Isopropylamine → N-[2-Methyl-6-[[(1-methylethyl)amino]carbonyl]phenyl]-1-phenyl-3-(trifluoromethyl)-1H-pyrazole-5-carboxamide

Participants

Reaction Conditions

Reaction Steps

A sample of 3-methylisatoic anhydride (0.30 g, 1.7 mmol) partially dissolved in pyridine (4.0 mL) was treated with 1-phenyl-3-(trifluoromethylpyrazole)-5-carboxyl chloride (i.e. the product of Step C) (0.55 g, 1.9 mmol). The mixture was heated to ˜95° C. for a period of 2 hours. The resulting orange solution was cooled to 29° C., then was treated with isopropylamine (1.00 g, 16.9 mmol). The reaction mass exothermically warmed to 39° C. It was further heated to 55° C. for a period of 30 minutes, whereupon much precipitate formed. The reaction mass was dissolved in dichloromethane (150 mL). The solution was washed with aqueous acid (5 mL of conc. HCl in 45 mL of water), then with aqueous base (2 g sodium carbonate in 50 mL of water). The organic layer was dried over MgSO4, filtered, then concentrated on a rotary evaporator. Upon reduction to ˜4 mL, product crystals had formed. The slurry was diluted with ˜10 mL of ether, whereupon more product precipitated. The product was isolated by filtration, washed with ether (2×10 mL), then washed with water (2×50 mL). The wet cake was dried for 30 minutes at 70° C. in vacuo. The product, a compound of the present invention, consisted of 0.52 g of an off-white powder melting at 260-262° C.

Provenance & Evidence