Ethyl Acetate → Tert-butyl 3-{5-[5-chloro-2-(4-{[(2,4-dimethoxybenzyl)(1,2,4-thiadiazol-5-yl)amino]sulfonyl}-2,5-difluorophenoxy)phenyl]-1H-pyrazol-1-yl}azetidine-1-carboxylate

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Reaction Steps

Tert-butyl 3-[5-(5-chloro-2-hydroxyphenyl)-1H-pyrazol-1-yl]azetidine-1-carboxylate (Preparation 851, 80.0 g, 0.2287 mol) and potassium carbonate (94.82 g, 0.686 mol) were combined in dimethylsulphoxide (600 mL). To this slurry was added N-(2,4-dimethoxybenzyl)-2,4,5-trifluoro-N-1,2,4-thiadiazol-5-ylbenzenesulfonamide, (Preparation 647, 101.87 g, 0.2287 mol) and stirred at room temperature for 4.5 hours. Ethyl acetate (1600 mL) and water (1000 mL) were added and the layers separated. The ethyl acetate was washed with water (2×800 mL), then saturated aqueous sodium chloride solution (200 mL) and then dried over anhydrous magnesium sulphate. To this suspension, tert-butylmethyl ether (250 mL) was added and the mixture was washed with dilute aqueous sodium chloride solution (1000 mL), the organics were dried over magnesium sulphate, filtered and the solvents removed in-vacuo to give a pale yellow solid. This solid was dissolved in dichloromethane (500 mL) and tert-butylmethyl ether was added gradually whilst evaporating the dichloromethane in vacuo to give a white precipitate which was filtered off and washed with a little tert-butylmethyl ether to give the title compound as a white solid, (145.47 g).

Provenance & Evidence