Acetic Anhydride → 2-(Acetylamino)-3-(3-bromo-4-fluorophenyl)-2-propenoic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-bromo-4-fluorobenzaldehyde (50.0 g, 0.25 mol), N-acetylglycine (26.2 g, 0.22 mol), NaOAc (13.8 g, 0.56 mol), and Ac2O (52 mL) was heated at 130° C. for 10 h in a flask fitted with a reflux condenser. The resulting precipitate was collected by filtration, washed with water, and suspended in AcOH (250 mL). This mixture was heated at 100° C. for 1 h in a flask fitted with a reflux condenser, and then was cooled to 0° C. The solids were collected by filtration, washing with water, to give the product as a yellow solid (53.5 g, 76%). MS (ESI−): mass calcd. for C11H9BrFNO3, 301.0; m/z found, 299.9 [M−H]−. 1H NMR (400 MHz, DMSO-d6): 12.80 (br s, 1H), 9.52 (br s, 1H), 7.93 (dd, J=6.9, 1.9, 1H), 7.66 (ddd, J=8.4, 4.8, 1.9, 1H), 7.42 (t, J=8.7, 1H), 7.19 (s, 1H), 1.98 (s, 3H).

Provenance & Evidence