反应详情

A solution of ethyl 4-cyclopropyl-2,4-dioxobutanoate (700 mg, 3.76 mmol), 3-methyl-1-(1-methylethyl)-1H-pyrazol-5-amine (523 mg, 3.76 mmol) and benzene (20 mL) were heated at 65° C. for 6 hr, and then allowed to cool to room temperature for 2 d. The solvent was removed under reduced pressure and the residue purified via silica gel chromatography (eluent: 0 to 25% EtOAc:Hex). The final product was collected as 0.77 g (71%). LCMS E-S (M+H)=288.0. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.04-1.11 (m, 2H), 1.13-1.20 (m, 4H), 1.47 (t, J=7.20 Hz, 6H), 1.55 (d, J=6.82 Hz, 12H), 2.16-2.25 (m, 2H), 2.68 (s, 6H), 4.49 (q, J=7.07 Hz, 4H), 5.20 (spt, J=6.78 Hz, 2H), 7.41 (s, 1H).

1. customThe solvent was removed under reduced pressure
2. customthe residue purified via silica gel chromatography (eluent: 0 to 25% EtOAc:Hex)
3. customThe final product was collected as 0.77 g (71%)