A facile synthesis of 3-substituted 2-cyanoquinazolin-4(3<i>H</i>)-ones and 3-alkyl-2-cyanothieno[3,2-<i>d</i>]pyrimidin-4(3<i>H</i>)-ones<i>via</i>1,2,3-dithiazoles
作者:Hyi-Seung Lee、Yong-Goo Chang、Kyongtae Kim
DOI:10.1002/jhet.5570350327
日期:1998.5
displaced by various nucleophiles to give 2-substituted quinazolinones 11–19, which indicates that compounds 5 can be utilized as starting materials for the synthesis of new 2-substituted quinazolines. Similarly 3-alkyl-2-cyanomieno[3,2,-d]pyrimidin-4(3H)-ones 22 were prepared from methyl 3-[N-(4-chloro-5H-1,2,3-dimiazol-5-ylidene)]-2-thiophencarboxylate (21) in moderate to good yields.
邻氨基苯甲酸甲酯与4,5-二氯-1,2,3- dithiazolium酰氯(阿佩尔氏盐)在室温下的二氯甲烷吡啶(2个当量)的存在下反应,得到甲基ñ - (4-氯-5- ħ - 1,2,3- dithiazol -5-亚基)邻氨基苯甲酸(3A)(50%产率),其与空间位较少反应阻的伯烷基胺,得到直接3-烷基-2- cyanoquinazolin-4(3 ħ) -酮5中中等至良好的产量。与叔丁胺,N-(2-甲氧基羰基苯基)亚氨基氰甲基N-(叔丁基)二硫化物7和2-(N-氰基硫代甲酰氨基)邻氨基苯甲酸甲酯(分离得到的8)的产率分别为33%和59%。喹唑啉5a(R = CH 3)的氰基很容易被各种亲核试剂取代,得到2-取代的喹唑啉酮11-19,这表明化合物5可用作合成新的2-取代的喹唑啉的原料。同样3-烷基-2- cyanomieno [3,2, - d ]嘧啶-4(3 H ^) -酮22,从甲基3-制备[