Name | Vanillin |
Synonyms | Vanilin Vanillin Vanilline Vanillin NAT Vanillaldehyde Vanillin Powder Vanillin natural 2-Methoxy-4-formylphenol 4-Formyl-2-methoxyphenol Protocatechualdehyde, methyl- 3-Methoxy-4-hydroxybenzaldehyde 4-Hydroxy-3-methoxybenzaldehyde 4-Hydroxy-3-methoxy-benzaldehyde 3-Methoxy-4-hydroxybenzaldehyde (vanillin) |
CAS | 121-33-5 |
EINECS | 204-465-2 |
InChI | InChI:1S/C8H8O3/c1-11-8-4-6(5-9)2-3-7(8)10/h2-5,10H,1H3 |
Molecular Formula | C8H8O3 |
Molar Mass | 152.15 |
Density | 1.06 |
Melting Point | 81-83°C(lit.) |
Boling Point | 170°C15mm Hg(lit.) |
Flash Point | 147 °C |
JECFA Number | 889 |
Water Solubility | 10 g/L (25 ºC) |
Solubility | Soluble in 125 times water, 20 times ethylene glycol and 2 times 95% ethanol, soluble in chloroform. |
Vapor Presure | >0.01 mm Hg ( 25 °C) |
Vapor Density | 5.3 (vs air) |
Appearance | White needle crystal. |
Color | White to pale yellow |
Merck | 14,9932 |
BRN | 472792 |
pKa | pKa 7.396±0.004(H2OI = 0.00t = 25.0±1.0) (Reliable) |
PH | 4.3 (10g/l, H2O, 20℃) |
Storage Condition | 2-8°C |
Stability | Stable. May discolour on exposure to light. Moisture-sensitive. Incompatible with strong oxidizing agents, perchloric acid. |
Sensitive | Air & Light Sensitive |
Refractive Index | 1.4850 (estimate) |
MDL | MFCD00006942 |
Physical and Chemical Properties | White needle-like crystals. Aromatic odor. |
Use | As a standard reagent for organic analysis |
Hazard Symbols | Xi - Irritant |
Risk Codes | R22 - Harmful if swallowed R36/37/38 - Irritating to eyes, respiratory system and skin. R36 - Irritating to the eyes |
Safety Description | 26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
WGK Germany | 1 |
RTECS | YW5775000 |
TSCA | Yes |
HS Code | 29124100 |
Toxicity | LD50 orally in rats, guinea pigs: 1580, 1400 mg/kg (Jenner) |
Raw Materials | xylidine mixture of isomers Sulfuric acid Methenamine Hydrochloric acid Guaiacol |
Downstream Products | 3,4-Dimethoxybenzaldehyde o-Vanillin 3-Hydroxy-4-methoxybenzaldehyde |
Reference Show more | 1. Tang Xiaoye Zhuang Xin Yu Wei et al. Pumpkin phenolic substances and antioxidant activity are affected by cooking methods [J]. Food Science and Technology 2016 041(005):223-228. 2. Zhang Li, Liu Wenjing, Liu Tengfei, et al. Based on Principal Component Analysis, Quality Evaluation Model of Dongting Biluochun [J]. Food Research and Development, 2018. 3. Yu Qun, Duan Weiwen, liu Bing, et al. Optimization of Ultrasonic-assisted Extraction Process of Active Substances from Worry Dun Grass [J]. Food Research and Development, 2016, 37(013):52-55. 4. Pei Zhisheng, Xue Changfeng, Wen Pan, et al. Research on Worry Dun Grass Okra Compound Functional Beverage [J]. Food Industry, 2018, v.39;No.260(05):99-102. 5. Zhu Chaoyang, Hu Renhuo, Kong Qiong, et al. Study on bactericidal effect of crude extract of Sapindus mukorossi [J]. Anhui Agricultural Sciences, 2014, 000(034):12081-12082. 6. Zhang Qiao, Gu Xinzhe, Wu Yongjin, Tu Kang. Changes of Functional Components and Analysis of Volatile Components in Loquat Peel before and after Hot Air Drying [J]. Food Science, 2016,37(16):117-122. 