Synthesis Research Of Thymol And Its Derivatives

The thymol and their derivatives have special aroma. Except to be used for flavoring industry, their good biological activity also have wide application in medical treatment. In the study, m-cresol and isopropyl alcohol are used as the raw material. Thymol is synthesized by Fu Ke-alkylation reaction under microwave radiation. The suitable conditions obtained by single factor experiment are as follow: the solid super acid SO42-/Zr O2-Ti O2 is used as catalyst, n(m-cresol) : n(isopropyl alcohol) = 1 : 5, reaction time is 15 min, the dosage of the catalyst is 8% of the raw material m-cresol, microwave heating power is 600 W, reflow reaction temperature. In above conditions, the product yield was 59.2%. The product identified by FT-IR, GC-MS and 1H NMR was thymol.The thymol is used as raw material. Under ultrasonic radiation, 4-((dimethylamino)methyl)-2-isopropyl-5-methylphenol is synthesized by Mannich reaction. The suitable conditions obtained by single factor experiment are as follow: nitric acid is used as catalyst, solvent is methanol, n(thymol) : n(nitric acid) : n(dimethylamine) : n(methanal) = 1: 3.5 : 3 : 3, reaction time is 30 min, reaction temperature is 50℃. Under the conditions, the product yield was 79.9%. The product was identified by FT-IR, GC-MS and 1H NMR.The thymol is used as raw material. Under microwave radiation, 4-bromothymol is synthesized by bromine generation reaction. The suitable conditions obtained by single factor experiment are as follow: bromine generation agent is N-butyl bromide generation diimide, solvent is acetic acid, n(thymol) : n(bromine generation agent) = 1 : 1.5, reaction time is 15 min, reaction temperature is 20℃, microwave heating power is 500 W. Under the condition, the product yield was 65.1%. The structure of the product was identified by FT-IR, GC-MS and 1H NMR.The thymol and bromine generation of n-butane are used as raw material. 2-butoxy-1-isopropyl-4-methylbenzene is synthesized by etherification reaction. The suitable conditions obtained by single factor experiment are as follow: tetrabutyl ammonium bromide is used as catalyst, n(thymol) : n(tetrabutyl ammonium bromide)= 1: 0.4, n(thymol) : n(bromine generation of n-butane) = 1 : 1.2, reaction time is 3 h, reaction temperature is 90 ℃. Under the condition, the product yield was 94.2%. The product was identified by FT-IR, GC-MS and 1H NMR.