Triethylamine → 3-Amino-5-methoxy-1-(2,2,3,3,7-pentafluoro-2,3-dihydro-1,4-benzodioxin-6-yl)pyridazin-4(1H)-one

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Reaction Conditions

Reaction Steps

A mixture of 5-methoxy-4-oxo-1-(2,2,3,3,7-pentafluoro-2,3-dihydro-1,4-benzodioxin-6-yl)-1,4-dihydropyridazine-3-carboxylic acid (2.33 g, 5.91 mmol), DPPA (1.90 mL, 8.86 mmol) and Et3N (1.23 mL, 8.86 mmol) in toluene (23 mL) was heated to 100° C. for 90 min. To the mixture was added 8 M NaOH aqueous solution (7.4 mL) at 0° C. The mixture was stirred at room temperature for 2 h, extracted with EtOAc, dried over Na2SO4, filtered, concentrated in vacuo, purified by column chromatography on basic silica gel (hexane/EtOAc=50/50 to 0/100) and on silica gel (hexane/EtOAc=80/20 to 0/100) and triturated with EtOAc/hexane to yield the title compound (1.12 g, 53% yield) as a white solid: 1H NMR (DMSO-d6, 300 MHz): δ ppm 3.73 (3H, s), 6.24 (2H, s), 7.92 (1H, d, J=10.5 Hz), 7.99 (1H, d, J=6.8 Hz), 8.37 (1H, d, J=1.5 Hz).

Provenance & Evidence