[NH:1]([C:3]([C:5]1[NH:6][CH:7]=[CH:8][N:9]=1)=[O:4])[NH2:2].[CH3:10]OC(OC)N(C)C.C(OCC)C>C1C=CC(C2C=CC=CC=2)=CC=1.C1C=CC(OC2C=CC=CC=2)=CC=1>[N:6]1[CH:7]=[CH:8][N:9]2[C:5]=1[C:3](=[O:4])[NH:1][N:2]=[CH:10]22-Hydrazinocarbonylimidazole (prepared according to the procedure described in EP-A-0713876) (1.00 g, 7.93 mmol) was suspended in Dowtherm A (6 ml), N,N-dimethylformamide dimethyl acetal (1.89 g, 15.9 mmol) added and the mixture heated at 100° C. for 1.5 h then at 210° C. for 18 h. The mixture was allowed to cool to room temperature, diethyl ether (100 ml) added and the precipitated solid was filtered. The brown solid was purified by dry flash column chromatography on silica eluting with dichloromethane (+0.1% 0.880 ammonia) on a gradient of methanol (5-12%). Collecting appropriate fractions gave 7H-imidazo[1,2-d][1,2,4]triazin-8-one (216 mg, 20%) as an off-white solid: δH (400 MHz, CDCl3) 7.59 (1H, d, J 1), 7.91 (1H, d, J 1), 8.74 (1H, s), 12.39 (1H, s).
Loading…
