反应详情

A solution of (±)-1-(2-chloro-3-(trifluoromethyl)benzyl)-6-cyclopropyl-3-methoxy-5,6-dihydropyrazin-2(1H)-one (216 mg, 0.58 mmol) and pyrazine-2-carbohydrazide (88 mg, 0.63 mmol) in 1-butanol (5.8 mL) was heated at 130° C. for 16 h. After cooling to rt, the solvent was removed in vacuo. Purification by chromatography (SiO2; hexanes—100% EtOAc) afforded the desired product as a white solid (116 mg, 45%). MS (ESI): mass calcd. for C20H16ClF3N6O, 448.1; m/z found, 449.1 [M+H]+. 1H NMR (400 MHz, CDCl3) δ 9.69-9.58 (m, 1H), 8.70 (d, J=2.6 Hz, 1H), 8.64 (dd, J=2.5, 1.5 Hz, 1H), 7.75-7.62 (m, 2H), 7.38 (t, J=7.8 Hz, 1H), 5.49 (d, J=15.9 Hz, 1H), 5.27-5.16 (m, 1H), 4.78 (dd, J=15.6, 1.7 Hz, 1H), 4.68 (ddd, J=13.9, 4.5, 2.4 Hz, 1H), 3.16 (ddd, J=9.9, 4.5, 3.3 Hz, 1H), 1.06-0.96 (m, 1H), 0.80-0.72 (m, 1H), 0.67-0.43 (m, 2H), 0.28-0.21 (m, 1H).

1. customthe solvent was removed in vacuo
2. customPurification by chromatography (SiO2; hexanes—100% EtOAc)