Dimethylformamide → 4-(4-bromo-2-methylphenyl)-1-ethyl-3-(pyridin-2-yl)-4,5-dihydro-1H-pyrazolo[3,4-b]pyridin-6(7H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-(4-bromobenzylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (1.1 g, 3.54 mmol, Preparation W.1) and 1-ethyl-3-(pyridin-2-yl)-1H-pyrazol-5-amine (0.67 g, 3.54 mmol, prepared using B from Example #2, step A with ethyl hydrazine oxalate) in DMF (5 mL) was heated under nitrogen at about 60° C. for about 30 min. The reaction was cooled to rt, diluted with water (20 mL) and then the product was filtered off and rinsed with water (˜20 mL). The product was dried under vacuum at about 50° C. for about 16 h to yield 4-(4-bromo-2-methylphenyl)-1-ethyl-3-(pyridin-2-yl)-4,5-dihydro-1H-pyrazolo[3,4-b]pyridin-6(7H)-one as a tan solid (1.41 g, 3.54 mmol, 80%). LC-MS (Table 1, Method g) Rt=2.11 min, m/z 397/399 (M+H)+; 1H NMR (400 MHz, DMSO-d6) δ 10.88 (s, 1H), 8.44-8.41 (m, 1H), 7.84 (dt, J=8.0, 1.1 Hz, 1H), 7.77-7.69 (m, 1H), 7.43-7.36 (m, 2H), 7.21-7.17 (m, 1H), 7.10-7.04 (m, 2H), 6.63 (d, J=6.6 Hz, 1H), 4.22-4.03 (m, 2H), 3.14 (dd, J=16.0, 7.8 Hz, 1H), 2.53 (d, J=26.1 Hz, 1H), 1.33 (t, J=7.2 Hz, 3H).

Provenance & Evidence