反应详情

To a mixture of (4-{[2-(2-furyl)-5-methyl-1,3-oxazol-4-yl]methoxy}-3-(methoxymethoxy)phenyl)methanol (8.50 g), tributylphosphine (9.95 g), ethyl 1-benzyl-3-hydroxy-1H-pyrazole-4-carboxylate (6.06 g) and tetrahydrofuran (300 mL) was added 1,1′-(azodicarbonyl)dipiperidine (12.41 g) at room temperature, and the mixture was stirred for 2 hrs. The precipitated crystals were removed by filtration and the filtrate was concentrated. The residue was subjected to silica gel column chromatography to give ethyl 1-benzyl-3-[(4-{[2-(2-furyl)-5-methyl-1,3-oxazol-4-yl]methoxy}-3-(methoxymethoxy)benzyl)oxy]-1H-pyrazole-4-carboxylate as colorless crystals (12.42 g, yield 88%) from a fraction eluted with ethyl acetate-hexane (1:2, v/v). Recrystallization from ethyl acetate-hexane gave colorless needle crystals. melting point: 120-121° C.

1. customThe precipitated crystals were removed by filtration
2. concentrationthe filtrate was concentrated