Lithium Hydroxide → 2,6-Difluoro-4-(5-methyl-3-phenyl-isoxazol-4-yl)benzenesulfonamide

Participants

Reaction Steps

To a mixture of {[2,6-difluoro-4-(5-methyl-3-phenylisoxazol-4-yl)phenyl]sulfonyl}methyl acetate (1.5 g, 3.9 mmol) in THF (25 mL) and methanol (25 mL) was added a solution of lithium hydroxide (0.50 g, 12 mmol) in water (4 mL). The resulting solution was stirred at room temperature for 1 hour. Additional solution of lithium hydroxide (0.60 g, 14 mmol) in water (8 mL) was added, followed by solid hydroxylamine sulfonic acid (1.6 g, 14.1 mmol) and methanol (5 mL). The reaction mixture was stirred overnight and poured into water (250 mL). The 2,6-difluoro-4-(5-methyl-3-phenyl-isoxazol-4-yl)benzenesulfonamide was isolated as a white solid (1.08 g, 85%). MP 226.1-226.2° C. 1H NMR (CD3OD/400 MHz) 7.36-7.46 (m, 5H), 6.95 (d, 2H, J=9.4), 2.51 (s, 3H). ESHRMS m/z 351.0621 (M+H+, Calcd 351.0615). Anal. Calcd for C,16H12F2N2O3S: C, 54.85; H, 3.45; N, 8.00; Found: C, 54.95; H, 3.51, N 7.81.

Provenance & Evidence