木质素模型化合物香草醛Mannich反应及其产物化学结构表征

Mannich Reaction of Lignin Model Compound Vanillin and Chemical Structure Characterization of Its Product

摘要: 以木质素模型化合物香草醛、二乙醇胺及多聚甲醛为原料, 1,4-二氧杂环己烷为溶剂,通过Mannich反应合成了香草醛胺基多元醇,研究了物料配比、反应温度、时间及溶剂用量等因素对Mannich反应的影响。实验结果表明:反应物料按物质的量比n(香草醛):n(甲醛):n(二乙醇胺)1:1:1,甲醛与二乙醇胺 60℃ 反应 2 h 生成1,3-氧氮杂环戊烷,再将其滴入香草醛中, 80℃ 反应 3 h,二氧六环溶剂用量为 100 mL/mol(以香草醛的物质的量计),二乙醇胺的转化率最高可达到 84.92%。采用HPLC、 LC-MS、 FT-IR及 1H NMR 表征了香草醛胺基多元醇的化学结构,相对分子质量269。

Abstract: Vanillin aminated polyol(VAP) was prepared by vanillin, diethanolamine and paraformaldehyde in 1,4-dioxane by Mannich reaction. The effects of material ratio, reaction temperature, reaction time and solvent dosage on the Mannich reaction were investigated. It was observed the highest conversion rate of diethanolamine was up to 84.92% by dropping 1,3-oxazolidine which was the reaction product of formaldehyde and diethanolamine at 60℃ for 2 h, into vanillin and reacting at 80℃ for 3 h in the molar ratio of n(vanillin):n(formaldehyde):n(diethanolamine) as 1:1:1 in 1,4-dioxane of 100 mL/mol vanillin. The chemical structure of vanillin aminated polyol was characterized by HPLC, LC-MS, FT-IR and 1H NMR, respectively.