7. Li Dehai, Zhu Xiaoran, Wang Lu, et al. Study on Vacuum Coupled Ultrasonic Extraction of Lignin and Its Antioxidant and Antimicrobial Activities [J]. Food Industry Science and Technology, 2019(22). 8. Meiying, Shao Ling, Lin Peihua, etc. Effects of Planting Patterns on Growth of Morinda officinalis [J]. Journal of Tropical and Subtropical Plants, 2020(2):163-170. 9. Shao Ling, Li Meiying, Li Xuerong, et al. Studies on Botanical Characters and Pharmacodynamic Components of Two Planting Patterns of Morinda officinalis in Zhaoqing [J]. Chinese Medicinal Materials, Volume 42, Issue 11, 2019, pp. 2480-2485, MEDLINE ISTIC PKU, 2020. 10. Zhao Xianming. Study on Determination Method of Sulfuric Acid-Vanillin for Total Catechins in Tea [J]. Anhui Agricultural Sciences, 2010, 038(018):9766-9770. 11. He Zhigui, Nie Xiangzhen, Hui Xiaohan, et al. Study on Extraction of Anthocyanin from Three Leaves by Ultrasonic Assisted Method [J]. Journal of Northwest Forestry University, 2019, 34(3):207-211. 12. Yang Yang, Zhang Binwu, Lan Dengming, Si Jianhua, Xie Fei, Gui Xiang, Liu Junliang. Analysis of proanthocyanidins in Lycium ruthenicum fruits [J]. Chinese Agronomy Bulletin, 2019,35(22):142-146. 13. Li Tianye, Liu Weihua [1,2], Liang Na, et al. Evaluation of gingerol and its antioxidant activity in ginger and its different processed products [J]. Food Industry, 2016(12):180-183. 14. Li Dehai, Zhu Xiaoran, Wang Lu, etc. salting-out assisted enzyme extraction of Aralia elata saponin and its antioxidant activity [J]. modern food science and technology, 2018, v.34;No.232(12):31 135-142. 15. Liu Yu, Tang Bin, Li Song. Trametes sp. Optimization of decolorization conditions for acid chrome blue K catalyzed by LS-10C laccase [J]. Journal of Anhui University of Engineering 2016 31(004):12-16. 16. Shan Wang, Chen Yongsheng, liang Xiaowei, et al. Synthesis of Hydroxycinnamic Acid Derivatives and Their Antioxidant Structure-Activity Relationship [J]. Food Industry Science and Technology, 2017(12):293-297 338. 17. Zhang Yipei, Zhang Ting, Shi Yiheng, et al. Processing Technology of Quinoa Tea and Analysis of Phenolic Composition [J]. Food Science, 2019, 040(012):267-274. 18. Liu, Y., cai, C., Yao, Y. and Xu, B. (2019), Alteration of phenolic profiles and antioxidant capacities of common buckwheat and tartary buckwheat produced in China upon thermal processing. J. Sci. Food Agric., 99: 5565-5576. https://doi.org/10.1002/jsfa.98 19. Tian, Ya-qin, et al. "Comparison of different extraction techniques and optimization of the microwave-assisted extraction of saponins from Aralia elata (Miq.) Seem fruits and rachises." Chemical Papers 74.9 (2020): 3077-3087.https://doi.org/10.1007/s11696- 20. [IF = 10.618] Yan Zhang et al. "Bimetallic molecularly imprinted nanozyme: dual-mode detection platform." Biosens Bioelectron. 