidamide (0.14 g) was added, and the mixture was further stirred at room temperature for 15 hrs. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated. Xylene (50 mL) was added to the residue, and the mixture was heated under reflux for 24 hrs. The reaction mixture was concentrated, and the obtained residue was subjected to silica gel column chromatography to give 5-((E)-2-{3-[(4-{[2-(2-furyl)-5-methyl-1,3-oxazol-4-yl]methoxy}-3-methoxybenzyl)oxy]-1-phenyl-1H-pyrazol-4-yl}ethenyl)-3-propyl-1,2,4-oxadiazole as colorless crystals (0.12 g, yield 18%) from a fraction eluted with ethyl acetate-hexane (1:2, v/v). Recrystallization from ethyl acetate-hexane gave colorless prism crystals. melting point: 192-193° C.

Provenance & Evidence