1,1,3,3-Tetramethylguanidine → Methyl 3-(4-(6-(5,7-dimethoxy-4-oxo-3,4-dihydroquinazolin-2-yl)pyridin-2-yl)piperazin-1-yl)propanoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred suspension of methyl 3-(piperazin-1-yl)propanoate dihydrochloride (0.358 g, 1.46 mmol) and 2-(6-fluoropyridin-2-yl)-5,7-dimethoxyquinazolin-4(3H)-one (0.220 g, 0.73 mmol) in dry DMSO (1.5 mL) was added 1,1,3,3-tetramethylguanidine (0.336 g, 2.92 mmol). The resulting mixture was heated at 85° C. for 5 h. After that time the reaction was cooled to rt, diluted with water (20 mL) and extracted with ethyl acetate (3×25 mL). The organic phase was washed with water and brine, dried over sodium sulfate, filtered and concentrated under reduced pressure. The product was purified by flash column chromatography (silica gel, 99:1 dichloromethane/methanol to 97:3 dichloromethane/methanol) to give methyl 3-(4-(6-(5,7-dimethoxy-4-oxo-3,4-dihydroquinazolin-2-yl)pyridin-2-yl)piperazin-1-yl)propanoate (0.220 g, 66%) as an off-white solid: 1H NMR (400 MHz, CDCl3) δ 10.31 (s, 1H), 7.85 (d, J=7.42 Hz, 1H), 7.62-7.70 (m, 1H), 6.79-6.85 (m, 2H), 6.48 (d, J=2.34 Hz, 1H), 3.99 (s, 3H), 3.94 (s, 3H), 3.72 (s, 3H), 3.59-3.67 (m, 4H), 2.75-2.83 (m, 2H), 2.54-2.66 (m, 6H); ESI MS m/z 454 [M+H]+.

Herkunft & Nachweise