反応 #6754

反応方程式

citric acid monohydrate

water

3-(β-D-glucopyranosyloxy)-4-[(4-isopropoxyphenyl)methyl]-1-isopropyl-5-methylpyrazole

ethyl chloroformate

→

3-(6-O-ethoxycarbonyl-β-D-glucopyranosyloxy)-4-[(4-isopropoxyphenyl)methyl]-1-isopropyl-5-methylpyrazole

収率 72.4%

溶媒

2,4,6-trimethylpyridine

反応条件

後処理

1. 1
   workup.DISTILLATIONthe resulting mixture was purified by ODS solid phase extraction (washing solvent: distilled water, eluent: methanol)
2. 2
   その他Further purification by column chromatography
3. 3
   その他on silica gel (eluent: dichloromethane/methanol=1011) and recrystalization (recrystalization solvent: ethyl acetate/hexane=1/3)

実験手順

To a solution of 3-(β-D-glucopyranosyloxy)-4-[(4-isopropoxyphenyl)methyl]-1-isopropyl-5-methylpyrazole (0.10 g) in 2,4,6-trimethylpyridine (1 mL) was added ethyl chloroformate (0.072 g), and the mixture was stirred at room temperature overnight. To the reaction mixture were added citric acid monohydrate (3.3 g) and water, and the resulting mixture was purified by ODS solid phase extraction (washing solvent: distilled water, eluent: methanol). Further purification by column chromatography on silica gel (eluent: dichloromethane/methanol=1011) and recrystalization (recrystalization solvent: ethyl acetate/hexane=1/3) afforded 3-(6-O-ethoxycarbonyl-β-D-glucopyranosyloxy)-4-[(4-isopropoxyphenyl)methyl]-1-isopropyl-5-methylpyrazole (0.084 g).

出典