2022 Jan;196:113718 21. [IF = 7.514] Wenyang Tao et al. "Extraction and identification of proanthocyanidins from the leaves of persimmon and loquat." Food Chem. 2022 Mar;372:130780 22. [IF = 7.514] Ziyun Xu et al. "Effects of UV-C treatment and ultrafine-grinding on the biotransformation of ergosterol to vitamin D2, physiochemical properties, and antioxidant properties of shiitake and Jew's ear." Food Chem. 2020 Mar;309:125738 23. [IF = 7.514] Xiaoming Yu et al. "Impact of processing technologies on isoflavones, phenolic acids, and antioxidant capacities of soymilk prepared from 15 soybean varieties." Food Chem. 2021 May;345:128612 24. [IF = 4.556] Fangfang Tie et al. "Proanthocyanidins Ameliorated Deficits of Lipid Metabolism in Type 2 Diabetes Mellitus Via Inhibiting Adipogenesis and Improving Mitochondrial Function." Int J Mol Sci. 2020 Jan;21(6):2029 25. [IF = 4.35] Qian Ge et al. "Effects of Simultaneous Co-Fermentation of Five Indigenous Non-Saccharomyces Strains with S. cerevisiae on Vidal Icewine Aroma Quality." Foods. 2021 Jul;10(7):1452 26. [IF = 3.935] Jingyun Zheng et al. "A systematic investigation on free phenolic acids and flavonoids profiles of commonly consumed edible flowers in China." J Pharmaceut Biomed. 2019 Aug;172:268 27. [IF = 3.935] Yong-Sheng Wu et al."Chemical profiling of Callicarpa nudiflora and its effective compounds identification by compound-target network analysis."J Pharmaceut Biomed. 2020 Apr;182:113110 28. [IF=3.638] Yongxiang Liu et al."Alteration of phenolic profiles and antioxidant capacities of common buckwheat and tartary buckwheat produced in China upon thermal processing."J Sci Food Agr. 2019 Sep;99(12):5565-5576 29. [IF=3.512] Yahong Chen et al."Identification of Potential Human Ryanodine Receptor 1 Agonists and Molecular Mechanisms of Natural Small-Molecule Phenols as Anxiolytics."Acs Omega. 2021;XXXX(XXX):XXX-XXX 30. [IF=3.205] Jie Tang et al."Metabolite profiling of Shuganzhi tablets in rats and pharmacokinetics study of four bioactive compounds with liquid chromatography combined with electrospray ionization tandem mass spectrometry."J Chromatogr B. 2021 Aug;1179:122827 31. [IF=3] Qu Lala et al."Phenotypic assessment and ligand screening of ETA/ETB receptors with label-free dynamic mass redistribution assay."N-S Arch Pharmacol. 2020 Jun;393(6):937-950 32. [IF=2.72] Wenwen Zhang et al."Optimized extraction based on the terpenoids of Heterotrigona itama propolis and their antioxidative and anti-inflammatory activities."J Food Biochem. 2020 Aug;44(8):e13296 33. [IF=2.431] Hu Xiang et al."Optimization of extraction process and antioxidant activities of saponins from Camellia fascicularis leaves."J Food Meas Charact. 2021 Apr;15(2):1889-1898 |
white to yellowish needle-like crystals or crystalline powder, with a unique aroma of vanilla beans. Soluble in ethanol, acetic acid, ether, chloroform and hot volatile oil, soluble in hot water and cold vegetable oil, micro cold water. In the air is easy to be oxidized to vanillin acid, in alkaline solution is easy to change color.
vanillin was prepared from p-hydroxybenzaldehyde by Bromination and methoxylation.
with vanilla bean aroma and strong milk aroma, widely used in food, chocolate, ice cream, beverage and daily cosmetics in the role of flavoring and fixing. Generally, it is 970mg/kg in chocolate; 270mg/kg in chewing gum; 220mg/kg in cakes and biscuits; 200mg/kg in candy; 150mg/kg in condiment; And 95mg/kg in cold drink.
