反应详情

To a mixture of 4,5-dihydro-5-[(pyrrolidino)carbonyl]imidazo[1,5-a]quinoxaline-3-carboxylic acid (I, EXAMPLE 323, 0.203 g), 0.060 g of aminoacetonitrile hydrochloride, and 3 ml of dichloromethane are added 0.23 ml of triethylamine and 0.15 ml of ethyl cyanophosphonate. A slight exotherm ensued. After about 45 min a precipitate formed and an additional 5 ml of dichloromethane are added. When the reaction had stirred for a total of 70 min it is partitioned between dichloromethane and aqueous sodium bicarbonate. The organic layers are dried over sodium sulfate and concentrated. The crude product is chromatographed on silica gel (125 ml) eluting with methanol/methylene chloride (2/98), the appropriate fractions are pooled and concentrated to give the title compound, mp 241°-242.5°; MS (m/z) at 350; IR (mineral off) 1641, 1506, 1658, 1409, 1417, 2237 (weak) cm-1 ; NMR (CDCl3) 1.83, 3.31, 4.36, 5.06, 7.12-7.30, 7.40, 7.49, 7.94 δ.

1. customAfter about 45 min a precipitate formed
2. customis partitioned between dichloromethane and aqueous sodium bicarbonate
3. dry with materialThe organic layers are dried over sodium sulfate
4. concentrationconcentrated
5. customThe crude product is chromatographed on silica gel (125 ml)
6. washeluting with methanol/methylene chloride (2/98)
7. concentrationconcentrated