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 NMR, 13C NMR, and mass spectroscopy.
在模型化合物4-甲基-1-
硫酮-1,2,4,5-四氢[1,2,4]三唑并[4,3-a]喹唉-5-酮1上研究了环状
硫酰胺基团对不同亲电试剂的区域选择性。考察的化合物1与烷基卤化物、在
甲醛存在下的胺、酰基卤化物以及具有活化双键的化合物反应,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
过氧化氢存在下,化合物1与胺反应得到胺解产物4。化合物1至6通过FTIR、1H NMR、13C NMR和质谱法进行鉴定。