反应详情

温度

0 °C

Tert-butyl {[5-(benzyloxy)pyridin-3-yl](phenylsulfonyl)methyl}carbamate (2.2 g, 4.84 mmol) was suspended in a toluene (16.5 mL) water (13 mL) mixture. At 0° C. tert-butyl methyl malonate (1.0 mL, 5.8 mmol), cesium carbonate (1.58 g, 4.84 mmol) and 1-[3,5-bis(trifluoromethy)phenyl]-3-[(1R,2R)-(−)-2-(dimethylamino)cyclohexyl]thiourea (200 mg, 0.48 mmol) was added and the mixture was stirred for 48 hours at 0° C. After storage at 5° C. for 72 hours the mixture was diluted with water and ethyl acetate, the phases were separated and the aqueous phase extracted with ethyl acetate. The combined extracts were dried over sodium sulfate and concentrated. The residue was purified by chromatography on silica gel (ethyl acetate in hexane 0% to 60%) to yield 1.54 g of enantiomerically enriched tert-butyl methyl 2-{(1S)-[5-(benzyloxy)pyridin-3-yl][(tert-butoxycarbonyl)amino]methyl}propanedioate.

1. customthe phases were separated
2. extractionthe aqueous phase extracted with ethyl acetate
3. dry with materialThe combined extracts were dried over sodium sulfate
4. concentrationconcentrated
5. customThe residue was purified by chromatography on silica gel (ethyl acetate in hexane 0% to 60%)