脱氢芳樟醇减压精馏过程形成的杂质结构表征

Structure characterization of primary impurity formed in the rectification process of dehydrolinalool under vacuum condition

以质量分数为97.2%的脱氢芳樟醇为原料,198～202℃、常压条件下进行热环化反应,反应时间7.5 h,得到质量分数为94.0%的1-甲基-2-亚甲基-3-异丙烯基-1-环戊醇顺反异构体混合物,以GC/IR、GC/MS、1H NMR、13C NMR、HSQC技术对自制的1-甲基-2-亚甲基-3-异丙烯基-1-环戊醇样品进行表征。考察了温度对脱氢芳樟醇热环化反应影响,以自制1-甲基-2-亚甲基-3-异丙烯基-1-环戊醇标样进行比对分析,结合脱氢芳樟醇精馏产品杂质的GC/MS谱图,确定脱氢芳樟醇减压精馏过程形成的主要杂质是1-甲基-2-亚甲基-3-异丙烯基-1-环戊醇顺反异构体混合物,是由脱氢芳樟醇精馏过程中发生热环化反应形成的。

Thermal cyclization of dehydrolinalool with 97.2 mass percent at 198—202 ℃ under the condition of atmospheric pressure for 7.5h gave the product containing of 94.0 mass percent of cis and trans isomers of 1-methyl-2-methylidene-3-isopropenyl-1-cyclopentanol which were characterized by GC-MS,GC-IR,13C NMR,HSQC and 1H NMR spectroscopy.Effect of temperature on the thermal cyclization of dehydrolinalool was investigated.Based on the analytical data of the sample of 1-methyl-2-methylidene-3-isopropenyl-1-cyclopentanol prepared as above and impurities tested by GC/MS spectra in dehydrolinalool,it showed that the primary impurities formed in the rectification process of dehydrolinalool under vacuum condition are cis and trans isomers of 1-methyl-2-methylidene-3-isopropenyl-1-cyclopentanol.