2,2-Difluoro-2-(fluorosulfonyl)acetic acid → 4-Difluoromethoxy-pyrrolidine-1,2-dicarboxylic acid 2-[2-(4-bromo-phenyl)-2-oxo-ethyl]ester 1-tert-butyl ester

温度

45 °C

To 4-Hydroxy-pyrrolidine-1,2-dicarboxylic acid 2-[2-(4-bromo-phenyl)-2-oxo-ethyl]ester 1-tert-butyl ester (500 mg) and Cu(I)I (45 mg) in MeCN (8 mL) at 45° C. was added 242 μl of difluoro-fluorosulfonyl-acetic acid in 2 mL of MeCN dropwise for 60 min. The reaction mixture was stirred at 45° C. for 60 min. and evaporated under reduced pressure, and resulting residue was taken up in ethyl acetate (100 mL). The organic phase was washed with brine (1×100 mL) and dried over sodium sulfate. After the solvent was removed, the resulting oil was subjected to silica gel chromatography using effluent of 10-50% ethyl acetate and hexanes. The fractions containing product were combined and the solvent was removed under reduced pressure to provide 4-Difluoromethoxy-pyrrolidine-1,2-dicarboxylic acid 2-[2-(4-bromo-phenyl)-2-oxo-ethyl]ester 1-tert-butyl ester (339 mg, 61%) as a clear oil.

1. customevaporated under reduced pressure
2. customresulting residue
3. washThe organic phase was washed with brine (1×100 mL)
4. dry with materialdried over sodium sulfate
5. customAfter the solvent was removed
6. additionThe fractions containing product
7. customthe solvent was removed under reduced pressure

ORDレコード

ord-bc5a242d17964534b78def3f8b7912f9

出典データセット

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08822430B2