Chloroacetyl chloride → (2S,4S)-1-(2-Chloroacetyl)-4-fluoropyrrolidine-2-carbonitrile

A solution of step 3 intermediate (10 g, 32.89 mmol) and triethylamine (4.32 g, 42.77 mmol) in dichloromethane (200 ml) was added drop wise to a stirred and cooled (0° C.) solution of chloroacetyl chloride (4.81 g, 32.95 mmol) in dichloromethane (50 ml) over a period of 10 min. The mixture was stirred at the same temperature for 2 h and diluted with dichloromethane (100 ml) and water (100 ml) under stirring. The layers were separated. The organic layer was washed with water (2×50 ml), brine (50 ml) and dried (Na2SO4). The residue obtained after evaporation of the solvent was triturated with diethyl ether to give 5.89 g (94%) of the product as an off-white solid, IR (KBr) 2924, 2241, 1678, 1407, 1281, 1225, 1076, 1051, 958 cm−1; 1H NMR (CDCl3, 300 MHz) δ 2.26-2.48 (m, 1H), 2.66-2.80 (m, 1H), 4.06 (s, 2H), 3.81-4.29 (m, 2H), 4.95 (d, J=9.6 Hz, 0.8H, rotomer), 5.38 (brd, J=51.3 Hz, 0.2H, rotomer) 5.46 (d, J=9.0 Hz, 0.2H, rotomer), 5.46 (dt, J=44.4, 3.3 Hz, 0.8H, rotomer).

1. stirringThe mixture was stirred at the same temperature for 2 h
2. stirringunder stirring
3. customThe layers were separated
4. washThe organic layer was washed with water (2×50 ml), brine (50 ml)
5. dry with materialdried (Na2SO4)
6. customThe residue obtained
7. customafter evaporation of the solvent
8. customwas triturated with diethyl ether

ORD record

ord-00052bd3b0394c4da7bae736019fb9ce

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07538128B2