FEMA | 3107 | VANILLIN |
LogP | 1.17 at 25℃ |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Overview | vanillin is the first human flavor, synthesized successfully in 1874 by Dr. M. Halman and Dr. G. They are generally divided into methyl vanillin and ethyl vanillin. (1) methyl vanillin: white or yellowish crystal, with vanilla aroma and strong milk aroma, is the largest variety in the perfume industry, it is the main ingredient of the cream vanilla flavor, which is popular among people. Its use is very extensive, such as in the food, daily chemical, tobacco industry as a flavor raw material, flavoring agent or fixative, including beverages, candy, cakes, biscuits, bread and fried goods and other food consumption. Vanillin has not been reported to be harmful to humans. (2) ethyl vanillin: white to yellowish needle-like crystal or crystalline powder, similar to vanilla bean aroma, aroma is more concentrated than methyl vanillin. It is one of the most important synthetic spices in the world. It is an indispensable raw material in the food additive industry, and its aroma is 3-4 times that of vanillin, with a strong vanilla bean aroma, and long-lasting fragrance. It is widely used in food, chocolate, ice cream, beverage and cosmetics for daily use. In addition, ethyl vanillin can also be used as a feed additive, a brightener in the electroplating industry, and an intermediate in the pharmaceutical industry. |
important spices | vanillin commonly known as vanillin powder, vanillin, Yunna powder, vanilline, vanillin, an important spice extracted from vanilla beans of the Rutaceae family is one of the most productive varieties of synthetic spices, and is an important raw material for the preparation of chocolate, ice cream, chewing gum, cakes and tobacco flavor. Naturally occurring in vanilla pods, as well as in clove oil, oak moss oil, Peru balsam, turbaler and benzoin. vanillin has a strong and unique vanilla bean aroma, stable aroma, not volatile at higher temperatures. Susceptible to the impact of light, gradually oxidized in the air, when alkali or alkaline material easy to change color. The aqueous solution reacts with ferric chloride to form a blue-purple solution. It can be used in many daily flavor formulations, but is mainly used in food flavors. In particular, it is widely used in candy, chocolate, beverage, ice cream, alcohol, and is also useful in tobacco flavor. There are no restrictions on IFRA. However, due to easy to cause discoloration, should pay attention to the use of white flavoring products. vanillin is also an important food flavor, as a foundation flavor, used in almost all flavor, a large number of used in the food industry, as a food flavor is widely used in bread, cream, ice cream, the amount is 0.01 to 0.04% in cakes and biscuits, and 0.02 to 0.08% in sweets. It is one of the most used spices in baked goods and can be used in chocolate, biscuits, cakes, pudding and ice cream. Before use with warm water to dissolve, the effect is better. The highest amount of baked food was 220mg/kg, and the chocolate was 970mg/kg. It is widely used in cosmetic essences as a fixative, a coordinating agent and a changing agent. It is also an important flavoring agent for beverages and foods. It is also used in the manufacture of pharmaceutical L-dopa (L-dopa), methyldopa, etc. It can also be used as a nickel, chromium metal plating brightener. |
function and purpose | 1. Edible spices: vanillin is an edible flavoring agent, with vanilla bean aroma and strong milk flavor, which is an indispensable and important raw material in the food additive industry, widely used in a variety of need to increase the flavor of milk flavor in the flavor of food, such as cake, cold drinks, chocolate, candy, biscuits, instant noodles, bread and tobacco, flavor wine, toothpaste, soap, perfume cosmetics, ice cream, Beverages and Cosmetics in daily use in the role of flavoring and fixed flavor. Can also be used for soap, toothpaste, perfume, rubber, plastic, medicine. Meet FCCIV criteria. 2. Domestic vanillin is mainly used in food additives. In recent years, its application in the field of medicine has been expanding and has become the most potential field of vanillin application. At present, domestic consumption of vanillin: Food industry accounted for 55%, pharmaceutical intermediates accounted for 30%, feed flavor Liu accounted for 10%, cosmetics accounted for 5%. Foreign vanillin has a wide range of applications, a large number of used in the production of pharmaceutical intermediates, but also for plant growth promoters, fungicides, lubricating oil defoaming agent, electroplating brightener, printed circuit board production of conductive agents. |
