反应详情

To a solution of 4-methoxy-3-((7-methyl-1H-indazol-5-yl)methyl)-4-oxobutanoic acid (0.9764 g, 3.54 mmol) and t-butyl-2,2,2-trichloroacetoimidate (3.78 mL, 21.22 mmol) in tetrahydrofuran (25 mL) was added 1M boron trifluoride etherate (0.2 mL) at room temperature. Heat generation was observed and the reaction was stirred for 3.5 h before passing it through a pad of silica gel. Evaporation of the filtrate gave a white solid. Methylene chloride (20 mL) was added and the resulting white solid was removed by filtration. The filtrate was concentrated and the final product was obtained via silica gel chromatography eluting with 0% to 50% ethyl acetate/hexane. (0.605 g, 52%) HPLC tR=1.51 min, MS(ESI)[M+H]+=332.77.

1. temperatureHeat generation
2. customEvaporation of the filtrate
3. customgave a white solid
4. customthe resulting white solid was removed by filtration
5. concentrationThe filtrate was concentrated