Dichloromethane → 1,6-Dihydro-1-[2-(6-chloro-3-pyridinylcarbonylamino)ethyl]-6-oxo-3-pyridinecarboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a 1 00 ml round bottomed flask fitted with a magnetic stirrer bar and nitrogen inlet was added the above amine (0.300 g, 1.53 mmol), 6-chloro-3-pyridinecarboxylic acid (0.241 g, 1.53 mmol), and dry dichloromethane 125.5 mmol). Upon cooling in a -8° C. ice bath with stirring, triethyl amine (1.07 ml, 7.65 mmol) and propylphosphonic acid anhydride (0.50 ml, added as a 0.50 ml ethyl acetate solution, Angew. Chemie 1980, 92(2), 129) were added. The flask was allowed to warm slowly to room temperature over 1.25 hours. Stirring was continued 30 minutes at which time the reaction mixture solution was washed with aqueous sodium bicarbonate (2X), brine, and dried (Na2SO4). Filtration, concentration and purification via medium pressure liquid chromotography (silica gel, 4% methanol/dichloromethane) have the desired product, MP: 188°-190° C.

Provenance & Evidence