The procedure of Example 6 was repeated except 0.102 mol of hydrochloric acid was used in place of 0.053 mol of sulfuric acid in acidification. The resulting cinnamic acid is then precipitated by addition of a mineral acid. Preparation of calibration solution Stock solutions (500 µg/ml) of cinnamic acid and harpagoside were prepared by dissolving cinnamic acid and harpagoside into methanol. 0000001089 00000 n It was then dissolved in a small amount of DMF and added into ice water with stirring. Publication: 2006-04-26. Determination of mangiferin, jateorrhizine, palmatine, berberine, cinnamic acid, and cinnamaldehyde in the traditional Chinese medicinal preparation Zi-Shen pill by high-performance liquid chromatography. Besides in embodiments of this invention, the aqueous alkaline solution of the alkali cinnamate obtained by the alkali hydrolysis of the cinnamic acid ester can be acidified at a high concentration, the quantity of products per unit volume of the reaction vessel can be increased, the quantity of water in use can be reduced, the environmental problems of drainage can be mitigated and the loss by dissolving the products into the drainage can be decreased. In the method of this invention, alcohols generated in the course of the hydrolysis reaction may optionally be recovered, for example, by distilling from the system during or after the reaction. 2004 Apr;42(4):207-10. I have already done a Doebner reaction using using benzaldehyde and malonic acid. 1b), cinnamyl alcohol (Fig. © 2004-2021 FreePatentsOnline.com. Hence the cinnamic acid having good quality can be obtained efficiently and in good yield. trans -Cinnamic acid (TCD, also known as trans --pheny-lacrylic acid) is one of the main chemical constituents of cinnamon which belongs to plant Lauraceae [, ]. Cinnamic acid was separated using water containing 0.005% (v/v) formic acid and acetonitrile as a mobile phase by gradient elution at a flow rate 0.2 mL/min, equipped with a HALO-C18 column (2.1 × 100 mm, 2.7 μm). The solvent system composed of n-propanol and am­ monia (70: 30) was employed to separate cinnamic acid and benzoic acid from p-hydroxybenzoic acid. 0 The procedure of Example 6 was repeated except 17.6 grams (0.1 mol) of ethyl cinnamate was used in place of methyl cinnamate. Concerning the hydrolysis of cinnamate esters a method has recently been proposed which applies an acid as the catalyst (as described in Japanese Patent Laid-Open No. And the materials may be fed continuously or intermittently at a certain rate. 1a) and its simple derivatives are widely represented in plants. All rights reserved. The term continuous operation mentioned herein is different from what is called batchwise operation in which raw materials are charged in a lump and discharged after ending the reaction. Cinnamic acid thus obtained was 90.0 grams (98.5% yield) and had purity of above 99.9% according to the analysis of liquid chromatography. Cinnamic acid as an unsaturated carboxylic acid might prevent inflammation and periodontal destruction. Besides a step of acidifying the resultant alkaline solution with mineral acids after alkali hydrolysis is required in order to finally obtain the cinnamic acids. Cinnamic acid thus obtained was 14.6 grams (98.5% yield) and had purity of more than 99.9% according to analysis. Patent: Unexamined APPLIC. A 3 &litre flask equipped with a stirrer was charged with 100.0 grams (0.617 mol) of methyl cinnamate and 1260 grams of aqueous solution containing 25.9 grams (0.647 mol) of sodium hydroxide and vigorously stirred for 15 minutes at 80°C. The temperature in the acidification reaction is suitably 10 to 80°C. It is found in Cinnamomum cassia. Besides a method has also been proposed recently wherein styrene or its derivatives are reacted with carbon monoxide, alcohol and oxygen in the presence of a catalyst (as described in Japanese Patent Publication Nos. 31 22 A process of preparing a cinnamic acid by hydrolyzing a cinnamate ester represented by the following formula: Click for automatic bibliography For example, quantity of the raw materials can be set so as to obtain the pH value of not more than 4 after the reaction. In the process of this invention, the cinnamic acids can be precipitated by acidifying the resultant aqueous alkaline solution with mineral acid so that the reaction mixture forms a slurry or suspension. After heating for 15 minutes with stirring, the flask was fitted with a Liebig's condenser and further heated to give 30 grams of distillate. 1. Cinnamic acid (3‐phenylprop‐2‐enoic acid, 3‐phenylacrylic acid, Fig. Herein, we report a simple, dependable, and scalable preparation method for CBDA-4 (Scheme 1). The procedure of Example 6 was repeated except 6.9 grams of 85 wt.