Lithium Hexamethyldisilazide → (R)-2-(2-ethoxy-5-oxo-2,5-dihydrofuran-3-ylcarbamoyl)-pyrrolidine-1-carboxylic acid tert-butyl ester

温度

0 °C

To a solution of 4-amino-5-ethoxy-5H-furan-2-one (0.08 g, 0.58 mmol) in tetrahydrofuran (10 mL) at −78° C. under nitrogen was dropwise added a solution of 1M lithium bis(trimethylsilyl)amide in tetrahydrofuran (0.64 mL, 0.64 mmol). The reaction was stirred 3 h at 0° C. A solution of 2-fluorocarbonyl-pyrrolidine-1-carboxylic acid tert-butyl ester (0.20 g, 0.77 mmol) in tetrahydrofuran (3 mL) was added dropwise. The reaction was stirred for 16 h at room temperature. The mixture was diluted with ethyl acetate, was washed with 10% sodium bisulfate, saturated sodium bicarbonate, and brine, was dried over sodium sulfate, and was evaporated. Purification by flash chromatography (SiO2) eluted with 35:65 ethyl acetate:hexanes afforded (R )-2-(2-ethoxy-5-oxo-2,5-dihydrofuran-3-ylcarbamoyl)-pyrrolidine-1-carboxylic acid tert-butyl ester (0.05 g, 26% yield). Also isolated was starting 4-amino-5-ethoxy-5H-furan-2-one (0.03 g, 36% yield).

1. stirringThe reaction was stirred for 16 h at room temperature
2. washwas washed with 10% sodium bisulfate, saturated sodium bicarbonate, and brine
3. dry with materialwas dried over sodium sulfate
4. customwas evaporated
5. customPurification by flash chromatography (SiO2)
6. washeluted with 35:65 ethyl acetate

ORDレコード

ord-54320d7519264a06bfd58d15a624883f

出典データセット

uspto-grants-2006_09

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07109357B2