4-Piperidinecarboxamide → 1-[4'-(Trifluoromethyl)-[1,1'-biphenyl]-2-carbonyl]piperidine-4-carboxamide

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Reaction Steps

4′-(Trifluoromethyl)-2-biphenylcarboxylic acid (20.5 g; 77 mmol) is dissolved in 340 ml of dimethylformamide and 200 ml of dichloromethane. The reaction medium is placed at 0° C. and oxalyl chloride (1.8 eq.; 138.6 mmol; 12 ml) is added. The reaction medium is stirred at room temperature for 3 hours and then evaporated to dryness. The crude product is taken up in 270 ml of dichloromethane, followed by addition of a solution of isonipecotamide (0.97 eq.; 74.7 mmol; 9.57 g) and triethylamine (2.7 eq.; 207.9 mmol; 29 ml) in 270 ml of dichloromethane, placed at 0° C. The mixture is allowed to warm to room temperature over 12 hours, saturated aqueous sodium hydrogen carbonate solution is then added (in a 1/1 proportion) and the resulting mixture is stirred for 30 minutes. The organic phase is washed with 1M sodium hydroxide solution and then with water, dried over sodium sulfate and evaporated to dryness. The crude product is dispersed in diisopropyl ether and then filtered off and dried to give 23.09 g of coupling product.

Provenance & Evidence