Dimethyl Sulfoxide → Tert-butyl 4-[4-(5-chloro-2-{2-cyano-4-[(1,2,4-thiadiazol-5-ylamino)sulfonyl]phenoxy}phenyl)pyrimidin-2-yl]piperazine-1-carboxylate

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Reaction Steps

3-Cyano-4-fluoro-N-(1,2,4-thiadiazol-5-yl)benzenesulfonamide (Preparation 65, 43.6 mg, 0.154 mmol), tert-butyl 4-[4-(5-chloro-2-hydroxyphenyl)pyrimidin-2-yl]piperazine-1-carboxylate (Preparation 873, 50.0 mg, 0.128 mmol) and potassium carbonate (53 mg, 0.38 mmol) in dimethyl sulfoxide (1 mL, 10 mmol) was stirred at 100° C. for 16 hours. The reaction mixture was cooled to ambient temperature and poured into saturated aqueous ammonium chloride. The aqueous layer was extracted with ethyl acetate (3×). The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to afford the crude intermediate, tert-butyl 4-[4-(5-chloro-2-{2-cyano-4-[(1,2,4-thiadiazol-5-ylamino)sulfonyl]phenoxy}phenyl)pyrimidin-2-yl]piperazine-1-carboxylate, as a yellow solid. Trifluoroacetic acid (300 uL, 4 mmol) was added to a solution of tert-butyl 4-[4-(5-chloro-2-{2-cyano-4-[(1,2,4-thiadiazol-5-ylamino)sulfonyl]phenoxy}phenyl)pyrimidin-2-yl]piperazine-1-carboxylate (83 mg, 0.154 mmol) in methylene chloride (2.9 mL, 46 mmol). After 1 hour, the reaction mixture was concentrated in vacuo. The residue was purified by reverse-phase HPLC to afford the product as a white solid (trifluoroacetic acid salt, 36 mg, 51%).

Provenance & Evidence