92.1% |
With tetrabutyl ammonium fluoride; acetic acid; In acetic acid butyl ester; N,N-dimethyl-formamide; at 30 - 35℃; for 15.0h; |
At room temperature, 70g of the starting compound I was added to 250mL of butyl acetate, stirred until nearly clear,Slowly add glacial acetic acid 48g, stir until the reaction solution is clear,Rinse the bottle wall with 10 mL of butyl acetate,Then add tetrabutylammonium fluoride,Rinse the bottle wall with 20 mL of butyl acetate,After stirring to clarify, add 140 mL of DMF, warmed to 30 ~ 35 C reaction 15h; TLC detection reaction was completed, add 420mL butyl acetate,The reaction solution was cooled to about 10 C,Temperature below 15 C dropping saturated sodium carbonate solution,Adjust the pH to 7 ~ 8, stirring 30min retest pH7 ~ 8,The layers were allowed to stand and extracted twice with 70 mL × 2 butyl acetate.The combined organic layers were added with saturated sodium bicarbonate 400mL × 2 extraction, standing stratification,The organic layer was washed with 400 mL × 2 saturated sodium chloride.The organic layer was added anhydrous magnesium sulfate, charcoal injection,Stirring decoloration drying 2 hours, filtered,The filtrate control the internal temperature below 50 C , concentrated to dryness under reduced pressure. The above method was prepared as a pale yellow solid Intermediate II 47.7g, molar yield of 92.1%, liquid chromatogram shown in Figure1 shown. |