ピラツォロン誘導体の合成研究(第20報)4-Bromo-3-(2-formamidophenyl)-thiomethyl-2-methyl-1-phenyl-3-pyrazolin-5-oneの閉環反応について

抄録

The Ullmann reaction of 4-bromo-3-(2-formamidophenyl)thiomethyl-2-methyl-1-phenyl-3-pyrazolin-5-one (IV) in an aprotic dipolor solvent such as dimethylformamide gave a five-membered ring compound 3-(3-formamidobenzothiazol-2-yl)-2-methyl-1-phenyl-3-pyrazolin-5-one (VII). Hydrolysis of VII in 10% HCl-EtOH (1 : 1) save 3-(2-benzothiazolyl)-2-methyl-1-phenyl-3-pyrazolin-5-one (III) . However, the Ullmann reaction of IV in a nonrolar solvent such as xylene afforded a seven-membered ring compound, 4-formyl-1-methyl-2-phenyl-1, 2, 3, 10-tetrahydro-4H-pyrazolo[3, 4-c][1, 5]benzothiazepin-3-one (XI). Hydrolysis of XI in 10% HCl-EtOH (1 : 1)gave 1-methyl-2-phenyl-1, 2, 3, 10-tetrahydro-4H-pyrazolo[3, 4-c][1, 5]benzothiazepin-3- one (I). The Ullmann reaction of 4-substituted-3-(2-acylamido-4-substituted phenyl)-thiomethyl-2-methyl-1-phenyl-3-pyrazolin-5-ones was studied in various solvents. The structure of III was proved by its synthesis by other routes.