concentrated fumaryl vanillin | concentrated fumaryl vanillin has a strong and lasting aroma of clove and vanilla, the intensity of its aroma is 16 to 25 times that of vanillin. It was successfully developed as early as the 20 s of the 20th century. The initial synthesis route is to use safrole as raw material, which is hot-pressed with potassium hydroxide alcohol solution to make ring opening, and then ethyl sodium sulfate to make ring on the hydroxyl group, finally, in ethanol solution with sulfuric acid hydrolysis to obtain concentrated fumaranillin. However, because the purity of the aroma of the product is not enough, it is rarely used in practice. A synthetic route for the preparation of concentrated fuvanillin from eugenol was developed in the 50's of the 20th century (U.S. Patent No. 2663741), and industrial production was realized. In the 60 s of the 20th century, the perfume chemists of the former Soviet Union successfully developed a synthetic route from the more cheap and easily available catechol. catechol was mono-alkylated with allyl chloride in 75% yield, followed by rearrangement in 35% ~ 38% yield, and mono-ethylated with sodium ethyl sulfate in 82% yield; finally, potassium hydroxide isomerization was used to obtain concentrated vanillin, the yield was 84%, and the melting point of the crude product after recrystallization was 85.5~86. concentrated vanillin can be used in candy, beverage, ice cream and other food flavor formulas, FEMA number 2922. Can also be used in cosmetics and soap and other cosmetic flavor formulations. It can be used not only as a fragrance, but also as a synergist and antioxidant. The former Soviet Union perfumers had different views on the aroma properties of the concentrated fumaranillin. They added it to chocolate and other food flavors and found that the product had no vanillin aroma, so it was not considered to be a substitute for vanillin in food flavors. However, when used in the perfuming test of soap, it was found that the soap with it has a strong clove and vanilla aroma. In addition, it is different from vanillin and isoeugenol, light, oxidation is very stable, The soap sample did not change color after storage. Therefore, it is suggested that the concentrated vanillin should be used in the formula of daily chemical essence, especially in the Phantom essence. |
method for industrial production of vanillin | over 100 years of industrial production of vanillin, many synthetic approaches and methods have been studied, but there are mainly three methods used in large-scale industrial production. A. Lignin route The Lignin Sulfonate contained in the waste liquid of sulfite pulp in the paper industry is used as the raw material, which is prepared by alkaline hydrolysis at high temperature and high pressure, then dehydration and oxidation. This method is mainly used to produce vanillin in Canada and the United States. B. Guaiacol-formaldehyde route guaiacol is the most important raw material for the synthesis of vanillin. The synthetic route of guaiacol, formaldehyde and p-nitrosodimethylaniline is also called nitroso method. The former Soviet Union and China and other countries mainly used the law. C. Guaiacol-glyoxylic acid route using guaiacol and glyoxylic acid as raw materials, vanillin was prepared by condensation, oxidation and decarboxylation. The method was successfully developed by the French company Rhone-Poulenc and produced on a large scale. The glyoxylic acid used can be obtained by ozonolysis of dimethyl Maleate (German patent no. 3224795). The synthetic route is considered as the most suitable method at present because of its convenient source of raw materials, fewer reaction steps, lower cost and less pollution of three wastes. |
