反应详情

To a slurry consisting of 3-(5-cyclopropyl-1,2,4-oxadizol-3-yl)-4,5-dihydroimidazo[1,5-a]quinoxaline (XXXIII, EXAMPLE 88, 0.499 g), diisopropylethylamine (0.81 ml) and THF (15 ml) is added phosgene (1.93 M in toluene, 1.20 ml). A slight exotherm ensues and the slurry becomes homogeneous. After 10 min, morpholine (0.20 ml) is added. The mixture is stirred for 2 hr and then partitioned between ethyl acetate, water, and saline. The phases are separated and the organic phase is dried over magnesium sulfate and concentrated. The crude product is chromatographod on silica gel (150 ml) eluting with methanol/dichloromethane (2/98). The appropriate fractions are pooled and concentrated to give the product. Recrystallization from dichloromethane and hexane gives the title compound, mp 198.0°-198.5°; MS (m/z) at 392; IR 1662, 1506, 1409, 1277, and 1.579 cm-1 ; NMR (CDCl3) 1.24, 1.36, 2.27, 3.33, 3.64, 5.02, 7.21, 7.27, 7.55 and 8.11 δ.

1. custompartitioned between ethyl acetate, water, and saline
2. customThe phases are separated
3. dry with materialthe organic phase is dried over magnesium sulfate
4. concentrationconcentrated
5. washeluting with methanol/dichloromethane (2/98)
6. concentrationconcentrated
7. customto give the product
8. customRecrystallization from dichloromethane and hexane