Acetanilide [103-84-4-A] C8H9NO
About the reaction: The primary amine aniline is acetylated by reaction with acetic anhydride.
Procedure: In a 250-ml round-bottom flask, 20.0 ml (0.22 mol) of freshly distilled aniline is placed and 20.0 ml of glacial acetic acid (0.35 mol) is added while stirring. To the mixture, 20.0 ml (0.21 mol) of freshly distilled acetic anhydride is added dropwise, followed by 0.3 g of zinc dust. Adding glacial acetic acid, but especially adding acetic anhydride, causes strong heating. Attach a reflux condenser to the round-bottom flask, heat the reaction mixture, and let it boil for 30 minutes. Pour the still hot solution cautiously with intensive stirring into 500 ml of ice water, rinsing the flask with 10 ml of glacial acetic acid. Excess zinc powder is left in the flask during rinsing. The product, which precipitates in colorless flakes, is filtered, washed with 200 ml of ice water, and dried in the air. This yields 25.5 g of acetanilide with a melting point of 113-114 °C, corresponding to 86% of the theoretical yield. The acetanilide can be recrystallized from ethanol/water (1:4) for purification, raising the melting point to 114-115 °C.
 |
 |
Note: The reaction progress can be monitored using thin-layer chromatography. SiO2-TLC plates and ethyl acetate as the solvent are used (Rf ≈ 65).
Source: Th. Eicher and H. J. Roth; Synthesis, Production and Characterization of Pharmaceuticals, Georg Thieme Verlag, Stuttgart 1986
Delivered by: Mephisto
Photos delivered by: Heuteufel
Created: 13/04/2006
Last updated: 31/12/2012
Other names: Acetylaminobenzene; Acetaniline; Antifebrin; Acetic acid anilide; N-Phenylacetamide