2-Ethyl-3-oxazolidineethanol (OE) is an important pharmaceutical intermediate for the treatment of dental plaque. A systematic investigation of the one-pot synthesis of OE from propanal (PA) and diethanolamine (DEA) was conducted herein. The process was carried out under mild reaction conditions without any addition of catalyst, and the product was characterized by Fourier transform infrared spectroscopy (FT-IR), ¹H nuclear magnetic resonance (NMR), and electrospray ionization-tandem mass spectrometry (ESI-MS/MS). Additionally, the effects of the PA/DEA ratio, methanol/DEA ratio, reaction time, and temperature on the reaction results were explored. Based on the single-factor experiments, response surface methodology (RSM) was used to optimize the reaction conditions and it achieved a high OE yield of 98.48%, which is close to the prediction value of 98.38%. Furthermore, the reaction kinetics were calculated utilizing the second-order kinetic model, and activation energies of the forward and reverse reactions were 31.35 and 41.85 kJ·mol^–1, respectively. Under the optimization reaction conditions, OE was efficiently synthesized, indicating a significant potential for industrial applications.

中文翻译：

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从丙醛和二乙醇胺合成 2-乙基-3-恶唑烷乙醇：动力学和工艺优化研究

2-乙基-3-恶唑烷乙醇 (OE) 是治疗牙菌斑的重要药物中间体。本文对从丙醛 (PA) 和二乙醇胺 (DEA) 一锅法合成 OE 进行了系统研究。该过程在温和的反应条件下进行，不添加任何催化剂，并通过傅里叶变换红外光谱 (FT-IR) 对产物进行表征，¹H 核磁共振 (NMR) 和电喷雾电离串联质谱 (ESI-MS/MS)。此外，探讨了 PA/DEA 比率、甲醇/DEA 比率、反应时间和温度对反应结果的影响。在单因素实验的基础上，采用响应面法（RSM）优化反应条件，获得了98.48%的高OE产率，接近98.38%的预测值。此外，利用二级动力学模型计算反应动力学，正逆反应的活化能分别为31.35和41.85 kJ·mol ^–1。在优化的反应条件下，OE被高效合成，具有巨大的工业应用潜力。