[NH:1]1[C:5]([C:6]2[C:11](=[O:12])[N:10]3[CH:13]=[CH:14][CH:15]=[CH:16][C:9]3=[N:8][CH:7]=2)=[N:4][N:3]=[N:2]1.C(=O)([O-])[O-].[K+].[K+].Cl[C:24]([O:26][CH3:27])=[O:25]>CN(C)C=O>[CH3:27][O:26][C:24]([N:1]1[C:5]([C:6]2[C:11](=[O:12])[N:10]3[CH:13]=[CH:14][CH:15]=[CH:16][C:9]3=[N:8][CH:7]=2)=[N:4][N:3]=[N:2]1)=[O:25]A mixture of 1.07 g (0.005 moles) of 3-(1H-tetrazol-5-yl)-4-oxo-4H-pyrido[1,2-a]pyrimidine; 45 ml of dimethylformamide, 0.75 g (0.0055 moles) of anhydrous potassium carbonate and 0.76 ml (0.01 moles) of methyl chloroformate was stirred at 80°-90° C. for 6 hours. The hot reaction mixture was filtered; the crystals precipitating from the filtrate were collected to obtain 0.32 g (23.5%) of the 1:1 ratio mixture of the title compounds, which on crystallization from ethanol gave the 3-(1-methoxycarbonyl-1H-tetrazol-5-yl)-4-oxo-4H-pyrido[1,2-a]pyrimidine, m.p.: 182°-183° C.
Wird geladen…
