Triethylamine → 1-(3-chloro-phenyl)-6-(4-nitro-phenyl)-7-oxo-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine-3-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

Part A: A 500 mL flask was charged with N-(3-chlorophenyl)-1-(ethoxycarbonyl)-methanehydrazonoyl chloride (3.67 g, 14.1 mmol), 3-morpholin-4-yl-1-(4-nitro-phenyl)-5,6-dihydro-1H-pyridin-2-one (2.14 g, 7.05 mmol), 50 mL of toluene, and triethylamine (3.57 g, 35.3 mmol). The mixture was heated at 80° C. overnight. After cooling to room temperature, the reaction mixture was treated with trifuloroacetic acid (10.1 g) at rt for 5 h. The mixture was concentrated to dryness under reduced pressure. The residue was dissolved in methylene chloride, washed water and brine, and dried with sodium sulfate. The crude product, after evaporation of the solvent, was purified by silica gel chromatography, eluting with 1:2 ethyl acetate/hexane to yield 1-(3-chloro-phenyl)-6-(4-nitro-phenyl)-7-oxo-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine-3-carboxylic acid ethyl ester (1.48 g). 1H NMR (300 MHz, CDCl3) δ 8.24 (2H, d, J=9.1 Hz), 7.60 (1H, t, J=1.8 Hz), 7.52 (2H, d, J=9.1 Hz), 7.47˜7.36(2H, m), 4.48 (2H, q, J=7.0 Hz), 4.22 (2H, t, J=6.6 Hz), 3.39 (2H, t, J=6.6 Hz), 1.45 (3H, t, J=7.0 Hz) ppm.

Provenance & Evidence