离子液体中芳基噻唑腙甲酸酯类化合物的合成

Synthesis of aryl thiazolyl-hydrazone formate catalyzed by ionic liquid

以间甲基苯胺和硫氰酸铵为起始原料,合成得到芳基硫脲1,再与3-溴-2,4-戊二酮2反应得到2-芳基-4-甲基-5-噻唑乙酮3,后者在离子液体N-乙基吡啶硫酸氢盐4催化下与肼基甲酸甲酯反应,生成目标化合物芳基噻唑腙甲酸酯5。探讨了反应物配比、反应时间、催化剂种类、催化剂用量及重复利用次数对目标化合物收率的影响。结果表明,以N-乙基吡啶硫酸氢盐为催化剂,反应物配比为1∶1.1,控制反应时间为6h及反应温度为82℃,目标化合物收率可达31.1%,催化剂经处理后重复利用4次,收率仍可达30.3%。产品的结构经元素分析、IR、~1H NMR及MS确证。

The phenylthiourea 1 was prepared from m-toluidine and ammonium sulfocyanide as primary materials.2-Aryl-4-methyl-5-thiazole acetophenone 3 was obtained by the reaction of compound 1 with 3-bromo-2,4-pentanedione 2. In the presence of N-ethylpyridinium bisulfate 4,the compound 5 was synthesized by compound 3 and methyl hydrazinecarboxylate.The effects of reagent ratio,reaction time,catalyst type,catalyst amount and reusability were discussed.The results showed that the yield of compound 5 was31. 1%under the conditions of reagent ratio 1 ∶ 1. 1,reaction time 6h with compound 4 as catalyst at 82℃. The yield of target compound 5 was about 30. 3%when the catalyst was employed after 4 runs. The structure of product was confirmed by elemental analysis,IR,~1H NMR and MS.