Butanoic acid, 4-chloro-4-oxo-, ethyl ester → HCID 11569937, Verbindung

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a nitrogen purged flask was added 4-[5-amino-1-(2,6-difluorobenzoyl)-1H-[1,2,4]triazol-3-ylamino]-benzenesulfonamide Compound 1a (1.0 g, 2.5 mmol) and THF (100 mL). The mixture was cooled to 0° C. and potassium tert-butoxide (2.8 mL, 1.0 M solu in THF) was added dropwise. After addition the mixture was stirred at 0° C. for 1 hr, then ethyl 4-chloro-4-oxobutyrate (0.46 g in 10 mL THF, 2.8 mmol) was added dropwise. The stirring was continued for 30 min, then the mixture was warmed to rt and stirred overnight. After being concentrated, the residue was purified by flash chromatography (silica gel, CH2Cl2:MeOH/9:1) to afford the desired product (200 mg, 15%) as a white solid. 1H NMR (300 MHz, CD3OD) δ 7.72 (d, 2H), 7.70 (m, 1H), 7.50 (d, 2H), 7.15 (t, 2H), 4.20 (q, 2H), 3.32 (s, 2H), 2.71 (s, 2H), 1.25 (t, 2H); MS (ESI) m/z: 523 (M+H)+.

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