To a suspension of 3-(6-(methoxycarbonyl)-3,3-dimethyl-1,2,3,4-tetrahydroquinolin-2-yl)benzoic acid (150 mg, 0.44 mmol, 1.0 eq.) in dichloromethane (10.0 ml) was added N-hydroxy benzotriazole (89.2 mg, 0.66 mmol, 1.5 eq.) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide.hydrochloric acid (253.0 mg, 1.32 mmol, 3.0 eq.), followed by 4-methylmorpholine (133.5 mg, 1.32 mmol) and the resultant mixture was stirred at room temperature for 40 min. Then N1, N1-dimethylethane-1,2-diamine (42.7 mg, 0.48 mmol, 1.1 eq.) was added to the flask and the reaction mixture was stirred for an additional 40 min, LC-MS showed the reaction was complete. The reaction was quenched with water, separated, and the aqueous layer was extracted with dichloromethane (twice). The combined organic layers were washed with 2% sodium hydroxide aqueous solution (twice) and brine (3 times), dried over anhydrous magnesium sulfate. Removal of the solvent in vacuo gave 191 mg of methyl 2-(3-(2-(dimethylamino)ethylcarbamoyl)phenyl)-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-6-carboxylate as a off-white solid, which was washed with hexane and collected by filtration to afford 162 mg product as a white solid. Yield: 89.5%.
