A new series of 2,5-disubstituted-1,3,4-thiadiazoles 6a-i was synthesized by overnight stirring various 1,4-disubstituted thiosemicarbazides 5a-i in polyphosphoric acid followed by neutralization. The structures of newly synthesized compounds 5a-i and 6a-i were characterized by IR, $^1H$ and $^13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were evaluated for their urease and acetylcholine esterase inhibition activities. Thiosemicarbazides 5a-i are found to possess excellent potential for urease inhibition, more than the standard drug. Thiosemicarbazides 5a-i are more potent urease inhibitor than their cyclic analogues thiadiazoles 6a-i. Almost all of the compounds are excellent inhibitors of acetylcholine esterase. The inhibition of acetylcholine esterase of compounds 5a, 5c, 5d, 5g, 5i, 6e, 6f, 6g, and 6i is much more than that of standard drug.
通过将各种 1,4-二取代的
硫代
氨基甲酸 5a-i 在多
磷酸中搅拌过夜并中和,合成了一系列新的 2,5-二取代-1,3,4-
噻二唑 6a-i。通过红外光谱、
$^1H$和
$^13}C$核磁共振、元素分析和质谱研究对新合成的化合物 5a-i 和 6a-i 的结构进行了表征。对所有合成化合物的
脲酶和
乙酰胆碱酯酶抑制活性进行了评估。研究发现,
硫代
氨基
脲 5a-i 具有比标准药物更强的抑制
脲酶的潜力。与环状类似物
噻二唑 6a-i 相比,
硫代
氨基
脲 5a-i 是更有效的
尿素酶
抑制剂。几乎所有化合物都是
乙酰胆碱酯酶的出色
抑制剂。化合物 5a、5c、5d、5g、5i、6e、6f、6g 和 6i 对
乙酰胆碱酯酶的抑制作用远高于标准药物。