反应详情

温度

90 °C

A 50-mL round bottomed flask fitted with a nitrogen inlet and magnetic stir bar was charged with (S)-isopropyl 7-bromo-4-(cyclopropanecarbonyl)-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate (0.801 g, 2.1 mmol), dioxane (11 mL), and water (4.6 mL). Cesium carbonate (2.053 g, 6.30 mmol) and tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-carboxylate (0.927 g, 3.15 mmol) were then added. The reaction was purged with nitrogen and bis(triphenylphosphine)palladium (II) dichloride (0.177 g, 0.252 mmol) was added. The mixture was heated at 90° C. with vigorous stirring for 5 h and then cooled to ambient temperature. Water (25 mL) was added, and the mixture was extracted with ethyl acetate (3×25 mL). The combined organic extracts were concentrated to afford a viscous oil and purified via column chromatography (gradient elution with 75-100% ethyl acetate-hexanes). The resulting material was triturated with diethyl ether (2×10 mL) to afford (S)-isopropyl 4-(cyclopropanecarbonyl)-3-methyl-7-(1H-pyrazol-4-yl)-3,4-dihydroquinoxaline-1(2H)-carboxylate (0.55 g, 71% yield) as a solid. MS (ESI, pos. ion) m/z 369 [M+1]+.

1. customA 50-mL round bottomed flask fitted with a nitrogen inlet and magnetic stir bar
2. additionwas added
3. temperaturecooled to ambient temperature
4. extractionthe mixture was extracted with ethyl acetate (3×25 mL)
5. concentrationThe combined organic extracts were concentrated
6. customto afford a viscous oil
7. custompurified via column chromatography (gradient elution with 75-100% ethyl acetate-hexanes)
8. customThe resulting material was triturated with diethyl ether (2×10 mL)