% potassium hydroxide in place of sodium hydroxide. The electroreduction of Ar-substituted methyl cinnamates in acetonitrile gave all-trans cyclized hydrodimers stereoselectively (58∼90% de). The yield was low though. 133°C. The main advantage of the method we present is the METHOD: The ability of catching oxygen of the products and raw material were determined through two methods, Marklund method and trace pyrogallic acid method, with autoxidation reaction of … It is a member of styrenes and a member of cinnamic acids. Preferably the whole binary-phase system is substantially free of organic solvents. Synthesis (~r isopropyl 4-methoxy cinnamate by es­ t >rijlcation reaction Calculated quantity of 4-methoxy cinnamic acid, 0000017832 00000 n 102614/'74). 0000004081 00000 n 4-M..: thoxy cinnamic acid was filtered and washed with water until free of acid and then it was dried in an oven (Table 2). Coumarin and trans-cinnamic acid were purchased from Sigma-Aldrich. This UPLC-DAD method was developed and validated for simultaneous quantitation of coumarin, trans-cinnamic acid, trans-cinnamaldehyde, and eugenol. Experiment 5: Preparation of Trans-cinnamic Acid from Malonic acid and Benzaldehyde with the Knoevenagel reaction. Triethylamine and phos-phoric acid were analytical grade, and methanol and acetonitrile were chromatographic grade. A high-performance liquid chromatographic method for the determination and pharmacokinetic study of cinnamic acid in the plasma of rats after having We use cookies to enhance your experience on our website.By continuing to use our website, you are agreeing to our use of cookies. The yield was 88.8% of the theoretical. Therefore, for the technically effective application of the method of this invention, it is desirable to use water in such quantity that the concentration of the alkali cinnamate is l to 20% by weight in the aqueous solution. 3 The resulting solution is chilled, cinnamic acid gets separated as colourless crystals, filtered in the Buchner funnel, washed with a little cold water, drained well and dried at 100 °C. very low. So this is the main drawback of The solution was distilled at about 100°C, a fraction of 98 to 99°C was collected, and 17.8 grams of methanol were recovered as an aqueous solution. It is desirable to provide an industrial method of preparing a cinnamic acid by the hydrolysis of a cinnamate ester with an alkali. This novel approach allows the preparation of various cinnamic acids in good to high yields (up to 81%). 8.6 [140]. The operation may be intermittent with a suitable interval so long as the operation does not make this invention invalid. All the stock solutions were stored in a refrigerator at 4°C. & Terms of Use. The precipitates were filtered with suction, washed with 50 ml of water by stirring in a beaker, filtered again and dried under reduced pressure. Sodium hydroxide or potassium hydroxide is preferably employed among these compounds. : 133 oC) was first melted and heated in an oven at 180 oC for 30 minutes. Its biosynthesis involves the action of the enzyme phenylalanine ammonia-lyase (PAL) on phenylalanine. Ref. A separable flask equipped with a stirrer was charged with 16.2 grams (0.10 mol) of methyl cinnamate, and a solution of 4.3 grams of 97 wt.% sodium hydroxide in 200 grams of water, and the mixture was reacted at 80°C for 15 minutes with vigorous stirring. A silicone type cinnamic acid derivative which is a siloxane having at least one unit represented by the formula (I): ##STR1## and having the other units which may exist in the siloxane being represented by the formula: O.sub. It is preferably in the range of 2 to 15% by weight. Various synthetic methods have been used for the preparation of cinnamic acid and its Cinnamic acid was prepared by oxidation of benzalacetone which was synthesized by condensing benzaldehyde and acetone. 0000010308 00000 n The benzalacetone was further oxidized with sodium hypochlorite to give 88.2% of cinnamic acid, m.p. The procedure of Example l was repeated except 2100 grams of water in the hydrolysis and 200 grams of aqueous sulfuric acid solution containing 0.08 mol of sulfuric acid were used in acidification. These compounds are hydroxy derivatives of cinnamic acid.. generation. Furthermore, the solvents used for the extraction should be recovered in the industrial application. Cinnamic acid is a central intermediate in the biosynthesis of a myriad of natural products including lignols (precursors to lignin and lignocellulose), flavonoids, isoflavonoids, coumarins, aurones, stilbenes, catechin, and phenylpropanoids. 