Acetic Anhydride → 4'-Bromo-2'-(trifluoromethyl)acetanilide

Temperature

0 °C

A solution of 2-(trifluoromethyl)-4-bromoaniline (4.8 g, 20 mmol) in dry tetrahydrofuran (20 mL) was cooled to 0° C. and then treated with acetic anhydride (8.2 g, 80 mmol). The reaction mixture was stirred at 0° C. for 10 min and then allowed to warm to 25° C. The reaction mixture was stirred at 25° C. for 2 h, at which time, thin layer chromatography analysis of the reaction mixture indicated the absence of starting material. The reaction mixture was then concentrated in vacuo. The crude residue precipitated from diethyl ether (50 mL) and hexanes (50 mL). The solid was collected by filtration and washed with hexanes to afford N-(4-bromo-2-trifluoromethyl-phenyl)-acetamide (5.07 g, 90%) as an amorphous white solid: EI-HRMS m/e calcd for C9H7BrF3NO (M+) 281.8352, found 281.8348.

1. temperatureto warm to 25° C
2. stirringThe reaction mixture was stirred at 25° C. for 2 h, at which time, thin layer chromatography analysis of the reaction mixture
3. concentrationThe reaction mixture was then concentrated in vacuo
4. customThe crude residue precipitated from diethyl ether (50 mL) and hexanes (50 mL)
5. filtrationThe solid was collected by filtration
6. washwashed with hexanes

ORD record

ord-00ce45a0cdd14c449d764631030531e4

Source dataset

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06369232B1