2,2-Difluoro-2-(fluorosulfonyl)acetic acid → 4-Difluoromethoxymethyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

Temperature

45 °C

4-Hydroxymethyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (584 mg, 2.25 mmol) and CuI (86 mg, 0.45 mmol) were suspended in MeCN (10 mL). The reaction mixture was heated to 45° C. and difluoro-fluorosulfonyl-acetic acid (0.465 mL, 4.5 mmol) was added dropwise over the course of 30 min. Stirring was continued for another 3 h, after which the reaction mixture was cooled to RT and concentrated. The residue was taken up in EtOAc and washed with saturated aqueous NaHCO3 and brine then dried over MgSO4, filtered and concentrated. The crude residue was purified by silica column chromatography (19% to 40% EtOAc/Hex) to afford the title compound (394 mg, 57%).

1. temperatureafter which the reaction mixture was cooled to RT
2. concentrationconcentrated
3. washwashed with saturated aqueous NaHCO3 and brine
4. dry with materialthen dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe crude residue was purified by silica column chromatography (19% to 40% EtOAc/Hex)

ORD record

ord-8d28caebf29e4c9685d9e9ad2985445a

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08841278B2