1c), 4‐hydroxycinnamic acid (p‐coumaric acid, Fig. For instance, these processes are methods of preparing cinnamic acid and its derivatives from benzaldehydes as a main raw material by Perkin reaction, Knoevenagel reaction or Claisen condensation (as described in, for example, Organic Reactions, vol. It was validated to be specific, precise, and accurate for the detection and quantitative assessment of these four constituents in encapsulated cinnamon flavoring powder. The purity of the standards was checked before use. Determination of cinnamaldehyde, cinnamic acid, paeoniflorin, glycyrrhizin and [6]-gingerol in the traditional Chinese medicinal preparation Kuei-chih-tang by cyclodextrin-modified micellar electrokinetic chromatography Hsi-Ya Huang, Kuang-Lung Kuo, You-Zung Hsieh* The separation step of the cinnamic acid from the suspension may be carried out batchwise or continuously. CGWW, pp 703 Background: Those reactions that are called aldols derive their name from the early nineteenth-century organic literature. Curve calibration pre-pared from standar solution of trans-cinnamic acid containing 0.5-2.5 µg/mL. by employing a dilute aqueous alkali cinnamate solution, using a dilute aqueous solution of the acid or diluting the system with a special addition of water. It can also inhibit melanoma and proliferation and promote di erentiation of cancer cell in by the' Stuart-method ' of heating o-chlorobenzaldehyde with malonic acid and glacial acetic acid. As a result a homogeneous solution cannot be formed and in the extreme cases the operation is substantially inhibited as a result of solidification. The cinnamate esters include, for example, methyl cinnamate, ethyl cinnamate, propyl cinnamate, butyl cinnamate, ethyl α-methyl-β-phenylacrylate, methyl α-propyl-β-chlorophenylacrylate, methyl β-3,4-dimethoxyphenylacrylate, methyl β-4-methoxyphenylacrylate and benzyl cinnamate. The cinnamic acids can be separated from the mixture by suitable means, for example, filtration, and decantation. UNIV ZHEJIANG. Cinnamate esters are always formed as an intermediate in such processes as Claisen condensation which used benzaldehyde and acetate esters, a method of using benzene or its derivatives and acrylate esters as the raw materials, and a method of employing styrene or its derivatives, carbon monoxide, alcohol and oxygen as the raw materials. The present invention relates to a preparation process of cinnamic acids by the hydrolysis of an alkyl ester of the cinnamic acids. The procedure of Example l was repeated except 0.112 mol of hydrochloric acid was used in place of 0.056 mol of sulfuric acid in acidification. So this is the main drawback of Cinnamic acid is a monocarboxylic acid that consists of acrylic acid bearing a phenyl substituent at the 3-position. Then the aqueous solution of sodium cinnamate and 25 wt.% aqueous sulfuric acid solution were added dropwise at a rate of 13 grams per minute and 2.0 grams per minute respectively. The suspension of the cinnamic acid formed by the acidification of this invention is continuously discharged, and optionally, it may be discharged intermittently. In this study, trans-cinnamic acid (CA) was used as a representative substance of goreisan constituents, and assayed by HPLC-UV. The formed suspension had pH of approximately 1.5 after cooling to room temperature. The quantity of alkali in use is at least one equivalent to the cinnamate ester. Hydroxycinnamic acids (hydroxycinnamates) are a class of aromatic acids or phenylpropanoids having a C 6 –C 3 skeleton. … The reaction pressure is normally atmospheric and yet in some cases slightly decreased or increased pressure is effective. 0000018252 00000 n Cinnamic acid preparation method (PAT - CN1762962) LI HAORAN WENG. It can also be prepared through: mixing the benzoylacetone, sodium carbonate and bleach, generating sodium cinnamic acid, followed by processing with sulfate. Perkin's method was first applied to m-bromobenz-aldehyde by Miller and Rohde (1890) who, after heating the Perkin mixture at 140-50° for as many as twenty hours, obtained a 73% yield of m-bromo-cinnamic acid. Consequently, cinnamic acid obtained was 14.5 grams (97.9% yield) and had purity of above 99.9%. The resultant suspension was cooled to room temperature and filtered with suction. In the acidification of this invention, the batchwise or semi-batchwise operation wherein the aqueous solution of alkali cinnamate is added into the mineral acid, or the continuous operation wherein the reaction is conducted by maintaining the pH value of the system at not more than 4, has the advantage of performing the acidification in the higher concentration of the produced cinnamic acid in the suspension. Carefully, the filtrate is rendered to acidic pH by adding concentrated