Hydrogen Peroxide → 6-Amino-5-chloro-2-(4-chloro-2-fluoro-3-methanesulfinylphenyl)pyrimidine-4-carboxylic acid methyl ester

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Reaction Steps

6-Amino-5-chloro-2-(4-chloro-2-fluoro-3-methylthio-phenyl)pyrimidine-4-carboxylic acid methyl ester (2.4 g, 6.63 mmol) was dissolved with heating in a minimum amount of trifluoroethanol (50 mL). After allowing the reaction mixture to cool to room temperature, 30% hydrogen peroxide (3.0 mL, 26.5 mmol) was added and the reaction mixture was stirred for 2 days. An aqueous solution of sodium sulfite (10% solution) was added to quench excess oxidant (exotherm noted) and the reaction mixture was stirred for 1 hour. Additional water was then added and the reaction mixture was filtered. The precipitate was found to be pure 6-amino-5-chloro-2-(4-chloro-2-fluoro-3-methanesulfinylphenyl)pyrimidine-4-carboxylic acid methyl ester (2.13 g, 85% yield): mp 256-258° C.: 1H NMR (CDCl3): δ 8.03 (dd, 1H), 7.54 (dd, 1H), 3.92 (s, 3H), 3.13 (s, 3H).

Provenance & Evidence