反应详情

To a stirred solution of 5-benzyloxy-6-hydroxy-2-(8-phenyl-1,4-dioxa-spiro[4.5]dec-8-ylmethyl)-pyrimidine-4-carboxylic acid (270) (600 mg, 1.26 mmol) in dimethylformamide (12 mL) were added [2-(tert-butyl-dimethylsilanyloxy)-ethyl]-isopropyl-amine (8b) (411 mg, 1.89 mmol), N,N-diisopropylethylamine (0.63 mL, 3.78 mmol) and HATU (1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate) (574 mg, 1.51 mmol) and stirred at room temperature for 17 h (TLC, ethyl acetate:hexane=1:1/UV/SiO2, Rf=0.6). The reaction mixture was diluted with ethyl acetate (100 mL), washed with brine (3×50 mL), dried and concentrated in vacuum to get a crude mass which was purified by normal silica gel (100-200 mesh) column chromatography using gradient polarity eluent (1-2% methanol in dichloromethane) to get pure 5-benzyloxy-6-hydroxy-2-(8-phenyl-1,4-dioxa-spiro[4.5]dec-8-ylmethyl)-pyrimidine-4-carboxylic acid [2-(tert-butyl-dimethylsilanyloxy)-ethyl]-isopropylamide (271) (620 mg, 72.85%) as a brown sticky solid.

1. washwashed with brine (3×50 mL)
2. customdried
3. concentrationconcentrated in vacuum
4. customto get a crude mass which
5. customwas purified by normal silica gel (100-200 mesh) column chromatography