Method 1: Take 100 grams of D-alpha tocopherol, blend it with 300 grams of n-hexane and 4 grams of zinc chloride, manage the temperature to 35 ° C, slowly add acetic anhydride dropwise into the reaction pot, execute esterification for 2 hours, wash with water, and concentrate., get the crude item of D-alpha-tocopherol acetate, then mix the unrefined product with 400 grams of ethanol, put it on the column, manage the flow rate and temperature level of the column to 20-50 ° C, and adsorb it through D-101 macroporous adsorption material, and the effluent Concentrate and desolubilize, then mix the concentrated service with 400 grams of ethanol, include 5 grams of triggered carbon, usage external blood circulation at a continuous temperature of 60 ° C for 2 hours, filter and concentrate, and after that filter and concentrate the focused option under high vacuum cleaner conditions. Short-range molecular purification and improvement are made use of to obtain the finished item of D-alpha-tocopheryl acetate. The determined web content of D-alpha-tocopheryl acetate is 98.3%; specific optical rotation +24.2 °; heavy metal (determined as Pb) 9.5 ppm; benzopyrene ≤ 2ppb.
Approach 2. A preparation approach of natural vitamin E, including the adhering to steps:
( 1) Preparation of d-α-tocopherol
a. Take the adhering to basic materials by weight, mix 1.5 parts of tocopherol, 4-6 parts of isopropyl ether, 2-4 parts of hydrochloric acid, 0.5-1.5 parts of stannous chloride, 0.5-1.5 parts of acetic acid, and 0.5-1.5 parts of formaldehyde, Add the above resources into the reaction kettle, mix, raise the temperature to 50-70 ° C, regulate the temperature level to 50-70 ° C and react for 5 hours, after that stop the response;
b. After cooling to room temperature level, stall, different the reduced liquid phase, include detoxified water to the natural phase for cleaning, get rid of the aqueous phase, include anhydrous salt sulfate to the natural stage and completely dry for 2 hours, filter, and wash the filter cake with isopropyl ether., obtain the washing fluid, integrate the filteringed system filtrate and the cleaning liquid to get the total filtrate, and evaporate the solvent under minimized pressure listed below 50 ° C to obtain d-α-tocopherol;( 2) Prep work of d-α-tocopheryl acetate a. Add 1.3 parts by weight of d-α-tocopherol, 2-4 components by weight of cyclohexane, and 0.5-1.5 parts by weight of acetic anhydride into the response kettle, raise the temperature to 70-90 ° C, and maintain it cozy for 5 hours prior to stopping. response;
b. After cooling to area temperature level, include detoxified water for washing, remove the water stage, and focus the natural stage under minimized pressure below 50 ° C to obtain d-α-tocopheryl acetate;( 3 )Molecular distillation a. Degassing: Include d-α-tocopheryl acetate into the raw product container to pre-heat, utilize a metering pump to drive into the degassing scrape, and warmth and degas under a vacuum of 500Pa to obtain the degassed unrefined product; b. Eliminate low boiling point raw material: make use of an equipment pump to pump the degassed crude item right into the molecular distillation phase, conduct heating and purification under a vacuum of 300 Pa, and recuperate and refine the low boiling point raw material to get the low boiling point crude item; c. Pre-removal fraction: Utilize an equipment pump to pump the unrefined item of low-boiling matter right into the second stage of molecular distillation, and conduct home heating and distillation at a vacuum cleaner of 200Pa to obtain the unrefined distillation product; d. Purification products: Utilize an equipment pump to pump the unrefined purification item into the 3rd stage of molecular purification, and carry out distillation under a vacuum of 100Pa. The product acquired by distillation is all-natural vitamin E.