脱氢乙酸合成2,6-二甲基-γ-吡喃酮工艺研究

2,6-Dimethyl-γ-pyranon synthetized by dehydroacetic acid

研究了脱氢乙酸制备标题化合物的合成方法与提取工艺。采用单因素试验考察了酸的种类与浓度、催化剂种类与用量、油浴温度与反应时间对反应产率的影响,得到的较佳工艺条件为:以杂多酸H4PW11VO40为催化剂、m(脱氢乙酸)∶m(H4PW11VO40)=5.5∶1,采用盐酸为反应介质、质量浓度为37.5%,油浴温度95℃,反应时间6 h,反应以脱氢乙酸计的产率为96.2%;对反应液进行了提取工艺研究,考察了萃取剂种类、溶液pH和盐析效应等对产物收率和含量的影响。采用HPLC分析了产物的纯度,其质量含量99%以上,收率85.4%,并利用红外光谱、核磁共振氢谱对产物的结构进行了表征。

The synthesis method and extract process during preparation of 2, 6-dimethyl-γ-pyranon from dehydroacetic acid was researched. The effect of acid＇s type and concentra- tion,catalyst＇s type and the consumption, reaction time and reaction temperature on the yield was investigated by single factor experiments, and the optimized conditions were： H4 PW11 VO40 as catalyst, m （ dehydroacetic acid） ： m （ H4 PW11 VO460） = 5.5： 1, hydrochloric acid as reaction medium and the mass concentration was 37.5% ,oil bath temperature was 95 ℃ , reaction time was 6 h. The yield of 2,6-dimethyl-γ- pyranon could reach 96.2%. The extract process of reaction liquid was obtained,the effect of extractants＇ type,pH of liquid, salt effect,etc on the yield was investigated. The product was confirmed by FT-IR and ^1HNMR,the yield was 85.4% and its mass concentration was above 99%.