对称性硫脲的绿色合成工艺

Green synthesis of symmetric thiourea compounds

摘要:

以乙二胺、CS 2 为原料、水为溶剂，一锅合成了亚乙基硫脲（ETU），收率和 HPLC 纯度均达到 99%以上。 利用 NMR、FTIR 对产物结构进行了确证。考察了 CS 2 滴加温度、乙二胺与 CS 2 物质的量比、回流反应温度、 回流反应升温速率及 NaOH 反应段 NaOH 用量对 ETU 收率、HPLC 纯度的影响。结果表明，ETU 的最佳合成工 艺条件为 CS 2 滴加温度 25~30 ℃、n(乙二胺)∶n(CS 2 )=1∶1.20、回流反应温度 65~70 ℃、回流反应升温速率 0.17 ℃/min、NaOH 反应段 NaOH 用量为乙二胺质量的 3.0%。以此工艺为模板，合成了 1,3-二乙基硫脲（DETU）和 四氢-2(1H)-嘧啶硫酮（PUR）。中试实验表明，该工艺稳定可靠，产品收率、HPLC 纯度均达到 99%以上，母液 可循环套用。

Abstract:

Ethylene thiourea (ETU), with both yield and HPLC purity over 99%, was synthesized with ethylenediamine and CS 2 as raw materials and water as solvent in one pot, and characterized by NMR and FTIR. The effects of CS 2 dropping temperature, molar ratio of ethylenediamine to CS 2 , reflux reaction temperature, reflux heating rate, and NaOH dosage in NaOH reaction section on the yield and purity of ETU were then investigated. The results showed that the optimum synthesis conditions were as follows: CS 2 dropping temperature of 25~30 ℃, n(ethylenediamine)∶n(CS 2 )=1∶1.20, reflux reaction temperature of 65~70 ℃, reflux heating rate of 0.17 ℃/min, and NaOH dosage in NaOH reaction section being 3.0% of the mass of ethylenediamine. 1,3-diethylthiourea (DETU) and tetrahydro-2(1H)-pyrimidine thioketone (PUR) were then synthesized under the optimized process conditions, and the pilot test indicated that the process was stable and reliable with the yield and HPLC purity of products obtained >99%, and the mother liquor could be recycled.