white to almost white fine crystalline powder
Acetylsalicylic Acid Impurity C
Antiinflammatory;Cyclooxygenase inhibitor
ChEBI: 2-[(2-acetyloxyphenyl)-oxomethoxy]benzoic acid is a carbonyl compound.
To a solution of 2-((2-hydroxybenzoyl)oxy)benzoic acid (5.0 g, 19.37 mmol) in ethanoic anhydride (15.0 mL, 147.0 mmol) was added 3 drops of concentrated hydrochloric acid. The reaction mixture was stirred at room temperature for 16-20 hours. After completion of the reaction, the mixture was diluted with ice-cold water (50 mL) and the precipitated solid was collected by filtration. The solid was washed sequentially with water (2 x 10 mL) and hexane (20 mL) and dried to give 2-((2-acetoxybenzoyl)oxy)benzoic acid (5.5 g) as a white solid. Thin layer chromatography (TLC) Rf value was 0.3 (unfolding agent: 50% ethyl acetate/hexane).
Crystallise the analgesic from dilute AcOH or EtOH (m 161-162o), MeOH (m 165-168o), and *C6H6/EtOH (m 163-165o). Its solubilities in boiling Et2O, *C6H6 and EtOH are 1.4%, 2.2% and 33%, respectively. [Baker et al. J Chem Soc 201 1951, Garrett et al. J Am Pharm Soc 48 684 1959, Beilstein 10 I 41, 10 II 54, 10 IV 165.]
[1] Chemical and Pharmaceutical Bulletin, 1985, vol. 33, # 5, p. 2158 - 2161
[2] Patent: US2014/357680, 2014, A1. Location in patent: Paragraph 0135-0136
[3] Patent: WO2014/195961, 2014, A1. Location in patent: Paragraph 00125; 00126
