[CH3:1][O:2][C:3]1[CH:11]=[C:10]([S:12][CH3:13])[CH:9]=[CH:8][C:4]=1[C:5]([OH:7])=O.[NH2:14][C:15]1[NH:16][C:17](=[O:23])[NH:18][C:19](=[O:22])[C:20]=1[NH2:21].O>CN(C)C=O>[NH2:14][C:15]1[NH:16][C:17](=[O:23])[NH:18][C:19](=[O:22])[C:20]=1[NH:21][C:5](=[O:7])[C:4]1[CH:8]=[CH:9][C:10]([S:12][CH3:13])=[CH:11][C:3]=1[O:2][CH3:1]Twenty grams of 2-methoxy-4-methylmercapto-benzoic acid is dissolved in 260 ml of dimethylformamide, mixed with 13 gm of N,N'-carbonyl-diimidazole, and stirred for 30 minutes at ambient temperature. Then, 13 gm of 4,5-diamino-pyrimidin-2,6-dione are added, and the reaction mixture is refluxed for three hours with stirring. After cooling, it is poured into 1 liter of water. The product precipitated is suction filtered, washed with water, and dried at 70° C. in a circulating air drier.
불러오는 중…