Hydrogen Peroxide → 3-(Methanesulfonyl)-5-[(pyridin-4-yl)amino]-1,2-thiazole-4-carboxamide

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Reaction Steps

Compound 8 (500 mg, 1.88 mmol) is slurried in acetic anhydride (1.25 mL) and acetic acid (1.25 mL). Hydrogen peroxide (30%, 0.532 mL, 4.7 mmol) is added and stirred for 1 hour. Additional hydrogen peroxide (30%, 0.532 mL, 4.7 mmol) is then added and the reaction is stirred for 1 hour. Water (about 15 mL) is added and the solids were filtered and further dried in vacuo. These solids were determined to be mainly 3-Methanesulfinyl-5-(pyridin-4-ylamino)-isothiazole-4-carboxylic acid amide. The solids are thus re-combined with the mother liquor and acetic anhydride (2.0 mL), acetic acid (2.0 mL) and hydrogen peroxide (30%, 2 mL) are added and stirred for 18 hours at room temperature. The reaction was then extracted with ethyl acetate (15 mL×3) and the combined organics were dried over sodium sulfate, then filtered and concentrated in vacuo obtain crude 3-Methanesulfonyl-5-(pyridin-4-ylamino)-isothiazole-4-carboxylic acid amide (9) (170 mg).

Provenance & Evidence