Triethylamine → 2-[1-(3-chloro-2-pyridinyl)-3-(trifluoromethyl)-1H-pyrazol-5-yl]-6-iodo-8-methyl-4H-3,1-benzoxazin-4-one

Participants

Reaction Conditions

Reaction Steps

To a solution of methanesulfonyl chloride (2.91 mL, 37.74 mmol) in acetonitrile (50 mL) was added dropwise a mixture of 1-(3-chloro-2-pyridinyl)-3-(trifluoromethyl)-1H-pyrazole-5-carboxylic acid (i.e. the carboxylic acid product of Step C) (10.0 g, 34.31 mmol) and triethylamine (4.78 mL, 34.31 mmol) in acetonitrile (50 mL) at −5° C. The reaction temperature was then maintained at 0° C. throughout successive addition of reagents. After stirring for 20 minutes, 2-amino-3-methyl-5-iodobenzoic acid (i.e. the product from Step A) (9.51 g, 34.31 mmol) was added and stirring was continued for an additional 10 minutes. A solution of triethylamine (9.56 mL, 68.62 mmol) in acetonitrile (15 mL) was then added dropwise, and the reaction mixture was stirred 30 minutes, followed by the addition of methanesulfonyl chloride (2.91 mL, 37.74 mmol). The reaction mixture was then warmed to room temperature and stirred 2 hours. The solvent was evaporated under reduced pressure, and the residual solid was purified by chromatography on silica gel to afford 8.53 g of the title compound as a yellow solid.

Provenance & Evidence