Cesium carbonate → HCID 22220908, compound

Participants

Reaction Steps

A mixture of 8-(5,5-dimethyl-[1,3,2]dioxaborinan-2-yl)-3-(5-methyl-3-phenylisoxazol-4-yl)-5H-[1,2,4]triazolo[3,4-α]isoindole (248 mg, 0.58 mmol) (as prepared in Example 26 Step (a)), methyl 6-chloropyrazine-2-carboxylate (100 mg, 0.58 mmol), dioxane (4.8 ml) and 2M aqueous Cs2CO3 solution (0.58 ml) was degassed with a stream of N2 for 10 min. Bis(triphenylphosphine)palladium dichloride (12 mg, 0.22 μmol) was added and the stirred mixture was heated at reflux for 1.5 h. The reaction was then cooled, allowed to stand for 15 min and the supernatent decanted off. The remaining salts were washed with further dioxane (5 ml) and then partitioned between water (20 ml) and CH2Cl2 (20 ml). The pH was adjusted to 6 by dropwise addition of 2N aqueous HCl and the aqueous phase was extracted with further CH2Cl2 (2×20 ml). The combined organic extracts were dried over Na2SO4 and concentrated in vacuo to yield the title compound as a white amorphous solid (89.8 mg, 34%); 1H NMR (400 MHz, CDCl3) δ 9.63 (1H, s), 9.19 (1H, s), 8.81 (1H, s), 8.38 (1H, dd, J=8.2, 1.7 Hz), 7.75 (1H, d, J=8.2 Hz), 7.56–7.48 (5H, m), 4.67 (2H, s), 2.64 (3H, s); m/z (ES+) 437 (M+H)+.

Provenance & Evidence