Synthesis
Step 1: Synthesis of ethyl 2-(4-chlorophenyl)-2-oxoacetate
Aluminum trichloride (25.5 g, 192.0 mmol) was slowly added to a stirred solution of chlorobenzene (10 mL, 100.0 mmol) and ethyl 2-chloro-2-oxoacetate (17 mL, 146.0 mmol) in dichloromethane (250 mL) at 0 °C. After addition, the reaction mixture was gradually warmed to room temperature and stirring was continued for 12 hours. After completion of the reaction, the reaction mixture was diluted with ethyl acetate (500 mL) and washed sequentially with water (300 mL) and saturated saline (300 mL). The organic layer was separated, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 10:1 to 5:1) to afford ethyl 4-chlorobenzoylformate (14 g, 67% yield) as a light-colored oil. Mass spectra (electrospray positive ion mode) C10H9ClO3 theoretical values: 212, 214; measured values: 213, 215 [M + H]+.
References
[1] Journal of Organic Chemistry, 1996, vol. 61, # 18, p. 6407 - 6415
[2] Patent: US2017/22206, 2017, A1. Location in patent: Paragraph 0174; 0175; 0176
[3] Journal of Organic Chemistry, 2008, vol. 73, # 10, p. 3842 - 3847
[4] Organic Letters, 2011, vol. 13, # 24, p. 6520 - 6523
[5] Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2013, vol. 52, # 6, p. 818 - 823
