Oxalyl chloride → Ethyl 6,8-dichloro-7-(4-(4-chlorophenethylcarbamoyl)phenoxy)chroman-4-carboxylate

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Reaction Steps

4-(6,8-Dichloro-4-(ethoxycarbonyl)chroman-7-yloxy)benzoic acid (22.96 g, 55.832 mmol) was dissolved in dichloromethane (200 ml) and DMF (0.2 ml). Oxalyl chloride (8.6 ml, 98.585 mmol) was added slowly over a period of 30 minutes at ambient temperature. The crude mixture was concentrated under reduced pressure. Dry dichloromethane (200 ml) was added and the mixture was cooled in an ice bath. 2-(4-Chlorophenyl)ethylamine (8.5413 ml, 61.415 mmol) and diisopropylethylamine (11.701 ml, 66.999 mmol) were added sequentially to the mixture. The mixture was stirred in an ice bath for 10 minutes and warmed to ambient temperature. The crude mixture was washed with 1N HCl (100 ml), water (2×50 ml), and brine (50 ml), dried over MgSO4, filtered through GF paper, and concentrated to provide 30.1 g of a light brown solid after drying under high vacuum for 2 hours. The crude solid was recrystallized from hot EtOAc-hexanes to provide 26.8 g of the title compound as a light brown solid (87%).

Provenance & Evidence