Diethyl Ether → N-[4-chloro-2-methyl-6-[(methylamino)carbonyl]phenyl]-1(3-chloro-2-pyridinyl)-3-(2,2,2-trifluoroethoxy)-1H-pyrazole-5-carboxamide

Participants

Reaction Steps

To a suspension of the 6-chloro-2-[1-(3-chloro-2-pyridinyl)-3-(2,2,2-trifluoroethoxy)-1H-pyrazol-5-yl]-8-methyl-4H-3,1-benzoxazin-4-one (i.e. precipitate product of Step E) (3.53 g, 7.5 mmol) in tetrahydrofuran (15 mL), methylamine (2.0 M solution in THF, 11 mL, 22 mmol) was added dropwise, and the resulting solution was stirred at room temperature for 45 minutes. Thin layer chromatography then showed the reaction to be complete. Ethyl ether (100 mL) was added, and the reaction mixture was stirred for 2 hours while a precipitate formed. The precipitate was collected by filtration and then recrystallized from acetonitrile to yield a white solid (0.82 g). A second crop of white solid (0.35 g) precipitated from the acetonitrile mother liquor and was collected by filtration. The initial ether/tetrahydrofuran mother liquor was concentrated to dryness, and the residual solid was recrystallized from acetonitrile to yield a third crop of white solid (0.95 g). The three crops were combined, totaling 2.12 g (after drying) of the title compound, isolated as a white solid, melting at 207-208° C.

Provenance & Evidence