反应详情

A solution of 2-(4-methoxybenzyl)-7-(pyrimidin-4-ylamino)-3,4-dihydro-1H-pyrido[1,2-a]pyrazine-1,6(2H)-dione (5, 0.3 g, 0.79 mmol) in trifluoroacetic acid (5 mL) was heated at 90° C. for 48 h. The reaction mixture was cooled to room temperature and concentrated under reduced pressure. The residue was neutralized with saturated solution of sodium bicarbonate and the compound was extracted in 10% methanol in ethyl acetate. The organic layer was separated, dried over sodium sulphate, concentrated under reduced pressure and the residue obtained was purified via column chromatography (silica, methanol/dichloromethane=10%) to afford 7-(pyrimidin-4-ylamino)-3,4-dihydro-1H-pyrido[1,2-a]pyrazine-1,6(2H)-dione (Cpd. No. 1) as a beige solid. Yield: 0.12 g, 59%; MS (ESI) m/z 258 [M+1]+; 1H NMR (400 MHz, DMSO-d6) δ 9.45 (s, 1H), 8.79-8.64 (m, 2H), 8.48 (s, 1H), 8.38 (d, J=5.9 Hz, 1H), 7.41 (dd, J=6.0, 1.3 Hz, 1H), 7.11 (d, J=7.9 Hz, 1H), 4.23-4.16 (m, 2H), 3.55-3.48 (m, 2H).

1. concentrationconcentrated under reduced pressure
2. extractionthe compound was extracted in 10% methanol in ethyl acetate
3. customThe organic layer was separated
4. dry with materialdried over sodium sulphate
5. concentrationconcentrated under reduced pressure
6. customthe residue obtained
7. customwas purified via column chromatography (silica, methanol/dichloromethane=10%)