Trichloroacetonitrile → Trichloroacetimidic acid (S)-1-[3,5-bis(trifluoromethyl)phenyl]ethyl ester

Temperature

0 °C

A solution of 25.82 g (100 mmol) of (1S)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol in 200 mL dry diethyl ether under nitrogen atmosphere was cooled in an ice/water bath. Neat 3 mL (20 mmol, 0.2 equiv) DBU was added to the reaction flask then the mixture was stirred at 0° C. for ten min. Slowly 15 mL (150 mmol, 1.5 equiv.) trichloroacetonitrile was added dropwise over 15 min. The reaction was stirred at 0° C. for 2 hr. during which time it became deep yellow in color. The volatiles were removed under vacuum using a cool bath (<35° C.) to give a pale brown mobile liquid which was purified by column chromatography on silica gel (3″×10″ pad) in two batches eluting with hexanes/EtOAc (9/1) then hexanes/EtOAc (4/1). The product fractions were combined and the solvent removed under vacuum to give 37.5 g of the title compound as a pale yellow oil. 1H-NMR (CDCl3): δ: 1.74 (3H, d, J=6.5 Hz), 6.07 (1H, q, J=6.5 Hz), 7.82 (1H, s), 7.86 (2H, s), 8.40 (1H, br. s) ppm.

1. stirringThe reaction was stirred at 0° C. for 2 hr
2. customThe volatiles were removed under vacuum
3. custom(<35° C.)
4. customto give a pale brown mobile liquid which
5. customwas purified by column chromatography on silica gel (3″×10″ pad) in two batches
6. washeluting with hexanes/EtOAc (9/1)
7. customthe solvent removed under vacuum

ORD record

ord-d9692d2b70684ce7a47d9e4a86a75bd6

Source dataset

uspto-grants-2007_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07217731B2