Cesium carbonate → 6-Chloro-2-methyl-4-(5-(oxetan-3-yl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-yl amino)pyridazin-3(2H)-one

Participants

Reaction Conditions

Reaction Steps

In a 250 mL round-bottomed flask, 5-(oxetan-3-yl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-amine (555 mg, 2.86 mmol, Eq: 1.00), 4-bromo-6-chloro-2-methylpyridazin-3(2H)-one (638 mg, 2.86 mmol, Eq: 1.00) cesium carbonate (3.26 g, 10.0 mmol, Eq: 3.50) and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (248 mg, 429 μmol, Eq: 0.15) were combined with dioxane (40 ml) and the reaction mixture was vacuum flushed 3× with argon. Bis(dibenzylideneacetone)palladium (123 mg, 214 μmol, Eq: 0.075) was added and the reaction was heated at 90° C. for 18 hr. After cooling to room temperature it was diluted with 50 mL dichloromethane and water. The aqueous layer was back-extracted with DCM (2×25 mL).The combined organic layers were dried over MgSO4 and concentrated in vacuo to near dryness. The resulting solid was collected by filtration and washed with ethyl ether. A second crop of solid that formed in the filtrate and washes was collected by filtration and washed with ethyl ether. The combined solids were dried under vacuum to afford the desired product (669 mg) as a solid. (M+H)+=337 m/e. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 3.01 (t, J=5.18 Hz, 2 H) 3.73 (s, 2 H) 3.81 (s, 3 H) 3.92 (t, J=6.44 Hz, 1 H) 4.26 (t, J=5.43 Hz, 2 H) 4.79 (d, J=6.57 Hz, 4 H) 5.77 (s, 1 H) 7.60 (s, 1 H) 7.88 (s, 1 H).

Provenance & Evidence