Triethylamine → 3-Amino-5-methoxy-1-quinolin-8-ylpyridazin-4(1H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-methoxy-4-oxo-1-quinolin-8-yl-1,4-dihydropyridazine-3-carboxylic acid (2.59 g, 8.71 mmol), DPPA (2.81 mL, 13.1 mmol) and Et3N (1.82 mL, 13.1 mmol) in toluene (26 mL) was heated to reflux for 1 h. To the suspension were added DMF (52 mL), DPPA (2.81 mL, 13.1 mmol) and Et3N (1.82 mL, 13.1 mmol) at room temperature. The mixture was heated to 100° C. for 1.5 h. To the mixture was added 8 M NaOH aqueous solution (10.9 mL) at 0° C. The mixture was stirred at room temperature for 1.5 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 EtOAc/MeOH=100/0 to 80/20) and on silica gel (EtOAc/MeOH=100/0 to 50/50) and triturated with EtOAc/hexane to yield the title compound (479 mg, 20% yield) as a pale yellow solid: 1H NMR (DMSO-d6, 300 MHz): δ ppm 3.75 (3H, s), 6.11 (2H, s), 7.67 (1H, dd, J=8.5, 4.4 Hz), 7.72-7.80 (1H, m), 7.99 (1H, dd, J=7.6, 1.5 Hz), 8.12 (1H, dd, J=8.3, 1.1 Hz), 8.48-8.61 (2H, m), 8.99 (1H, dd, J=4.4, 1.7 Hz).

Provenance & Evidence