Regioselectivity of electrophilic attack on 4-methyl-1-thioxo-1,2,4,5-tetrahydro[1,2,4]triazolo[4,3-a]quinazolin-5-one - Part 2: Reactions on nitrogen atom
Regioselectivity of electrophilic attack on 4-methyl-1-thioxo-1,2,4,5-tetrahydro[1,2,4]triazolo[4,3-a]quinazolin-5-one - Part 2: Reactions on nitrogen atom
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DOI：
10.3390/51201210
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发表时间：
2000-12-01
期刊：
影响因子：
4.6
通讯作者：
Pazdera, P
中科院分区：
文献类型：
--
作者：
Fathalla, W;Cajan, M;Pazdera, P
以4-甲基-1-硫代-1，2，4，5-四氢[1，2，4]三唑并[4，3-a]喹唑啉-5-酮1为模型化合物，研究了环硫代酰胺基团对不同亲电试剂的区域选择性。化合物1在甲醛、酰卤和具有活化双键的化合物存在下与卤代烷、胺反应，得到N-取代衍生物2、3和6。氮原子上的区域选择性反应是由于强烈的库仑吸引力。在过氧化氢的存在下，1与胺反应得到氨解产物4。化合物1-6通过FTIR、1H MMR、13 C NMR和质谱鉴定。
The regioselectivity on a cyclic thioamide group towards different electrophiles was studied on the model compound 4-methyl-1-thioxo-1,2,4,5-tetrahydro[1,2,4]triazolo [4,3-a]quinazolin-5-one 1. The examined compound 1 reacts with alkyl halides, amines in the presence of formaldehyde, acyl halides and compounds having activated double bonds to afford the N-substituted derivatives 2, 3 and 6. The regioselective reactions on nitrogen atom are due to strong Coulombic attraction. The reaction of 1 with amines in the presence of hydrogen peroxide afforded the aminolysis product 4. Compounds 1-6 were identified by FTIR, 1H MMR, 13C NMR, and mass spectroscopy.