To a stirred solution of 4-(6-chloro-4-(ethoxycarbonyl)chroman-7-yloxy)benzoic acid (Preparation 1; 0.75 g; 2.0 mmol), 1-hydroxybenzotriazole hydrate, and 2-(2,4-dichloro-6-methoxyphenyl)ethanamine (Preparation 7; 0.48 g, 2.19 mmol) in 6 mL DMF at ambient temperature was added solid 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.46 g; 2.4 mmol). The resulting solution was stirred at ambient temperature overnight for convenience. The solution was diluted with 60 mL water and after stirring for 10 minutes, the mixture was transferred to a separatory funnel and extracted with 30 mL EtOAc. 1M HCl (30 mL) was added to enable layer separation. The organic layer was dried over sodium sulfate and evaporated. The residue was purified by silica gel chromatography on a Biotage 40M column, eluting with 70/30 hexane/EtOAc, to give 0.56 g of ethyl 6-chloro-7-(4-(2,4-dichloro-6-methoxyphenethylcarbamoyl)phenoxy)chroman-4-carboxylate as a white glass. MS (apci, pos) m/z=578.
