Dicyclohexylcarbodiimide → 4-Hydroxy-benzoic acid [2-(4-hydroxy-phenyl)-1-methoxycarbonyl-ethyl carbamoyl]-methoxycarbonylmethyl ester

Participants

Reaction Steps

A solution of 4-hydroxy-benzoic acid carboxymethyl ester 16 (11.8 grams, 60.20 mmol) and 2-(2-hydroxy-acetylamino)-3-(4-hydroxy-phenyl)-propionic acid methyl ester 3 (15.23 grams, 60.19 mmol) in anhydrous dichloro methane (100 mL) under a nitrogen atmosphere at 0° C. is added to a solution of 1,3-dicyclohexyl carbodiimide (31 grams, 150.24 mmol) in dichloro methane (75 mL) drop wise. The mixture is stirred at room temperature for 6 hours. The resulting solids are filtered off. The organic phase is washed with 5% sodium bicarbonate (2×25 mL) and water (2×25 mL), dried over sodium sulphate, and distilled to give crude 17 which can be purified in an appropriate solvent.

Provenance & Evidence