2,6-Dimethoxypyridine-3-carboxylic acid → acetic acid (1RS,3RS,4RS)-4-{[1-(2,6-dimethoxy-pyridin-3-yl)methanoyl]amino}-3-(3-ethoxy-4-methoxyphenyl)cyclohexyl ester

Participants

Reaction Conditions

Reaction Steps

555 mg of 2,6-dimethoxynicotinic acid and 581 mg of N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide hydrochloride are placed in a flask under nitrogen. 778 mg of acetic acid (1RS,3RS,4RS)-4-amino-3-(3-ethoxy-4-methoxyphenyl)cyclohexyl ester (compound B1) and 2 mg of 4-dimethylaminopyridine both as solution in dichloromethane are added and the solution stirred for 1 h at 40° C., than 42 h at room temperature. The reaction is quenched with 5 ml of water. After phase separation the organic layer is washed with 2.5 ml of saturated potassium hydrogencarbonate solution. After drying the organic layer with magnesium sulfate the solvent is removed to give 1.227 g of the crude title compound which are used for the following step without further purification.

Provenance & Evidence