催化氧化法从重质松节油制高纯度长叶烯及环氧石竹烯

Preparation of Highly Pure Longifolene and β-Caryophyllene Epoxide from Heavy Turpentine via Catalytic Oxidation

摘要:

以过氧磷钼钨酸十六烷基吡啶盐（Cat-PMo2W2O24）为催化剂，质量分数30%H2O2为氧化剂，催化重质松节油中β-石竹烯氧化生成环氧石竹烯；产品经气质联用谱、红外光谱、1H及13C核磁共振谱的结构表征确证。考察了反应温度、溶剂种类、催化剂用量、反应物料比、反应时间对催化反应体系相态以及底物转化率与环氧选择性的影响，得出最优反应条件（重质松节油2.80g，催化剂用量为重质松节油质量的1.07%，溶剂乙酸乙酯5mL，H2O2与β-石竹烯的物质的量之比1.78，反应温度35℃，反应时间2.5h）。在此条件下，反应体系为环境友好液-液-固相转移催化反应体系，催化剂易分离回收、重复利用；β-石竹烯转化率和环氧石竹烯选择性分别高达98.1%和98.4%，而长叶烯基本不被氧化；反应结束后，反应混合物经冷却相分离除去水相，过滤回收催化剂，减压分馏得到高纯度长叶烯（GC含量>92%）和环氧石竹烯(GC含量>95%)。

Abstract:

Oxidation of β-Caryophyllene in heavy turpentine to β-caryophyllene epoxide in presence of mass fraction 30 % H2O2 aqueous solution by using peroxyphosphotungstomolybdate cetylpyridinium (Cat-PMo2W2O24 ) as catalyst was firstly reported. The product was structurally identified by means of GC/MS, IR, 1H NMR, and 13C NMR. The reaction parameters such as reaction temperature, solvent type, amounts of catalyst, material ratio, and reaction time, had obvious effect on the phase state of the reaction system, the conversion of β-caryophyllene and the selectivity of β-caryophyllene epoxide. An environment-friendly liquid-liquid-solid phase transfer catalytic system was constructed by using ethyl acetate as solvent in which the catalyst could easily be recycled. Under optimum conditions( based on the heavy turpentine mass of 2.80g,the catalyst dosage of 1.07%,the solvent volume of 5mL,n(H2O2 ): n(β-caryophyllene) = 1.78,the reaction temperature of 35℃,the reaction time of 2.5h), the conversion of β-caryophyllene and the selectivity of β-caryophyllene epoxide were up to 98.1% and 98.4% respectively, but the conversion of longifolence has hardly been found. After reaction, the reaction mixture was cooled to remove aqueous phase by phase separation and collect the catalyst by only a simple filtration, and then longifolence and β-caryophyllene epoxide are separated from the filtration by vacuum fractionation with purity(GC) greater than 90% and 95%, respectively.