HCl gradually in small lots at intervals, and with continuous shaking until the evolution of CO 2 ceases completely. These materials form much less intense photochemically generated adduct peaks in the protein quasimolecular ion signal and the adduct peaks that are present are easier to resolve. A series of cinnamic acid esters and their derivatives were synthesized and evaluated for antifungal activities in vitro against four plant pathogenic fungi by using the mycelium growth rate method. The absorbance was measured at … There are cis and a trans isomer exist naturally in a number … 0000001824 00000 n The cell pellet was washed twice with 25 mM potassium phosphate buffer of pH 7.0 and resuspended in the same buffer. Therefore hydrolysis of cinnamate esters is necessary for preparing free cinnamic acids. Consequently, cinnamic acid obtained was 14.4 grams (97.2% yield) and had purity of above 99.9%. 0000002878 00000 n Herein, we report a simple, dependable, and scalable preparation method for CBDA-4 (Scheme 1). Consequently cinnamic acid thus obtained was 14.5 grams (97.9%) and had purity of above 99.9%. 0000000736 00000 n When n is not less than 2, each R1 is the same or different. Water soluble mineral acid which is usually available in industry can be used in the acidification of the alkali cinnamate solution. Consequently, cinnamic acid obtained was 14.5 grams (97.9% yield) and had purity of above 99.9%. Therefore it becomes difficult to conduct the acidification of aqueous solution of the alkali cinnamate with the mineral acid in a high concentration and the amount of products produced per unit volume of the reaction vessel is reduced. As a concrete method, for example, from a flooding port equipped on the reaction vessel, the suspension may be discharged by an overflow mode, or may also be discharged by use of a pump. Cinnamic acid, benzoic acid and p-hydroxybenzoic acid were determined spectrophoto­ metrically after separation on paper chromatogram. Cinnamic acid was prepared by oxidation of benzalacetone which was synthesized by condensing benzaldehyde and acetone. Also , what can be done to convert cinnamic acid to phenyl propionic acid? 31 0 obj<> endobj The procedure of Example 10 was repeated except the dropwise addition rate of aqueous sulfuric acid solution was reduced and pH of the reaction mixture was kept at 5 in acidification. conditions, through a new direct synthesis. Besides the acidification reaction of this invention is also preferably conducted by the continuous operation. In the extreme cases the stirring is inhibited. In the operation of adding the mineral acid into the aqueous solution of alkali cinnamate, however, the reaction mixture often forms a slurried liquid having a high viscosity. The hydrolysis, however, is generally performed by use of alkali such as sodium hydroxide in a homogeneous system which contains aqueous mixture of alcohol, dioxane or acetone (as described in Japanese Patent Laid-Open No. It is also desirable to provide a method of preparing a cinnamic acid by starting the hydrolysis of the cinnamate ester with the alkali in the heterogeneous binary-phase liquid system, followed by acidifying the resultant alkaline solution with the mineral acid through an improved method. hydroxybenzoic acid. Abstract. tional method; mangiferin, jateorrhizine, palmatine, berberine, cinnamic acid, and cinnamaldehyde were all ordered from the National Institute for the Control of Pharmaceutical and Biological Products (Beijing, China). Privacy Policy In the process of this invention, the acidification of aqueous alkaline solution of the alkali cinnamate can be performed by the batchwise, semi-batchwise or continuous operation. Perkin reaction, etc. Cinnamic acid and its derivatives have a numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors. 1. The samples were separated by a LiChrospher RP-18 column with water-acetonitrile-methanolacetic acid (61:34:5:0.1 or 80:15:5:0.1, v/v) as t … The present invention is further illustrated by the following Examples and Comparative examples. Cinnamic acids are technically important as materials for perfumes, photosensitive polymers and various organic or biochemical products. The cinnamate esters useful for the practice of the process of this invention comprise those of the following formula: (wherein n is an integer of l to 5, R1 is hydrogen or at least one kind of substituent on the aromatic ring and represents, for example, halogen, hydroxyl, alkyl of l to 4 carbon atoms or alkoxy of l to 4 carbon atoms. Consequently cinnamic acid thus obtained was 14.6 grams (98.5% yield) and had purity of above of 99.9%.

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