Synthesis of 5-substituted-1H-tetrazole derivatives from aryl aldehydes under the influence of Palladium nanoparticles entrapped in aluminum hydroxide matrix (Pd/AlO(OH) NPs) was carried out in ethanol for 3-6 h. The use of the catalyst in this synthesis is the first. Sodium azide and malononitrile used in the reaction are chemical compounds required in the synthesis of tetrazoles. The reactions were concluded with good yields under thermal conditions. In the reactions, twelve derivatives were synthesized. The synthesized compounds were characterized by IR, ¹H, and ¹³C NMR. The olefinic proton's signal, which is around 8.5 ppm, reveals the formation of the tetrazole ring. The tyrosinase enzyme activity for each synthesized derivative was examined, and the results were recorded. According to the results obtained, all tetrazole derivatives were found to be effective compounds for tyrosinase enzyme inhibition. 3-(3,4-dichlorophenyl)-2-(1H-tetrazol-5-yl)acrylonitrile (2k) with two chloride groups at the meta and para position of the phenyl ring seems to be the most potent tyrosinase inhibitor with an IC₅₀ value of 45 µM.

Graphical abstract

中文翻译：

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含Pd纳米粒子合成的5-取代-1H-四唑衍生物对酪氨酸酶的功效研究

在氢氧化铝基质（Pd/AlO(OH) NPs）中包埋的钯纳米颗粒的影响下，在乙醇中合成 5-取代-1H-四唑衍生物，反应时间为 3-6 小时。该合成中催化剂的使用是首次。反应中使用的叠氮化钠和丙二腈是合成四唑所需的化合物。反应在热条件下以良好的收率结束。在反应中，合成了十二种衍生物。合成的化合物通过IR、^1H、^13C NMR 进行了表征。烯烃质子的信号约为 8.5 ppm，揭示了四唑环的形成。检查每种合成衍生物的酪氨酸酶活性，并记录结果。根据所获得的结果，发现所有四唑衍生物都是抑制酪氨酸酶的有效化合物。苯环间位和对位有两个氯基的 3-(3,4-二氯苯基)-2-(1H-四唑-5-基)丙烯腈 (2k) 似乎是最有效的酪氨酸酶抑制剂，具有 IC 值₅₀值为 45 µM。

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