Reaktion #61410

Reaktionsgleichung

citric acid monohydrate

water

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

ethyl chloroformate

→

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

Ausbeute 72.7%

Lösungsmittel

2,4,6-trimethylpyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISTILLATIONthe resulting mixture was purified by ODS solid phase extraction (washing solvent: distilled water, eluent: methanol)
2. 2
   SonstigeFurther purification by column chromatography
3. 3
   Sonstigeon silica gel (eluent: dichloromethane/methanol=10/1) and recrystallization (recrystallization solvent: ethyl acetate/hexane=1/3)

Vorschrift

To a solution of 3-(β-D-glucopyranosyloxy)-4-[(4-iso-propoxyphenyl)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=10/1) and recrystallization (recrystallization solvent: ethyl acetate/hexane=1/3) afforded 3-(6-O-ethoxy-carbonyl-β-D-glucopyranosyloxy)-4-[(4-isopropoxyphenyl)methyl]-1-isopropyl-5-methylpyrazole (0.084 g).

Quelle