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

Participants

Reaction Conditions

Reaction Steps

To a solution of methanesulfonyl chloride (6.96 g, 61.06 mmol) in acetonitrile (150 mL) was added dropwise a mixture of 3-chloro-1-(3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxylic acid (i.e. the carboxylic acid product of Step D) (15.0 g, 58.16 mmol) and triethylamine (5.88 g, 58.16 mmol) in acetonitrile (150 mL) at −5° C. The reaction mixture was then stirred for 30 minutes at 0° C. Then, 2-amino-3-methyl-5-chlorobenzoic acid (i.e. the product from Example 1, Step A) (10.79 g, 58.16 mmol) was added, and stirring was continued for an additional 10 minutes. A solution of triethylamine (11.77 g, 116.5 mmol) in acetonitrile was then added dropwise while keeping the temperature below 10° C. The reaction mixture was stirred 60 minutes at 0° C., and then methanesulfonyl chloride (6.96 g, 61.06 mmol) was added. The reaction mixture was then warmed to room temperature and stirred for an additional 2 hours. The reaction mixture was then concentrated, and the crude product was chromatographed on silica gel using methylene chloride as eluent to afford the title product as a yellow solid (9.1 g).

Provenance & Evidence