Oxalyl chloride → 3-({3-[2-(tert-Butoxycarbonyl-pyridin-4-yl-amino)-ethoxy]-5-chloro-benzoyl}-phenyl-amino)-propionic acid methyl ester

Participants

Reaction Steps

2M Oxalyl chloride solution in dichloromethane (1.8 ml), and DMF (0.05 ml) were added to a suspension of 3-[2-(tert-butoxycarbonyl-pyridin-4-yl-amino)-ethoxy]-5-chloro-benzoic acid (1.18 g) in anhydrous dichloromethane (30 ml). The reaction was stirred at room temperature for 1 h then 3-phenylamino-propionic acid methyl ester (0.644 g), DMAP (0.036 g) and DIPEA (1.04 ml) were added. The reaction mixture was stirred at room temperature for 20 h and partitioned between ethyl acetate and 1M aqueous hydrochloric acid. The aqueous layer was removed and the organic phase washed with saturated aqueous sodium bicarbonate, water and dried with brine and over sodium sulphate and concentrated under reduced pressure. The residue was purified by flash column chromatography, eluting with ethyl acetate:petroleum ether (4:1 v/v) and neat ethyl acetate, to give the title compound as a colourless gum (1.22 g).

Provenance & Evidence