Anisaldehyde is also known as p-methoxybenzaldehyde, 4-methoxybenzaldehyde, p-anisaldehyde, and anisaldehyde. It is a colorless to light yellow transparent liquid at room temperature. There is a strong aroma like anise and hawthorn. The melting point is 2.5℃, the boiling point is 247~248℃, and the flash point is 121℃. Miscible in grease, soluble in ethanol (1ml dissolved in 3mL 60% ethanol, transparent), ether, acetone, chloroform, etc., slightly soluble in propylene glycol and glycerin. Slightly soluble in water (0.3%), can evaporate with water vapor, almost insoluble in mineral oil. Unstable in alkaline conditions. Natural products are found in fennel, star anise, vanilla beans and acacia, among others. Mainly used to prepare flavors such as vanilla, spices, apricot, cream, fennel, caramel, cherry, chocolate, walnut, raspberry, strawberry, mint, etc. The effect is very good when combined with essential oils such as tangerine.
English common name: p-Methoxybenzaldehyde (p-Anisaldehyde; Anisic aldehyde)
Category: Naturally equivalent flavors and artificial flavors
Preparation and synthesis methods of anisaldehyde
1. P-cresol methyl ether is obtained by methylation of p-cresol, and then oxidized by adding manganese dioxide and sulfuric acid.
2. Obtained from the oxidation of anisole.
3. Preparation of anisaldehyde by ozonation of anethole
Using anethole as raw material and a mixture of acetic acid and cyclohexane as solvent, anisaldehyde is prepared by ozonation method. The effects of solvent, ozonation time, reducing agent dosage, reduction decomposition time and reduction temperature on the reaction results were investigated, and the ozonation reaction series was preliminarily discussed. The optimized process conditions are: Eu (acetic acid): Eu (cyclohexane) = 1:4, ozonation time is 100 min, n (NaHSOs)/bamboo (anethole) = 1.1, reduction decomposition time 60 min, reduction temperature 80℃. Under these conditions, the product yield is ≥84% and the purity is ≥98%.
Institution: School of Chemical Engineering, Qingdao University of Science and Technology
Name: Journal of Qingdao University of Science and Technology, 2007(2): 117-120
4. Preparation of anisaldehyde from star anise oil
North Star Anise It is called aniseed, and in the south it is called ergot; as traditional Chinese medicine, it is called anise and star anise. It has a strong hawthorn flower aroma, sweet taste and warm nature. Anise is a precious economic tree species unique to my country's southern subtropics. Forest products star anise fruit and star anise oil (fennel oil) are excellent seasonings, cosmetics, spices and medicinal raw materials. An important organic intermediate - anisaldehyde (also known as p-methoxybenzaldehyde) can be obtained through oxidation of star anise oil. Because of its long-lasting hawthorn aroma and attractive fragrance, it is widely used in the preparation of sweet floral and clove scents. and hawthorn flavor, etc., used in the preparation of flavors for food, sugar and beverages; in terms of organic intermediates, it is an intermediate for the preparation of pharmaceutical porphyrin photosensitizers, hydroxycarbyl penicillins, etc.; in agriculture It can be used as a pesticide, biological growth inhibitor, etc. Considering that Guangxi and other places in my country are rich in star anise raw materials, and anisaldehyde has good market prospects and high economic value, some research has been conducted on the preparation of anisaldehyde using anise oil as raw material. In view of the shortcomings of the traditional preparation method of anisaldehyde, such as complex pretreatment, serious equipment corrosion, large pollution, and low yield, this article conducted a systematic study in the following two aspects:
[1] Anise oil For the process of preparing anisaldehyde from ozone oxidation-reduction of raw materials, the optimized process operating conditions were obtained through orthogonal experiments based on single-factor experiments. Compared with the existing process of extracting anethole from anise oil and then oxidizing anethole to prepare anisaldehyde, the research results show that the reaction steps are short and the operation is simple.
[2] The UV spectrophotometric method was used to explore the determination process of anisaldehyde content, and the optimal operating parameters of the determination process were obtained. Compared with the existing gas chromatography method for detecting anisaldehyde content, the biggest advantage of this method is that the method is simple, easy to operate, has low requirements for equipment, is accurate and fast, and has good promotion prospects and reference value.
The results of this study are as follows:
[1] The conditions of the ozonation link were optimized, and the optimized process conditions were: the ratio of the two solvents in the composite solvent is 1:3, and the ratio of solvent to raw materials is 5 :1, the reaction temperature is 15℃, the reaction time is 25min. The yield of the reaction at this time was 79.3%.
[2] The best reaction conditions for detecting anisaldehyde content by UV spectrophotometry: Dilute 1mL of the sample to a certain proportion into a 10mL stoppered colorimetric tube, add 2mL of 6mol/L hydrochloric acid, and then add 0.08mol /L thiobarbituric acid solution 2mL, dilute to the mark with distilled water, shake well, leave it for a period of time, use a 1cm cuvette and use the blank sample as a reference to measure the absorbance value. Substituting into the standard curve, the content of anisaldehyde can be obtained. The main features of this project are: for the first time, ultraviolet spectrophotometry is used to detect the content of anisaldehyde; for the first time, the process technology of directly oxidizing anisaldehyde using anise oil as raw material is obtained. This project was commissioned and developed by Fudan University. The research results have certain theoretical value and practical application value for the deep processing of star anise in Guangxi.
Uses of anisaldehyde
Anisaldehyde has a long-lasting hawthorn aroma. It is used as the main spice in hawthorn, sunflower and lilac essences; as the fragrance in lily of the valley essence; as the modifier in osmanthus essence, and can also be used in daily flavors and food flavors. This product is an edible spice that is temporarily allowed for use in my country's GB2760-86. It is mainly used to prepare flavors such as vanilla, spices, apricots, cream, fennel, caramel, cherries, chocolate, walnuts, raspberries, strawberries, mint, etc.Refined. The effect is very good when combined with essential oils such as tangerine. As an excellent brightener for cyanide-free zinc plating DE additives, it can improve anodic polarization within a wide current range, obtain bright coatings, and create favorable conditions for environmental protection. It is used in the pharmaceutical industry to manufacture antimicrobial drugs such as amoxicillin and is an intermediate of antihistamine drugs.
Toxicological properties: 1. ADI1mg/kg (CE). 2. LD501510mg/kg (rat, oral). 3. Rats were fed with feed containing 1,000 mg/kg anisaldehyde for 27 to 28 weeks, or fed with 10,000 mg/kg for 15 weeks. No abnormalities were found in growth, blood, or tissue.
Storage: Store in a cool and dry place, do not stack in the open.
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