Phosgene → HCID 10596787, compound

Participants

Reaction Steps

To 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-6-fluoro-4,5-dihydroimidazo[1,5-a]quinoxaline (XXXIII, EXAMPLE 103, 0.418 g) in THF (15 ml) is added diisopropylethylamine (0.245 ml) followed by phosgene (1.2M in toluene, 1.76 ml). The reaction is stirred for 3 hr, after which pyrrolidine (0.23 ml) and diisopropylethylamine (0.25 ml) are added. The reaction is stirred for 1 hr, then treated with several ml of water and concentrated. The residue is partitioned between dichloromethane, aqueous sodium bicarbonate, and saline. The phases are separated, the organic phase is dried over sodium sulfate and concentrated. The crude product is chromatographed on silica gel (150 ml) eluting with methanol/dichloromethane (2/98). The appropriate fractions are pooled and concentrated to give the product which is recrystallized from dichloromethane and hexane to give the title compound, mp 220.5°-221.5°; MS m/z at 394; IR (mineral oil) 1500, 1392, 1662, 1221, 793 and 1613 cm-1 ; NMR (CDCl3), 1.35, 1.86, 2.26, 3.33, 5.10, 7.08, 7.21, 7.37 and 8.11 δ.

Provenance & Evidence