assay | method-analysis by UV spectrophotometry (see GT-29). Preparation of standard solution about 100mg of reference standard vanillin for accurate weighing and taking medicine is put into a 250ml volumetric flask, fixed volume with methanol and mixed. Take 2.0ml of the solution, put it into a ml volumetric flask, and mix it with methanol. Preparation of the sample solution about 100mg of the sample was accurately weighed, and the preparation method was the same as the preparation of the standard solution described above. The above solutions were put into a 1cm quartz cell, and the absorbance was measured at a maximum absorption wavelength of about 308nm. Calculate the content (X)(mg) of vanillin (C8H8O3) in the sample As follows: X = 12.5c(Au/As) where c-concentration of vanillin in the standard solution, μg/ml;Au-absorbance of sample solution; As-absorbance of standard solution. Method two according to Gas chromatography (GT-10-4) with non-polar column method. |
toxicity | LD50 Orly in rats, quinea pigs: 1580, 1400 mg/kg (Janner) |
usage limit | FEMA(mg/kg): soft drinks 63; Cold drinks 95; Candy 200; Baked goods 220; pudding 120; Gum 270; Chocolate 970; Decorative layer 150; Margarine 0.20; Syrup 330~20000. According to FAO/WHO: the maximum allowable dosage of canned baby food and cereal food for convenience food is 70 mg/kg(1992). |
Industry Development | China is one of the world's largest export countries of vanillin, with 2350 tons of domestic demand, accounting for 30% of the output in 2002years, the remaining 70% is for export. In, only 273 tons were exported, compared with 1700 tons in 1993and 4653 tons in 2002. From 1993 to 12%, the average annual growth rate of vanillin export in China was, and it has a good reputation in North America, Europe, Southeast Asia and other markets. The global demand for vanillin was about 17500 tons in 2012, among which the demand of developed countries was in equilibrium, while the demand for vanillin in developing countries was significantly increased, so that the total demand for vanillin is still in the growth period. The actual demand in China has reached about 3000 tons, and the current per capita use is still slightly lower than the global per capita use. Jiaxing China Chemical Co., Ltd., a major domestic supplier, is the world's largest professional manufacturer of vanillin, with an annual output of 10000 tons of methyl vanillin and 2000 tons of ethyl vanillin, more than 80% of the products are used for export. There are mainly three vanillin manufacturers in foreign countries, namely, the French Rhodia company, the BOLI company of Norway, and the Japanese Yubu company. Among them, the French Rhodia is the world's most famous vanillin production enterprises, with an annual output of 8000 tons, the device is distributed in France, the United States. at present, domestic and international companies use the guaiacol-glyoxylic acid method to produce vanillin, except for the lignin method used by Bolliger company in Norway. |
purpose | used as food flavor, daily chemical flavor, pharmaceutical intermediate is a good spice to obtain powder flavor and bean flavor. It is often used for foundation and fragrance. Can be widely used in almost all types of fragrance, such as Violet, Grass Blue, sunflower, Oriental flavor. It can be used in combination with foreign Jasmine aldehyde, isoeugenol benzyl ether, coumarin, Musk, etc. It can also be used to cover up bad breath. In the food, tobacco flavor is also widely used, and the amount is also larger. In the vanilla bean type, cream, chocolate, taifei flavor are essential spices. vanillin is a kind of edible flavor permitted by regulations in China, which can be used as a fixative and is the main raw material for the preparation of vanilla essence. Can also be directly used for biscuits, cakes, candy, beverages and other food flavoring. Dosage according to the normal production needs, generally in the chocolate 970mg/kg; Chewing gum 270mg/kg; Cakes, biscuits 220mg/kg; Candy 200mg/kg; condiment in 150mg/kg ~ 95mg/kg in cold drinks. GB 2760 1996 provides for the permitted use of flavorants. Widely