反应详情

温度

23 °C

tert-Butyldimethylsilyltrifluoromethanesulfonate (9.99 ml, 11.49 g, 43.5 mmol, 3.0 equiv) was added to a stirring solution of 3-methyl-5-oxo-2,5-dihydro-pyrrole-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (3.7 g, 14.5 mmol, 1.0 equiv) and 2,6-lutidine (5.07 ml, 4.66 g, 43.5 mmol, 3.0 equiv) in dichloromethane (100 ml) at 23° C. The mixture was stirred at 23° C. for 15 h, then washed with pH=7 buffer solution (30 ml). The aqueous layer was extracted with two 40 ml portions of dichloromethane. The combined organic layers were dried over sodium sulfate. The solids were filtered and the filtrate was concentrated. The residue was purified by flash column chromatography (3% ethyl acetate-hexanes initially, grading to 6% ethyl acetate-hexanes) to afford 5-(tert-Butyl-dimethyl-silanyloxy)-3-methyl-1H-pyrrole-2-carboxylic acid methyl ester (3.46 g, 89%) as a yellow oil.

1. washwashed with pH=7 buffer solution (30 ml)
2. extractionThe aqueous layer was extracted with two 40 ml portions of dichloromethane
3. dry with materialThe combined organic layers were dried over sodium sulfate
4. filtrationThe solids were filtered
5. concentrationthe filtrate was concentrated
6. customThe residue was purified by flash column chromatography (3% ethyl acetate-hexanes initially