摘要
对CLY纳米催化剂催化α 蒎烯酯化-皂化法合成龙脑进行了研究。首先α 蒎烯和无水草酸在CLY纳米催化剂作用下发生酯化反应生成草酸龙脑酯;然后加入氢氧化钠溶液发生皂化反应,水蒸气蒸馏收集龙脑。酯化反应时间为 6h,采用程序升温方式(65℃ 1h, 75℃ 4h, 90℃ 1h),原料最佳配比n(α 蒎烯)∶n(草酸) =1∶0 4。皂化反应并收集龙脑约 1h,n(草酸龙脑酯)∶n(氢氧化钠) =1∶5。在上述反应条件下,当CLY2催化剂质量为α 蒎烯质量的 6%时,龙脑产率 93 3%,m(正龙脑)∶m(异龙脑) =29 1∶62 3;当CLY4催化剂质量为α 蒎烯质量的 2%时,产率为 46 0%,m(正龙脑)∶m(异龙脑) =70 5∶7 3,通过柱层析分离可获得质量分数为 98 9%的正龙脑。催化剂经 5次再生使用,产率仅下降 8 7%,而产品中正龙脑质量分数上升 2 2%,可见催化剂经再生可重复使用。
Borneol could be synthesized from α-pinene by esterification-saponification method in the presence of CLY nanometer catalyst.Firstly,bornyl oxalate was formed by esterification of α-pinene with anhydrous oxalic acid using CLY as catalyst.Secondly,borneol was obtained from bornyl oxalate by saponification with NaOH solution.Esterification was conducted under programmed heating temperature (65 ℃ 1 h,75 ℃ 4 h,90 ℃ 1 h),and the best mole ratio of α-pinene to oxalic acid was 1∶0.4.The time of saponification and collection of borneol was 1 hour with bornyl oxalate and NaOH in mole ratio 1∶5.When the use level of CLY2 catalyst was 6% of the mass of α-pinene,the yield of product reached 93.3%,but the mass ratio of borneol to isoborneol in the product was 29.1∶62.3.When CLY4 was used as the catalyst to synthesize borneol and its addition was 2% of the mass of α-pinene,the yield of product was 46.0%,and the mass ratio of borneol to isoborneol in the product could reach 70.5∶7.3.After separation by column chromatography,borneol with high purity 〔w(borneol)=98.9%〕 was obtained.When the catalyst which had been used four times was used to prepare borneol,the yield of product decreased by 8.7% and the borneol content in product rised by 2.2% as compared with the first time.The results showed that catalysts could be reused after activation.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2005年第4期277-279,共3页
Fine Chemicals
基金
国家自然科学基金资助项目(20262002)
江西省自然科学基金资助项目(0420016)~~