used in the preparation of vanilla, chocolate, cream and other flavors, the dosage of up to 25% ~ 30%, or directly for biscuits, cakes, the dosage of 0.1% ~ 0.4%, cold drinks 0.01% ~ 0.3%, Candy 0.2% ~ 0.8%, in particular, they contain dairy products. important synthetic spices, widely used in daily chemicals, used as food, tobacco and alcohol with the method. In the food industry, it is used in the preparation of vanilla, chocolate, cream and other flavors, the dosage can reach 25-30%, directly in the biscuits, cakes, the dosage of 0.1-0.4%, cold drinks 0.01-0.3%, candy 0.2-0.8%, especially containing dairy products. Used in analytical chemistry to examine the proteins azalene, phloroglucinol and tannic acid. In the pharmaceutical industry, for the production of antihypertensive drugs methyldopa, catechin phenolic drug Dopa, as well as stop, such as trichlorfon. used as a standard reagent for organic analysis determination of protein, azainide, phloroglucinol, tannic acid, iron ions, determination of chlorine, flavor and spice from benzoic acid, standard for the determination of methoxy groups by organic microanalysis. It is used for testing protein, azainide, phloroglucinol, tannic acid, iron ion; Chlorine is measured from benzoic acid; It is used as a standard reagent for the determination of methoxy groups by organic microanalysis . |
production method | N,N-dimethylaniline was acidified to salt with hydrochloric acid, and nitrated with sodium nitrite to get p-Nitroso-N,N-dimethylaniline hydrochloride. It was condensed with guaiacol and formaldehyde at 41-43 °c. It was then extracted with benzene. The first distillation, recrystallization with benzene, and a second distillation, recrystallization with water. The product was dried at 50 °c. In sulfite pulp waste, lignosulfonate containing the structural unit of betalol is oxidized under alkaline conditions and then hydrolyzed to obtain vanillin. Raw material consumption (kg/t) guaiacol (98%) 1460 sodium nitrite 640N,N-dimethylaniline (98%) 974 hydrochloric acid (30%) 6000 formaldehyde (99%) 320 obtained from the extraction of vanilla beans. By O-aminoanisole by diazo hydrolysis into guaiacol, in the presence of nitrosodimethylaniline and catalyst, and formaldehyde condensation, or in potassium hydroxide catalyzed reaction with chloroform, and then separated by extraction, vacuum distillation and crystallization purification. It can also be made of wood pulp waste liquid, eugenol, guaiacol, safrole and the like. using lignin as raw material, vanillin can be prepared from lignin contained in the waste liquor of sulfuric acid pulping in a paper mill. Generally, the waste liquid contains 10% ~ 12% of solids, of which 40% ~ 50% is calcium lignosulfonate. First, concentrate the waste liquid to 40% ~ 50% of solids, add 25% NaOH of lignin, heat to 160~175 ℃ (about 1.1~1.2MPa), and oxidize with air for 2H, the conversion rate can generally reach 8 ~ 11% of lignin. The vanillin is extracted from the oxide with benzene, and the benzene is recovered by steam distillation. Sodium bisulfite is added to the oxide to form bisulfite, which is then separated from the impurities and then decomposed with sulfuric acid to obtain the crude vanillin, the final product was obtained by distillation under reduced pressure and recrystallization. Using guaiacol as raw material, trichloro-acetaldehyde method guaiacol and trichloro-acetaldehyde in the presence of soda ash or potassium carbonate, heated to 27 ℃ condensation to produce 3-methoxy-4-hydroxyphenyl trichloromethyl methanol, unreacted guaiacol was removed by steam distillation. In the presence of caustic soda, With nitrobenzene as oxidant, heating to 150 deg C to oxidative decomposition of vanillin; Can also be used as a catalyst, Cu-CuO-CoCl2 at 100 deg C air oxidation, reaction after extraction with benzene vanillin, the final product was purified by distillation under reduced pressure and recrystallization. Glyoxylic acid method in order to add guaiacol, sodium hydroxide solution and sodium carbonate in glyoxylic acid solution, and condensation at 30~33 ℃ to produce 3-methoxy-4-hydroxyphenylhydroxyacetic acid. After the unreacted guaiacol was extracted with a solvent, a sodium hydroxide solution was added, and vanillin was oxidatively cleaved by heating to 100 ° C. In the presence of nitrobenzenesulfonic acid and calcium hydroxide. The oxidation product was neutralized and then extracted with dichloroethane. The crude product was purified by vacuum distillation and recrystallization to obtain the final product. 