Synthesis
Under argon protection, 820 mg of 3-bromobenzoic acid (4.0 mmol) was suspended in 14 mL of a 6:1 dichloromethane (DCM)/acetonitrile (MeCN) solvent mixture, to which 800 mg of HOBt (4.44 mmol) and 861 mg of EDOHCl (4.4 mmol) were added. After stirring for 10 min, the mixture changed to a clarified solution, which was subsequently cooled to 0 °C in an ice bath. In another round-bottomed flask, 1.64 g NaOH (40 mmol) was added to 2.8 mL of 28% NH4OH solution (20 mmol), and the resulting gaseous NH3 was passed through a NaOH trap and then drummed into the reaction vessel. After stopping the NH3 drumming, the reaction mixture was concentrated under reduced pressure and the residue was dissolved in ethyl acetate (AcOEt, 60 mL) and washed sequentially with 5% KHSO4 (2 × 30 mL), water (20 mL), 5% NaHCO3 (3 × 20 mL) and brine (20 mL). The organic phase was dried with Na2SO4, filtered and evaporated to dryness under reduced pressure to give 700 mg of 3-bromobenzamide in 87% yield.
References
[1] Patent: WO2017/12890, 2017, A1. Location in patent: Page/Page column 28
[2] Phosphorus, Sulfur and Silicon and the Related Elements, 2007, vol. 182, # 3, p. 657 - 666
[3] Tetrahedron Letters, 2005, vol. 46, # 40, p. 6879 - 6882
[4] Journal of Organic Chemistry, 2003, vol. 68, # 16, p. 6431 - 6434
[5] Chemische Berichte, 1871, vol. 4, p. 707
