Water → HCID 14510255, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of 80% sodium hydride (1.22 g, 41 mmol) in anhydrous dimethylformamide (90 mL), was added dropwise a solution of N-(3,5-difluorophenyl)-2-pyridinecarboxamide, prepared by the process of Example 1, Step 1 (8.71 g, 37 mmol) in dimethylformamide (30 mL). The reaction mixture was warmed to 65° C. for 1 hour and then treated with iodomethane (2.60 mL, 42 mmol) at room temperature. After 2.5 hours the reaction mixture was poured into water (500 mL) and extracted with ethyl acetate (2×300 mL). The combined organic layers were washed with 75% brine, dried, preabsorbed onto silica gel, and flash chromatographed (300 g, elution with 40% ethyl acetate in petroleum ether) to yield pure N-(3,5-difluorophenyl)-N-methyl-2-pyridinecarboxamide (5.16 g, 21 mmol, 56%, m.p. 102°-104° C.), which was reacted with Lawesson's reagent (4.36 g, 11 mmol) in anhydrous toluene (65 mL) at reflux temperature for 1.5 hours. The toluene was evaporated and the residue was dissolved in dichloromethane, preadsorbed onto silica gel, flash chromatographed (300 g, elution with 10% ethyl acetate in petroleum ether), and recrystallized from ethyl acetate in petroleum ether to afford a yellow solid (2.36 g, 24%), m.p. 131°-134° C.

Provenance & Evidence