Background: Urea, thiourea, and 1,2,4-oxadiazole compounds are of great interest due to their different activities such as anti-inflammatory, antiviral, analgesic, fungicidal, herbicidal, diuretic, antihelminthic and antitumor along with antimicrobial activities.

Objective: In this work, we provide a new series of potential biologically active compounds containing both 1,2,4-oxadiazole and urea/thiouprea moiety.

Materials and Methods: Firstly, 5-chloromethyl-3-aryl-1,2,4-oxadiazoles (3a-j) were synthesized from the reaction of different substituted amidoximes (2a-j) and chloroacetyl chloride in the presence of pyridine by conventional and microwave-assisted methods. In the conventional method, 1,2,4-oxadiazoles were obtained in two steps. O-acylamidoximes obtained in the first step at room temperature were heated in toluene for an average of one hour to obtain 1,2,4-oxadiazoles. The yields varied from 70 to 96 %. 1,2,4-oxadiazoles were obtained under microwave irradiation in a single step in a 90-98 % yield at 160 °C in five minutes. 5-aminomethyl-3-aryl-1,2,4- oxadiazoles (5a-j) were obtained by Gabriel amine synthesis in two steps from corresponding 5-chloromethyl-3- aryl-1,2,4-oxadiazoles. Finally, twenty new urea (6a-j) and thiourea (7a-j) compounds bearing oxadiazole ring were synthesized by reacting 5-aminomethyl-3-aryl-1,2,4-oxadiazoles with phenyl isocyanate and isothiocyanate in tetrahydrofuran (THF) at room temperature with average yields (40-70%).

Results and Discussions: An efficient and rapid method for the synthesis of 1,2,4-oxadiazoles from the reaction of amidoximes and acyl halides without using any coupling reagent under microwave irradiation has been developed, and twenty new urea/thiourea compounds bearing 1,2,4-oxadiazole ring have been synthesized and characterized.

Conclusion: We have synthesized a new series of urea/thiourea derivatives bearing 1,2,4-oxadiazole ring. Also facile synthesis of 3,5-disubstituted 1,2,4-oxadiazoles from amidoximes and acyl chlorides under microwave irradiation was reported. The compounds were characterized using FTIR, 1H NMR, 13C NMR, and elemental analysis techniques.

背景：尿素、硫脲和 1,2,4-恶二唑化合物由于具有不同的活性，如抗炎、抗病毒、镇痛、杀真菌、除草、利尿、抗蠕虫和抗肿瘤以及抗菌活性而备受关注。

目的：在这项工作中，我们提供了一系列新的潜在生物活性化合物，其中包含 1,2,4-恶二唑和尿素/硫脲部分。

材料与方法：首先，在吡啶存在下，由不同取代的脒(2a-j)与氯乙酰氯反应合成5-氯甲基-3-芳基-1,2,4-恶二唑(3a-j)。和微波辅助方法。在常规方法中，1,2,4-恶二唑分两步获得。将第一步得到的O-酰氨基肟在室温下在甲苯中加热平均1小时，得到1,2,4-恶二唑。产率从 70% 到 96% 不等。1,2,4-恶二唑在微波辐射下一步获得，在 160 °C 下，5 分钟内产率为 90-98%。5-氨基甲基-3-芳基-1,2,4-恶二唑(5a-j)是通过Gabriel胺合成从相应的5-氯甲基-3-芳基-1,2,4-恶二唑分两步获得的。最后，

结果与讨论：已开发出一种在微波辐射下不使用任何偶联剂而由脒肟和酰卤反应合成 1,2,4-恶二唑的高效、快速方法，并开发了 20 种新型尿素/硫脲化合物，其中含有 1,已经合成并表征了2,4-恶二唑环。

结论：我们合成了一系列新的带有1,2,4-恶二唑环的脲/硫脲衍生物。还报道了在微波辐射下从偕胺肟和酰氯轻松合成 3,5-二取代的 1,2,4-恶二唑。使用 FTIR、1H NMR、13C NMR 和元素分析技术对化合物进行表征。