30% hydrochloric acid and 61.5 water were added to the reaction kettle by the nitroso method, and after cooling to 10 ° C., 25% of dimethylaniline was added dropwise within 2H at a temperature not exceeding, and then stirring was continued for 20min. After cooling to 6 ° C., 25% aqueous solution of 75kg of sodium nitrite was added dropwise, and the temperature was controlled at 7-10 ° C. And stirring was continued for 1 hour. P-nitrosodimethylaniline hydrochloride was filtered off, and a certain amount of ethanol and concentrated hydrochloric acid were added to dilute the solid to give P-nitrosodimethylaniline. Condensation of guaiacol with P-nitrosodimethylaniline: 26kg of urotropine was dissolved in 34kg of water, and then a mixture of 126kg of guaiacol and 63kg of ethanol was added and stored in a high position tank for use. 550kg of the mixture of p-nitrosodimethylaniline hydrochloride and ethanol obtained above was added into a reaction kettle, and the metal salt catalyst was added after heating to 28 ° C, then, when heated to 35-36 °c, The guaiacol mixture (3-3.5h) was added dropwise, the temperature was maintained at 40-43 °c, and the reaction was continued for 1h after the dropwise addition. Then, 100kg of water at 40 ° C. Is added to dilute and stir for 15min, and the content of vanillin in the condensation solution should be above 11%. The above-mentioned condensation liquid was continuously countercurrent extracted in a rotary tray liquid-liquid extraction column using benzene as a solvent. The benzene extract contains a large amount of hydrochloric acid, which is washed with water and then neutralized with alkali to Ph = 4; The benzene is recovered by distillation with an ascending film evaporator, and then distilled with steam for 1H to remove residual benzene; the water was distilled off under reduced pressure, and finally the crude vanillin was rapidly distilled off at 120-150 °c (666.6), with a freezing point of about 70 °c. The crude product was dissolved in toluene at 70 °c, filtered and cooled to 18-20 °c, suction filtered and washed with a small amount of toluene to obtain vanillin. Then a second vacuum distillation was carried out to collect 130 ~ The 140 °c (266.6-399.9) fraction was dissolved in dilute ethanol at 60-70 °c and slowly cooled to 16-18 °c for crystallization (1H). Filter with a centrifuge and wash with a little dilute ethanol. Finally, at 50~60 deg C, hot air drying 12h to get the finished product. According to guaiacol, the yield can reach more than 65%. P-hydroxybenzaldehyde method vanillin was prepared from p-hydroxybenzaldehyde by mono-Bromination and methoxylation. In a 0.131 mL flask, 16g (6.8 mo1) of p-hydroxybenzaldehyde and 90mL of solvent were added, and then 0.131 mL (mo1) of liquid bromine was dissolved and heated to 40-45 ° C. For 6 hours. The solvent is extracted under reduced pressure, the residue is boiled with water, filtered while hot, the filtrate is cooled to crystallize, filtered and dried to obtain white crystalline 3-bromo-4-hydroxy-benzaldehyde, melting point 123~124 ℃, the yield was 90%. 12g(0.0597 mol) of the above product, 45ml (0.230 mol) of a 28.24% solution of sodium methoxide, 35ml of DMF and 0.2g of CuCl were added to a 115 ml flask and reacted for 1.5h at °c. Then the solvent was extracted, the residue was acidified with 18% hydrochloric acid to Ph = 4~5, and then extracted with hot benzene for 3 times, the aqueous layer was removed, and the benzene layer was distilled off under reduced pressure to obtain a brown liquid. It was dissolved in hot dilute alcohol solution, cooled to precipitate white crystals, filtered and dried to obtain product vanillin 8.3g, melting point 81~82 ℃, purity 99.5%, yield 91.1%. |
spontaneous combustion temperature | >400°C |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |