Cinnamic acid aldehyde

Monohydric alcohols, aldehydes (including chloral hydrate), ketones, cinnamic acid, amines (2-naphthylaminc is odourless), nitrophenols (resemble both phenol and nitro-compound),... 

Reactions. Heating an aqueous solution of malonic acid above 70°C results in its decomposition to acetic acid and carbon dioxide. Malonic acid is a useful tool for synthesizing a-unsaturated carboxyUc acids because of its abiUty to undergo decarboxylation and condensation with aldehydes or ketones at the methylene group. Cinnamic acids are formed from the reaction of malonic acid and benzaldehyde derivatives (1). If aUphatic aldehydes are used acryhc acids result (2). Similarly this facile decarboxylation combined with the condensation with an activated double bond yields a-substituted acetic acid derivatives. For example, 4-thiazohdine acetic acids (2) are readily prepared from 2,5-dihydro-l,3-thiazoles (3). A further feature of malonic acid is that it does not form an anhydride when heated with phosphorous pentoxide [1314-56-3] but rather carbon suboxide [504-64-3] [0=C=C=0], a toxic gas that reacts with water to reform malonic acid. 

Pyrolytic Decomposition. The pyrolytic decomposition at 350—460°C of castor oil or the methyl ester of ricinoleic acid spHts the ricinoleate molecule at the hydroxyl group forming heptaldehyde and undecylenic acids. Heptaldehyde, used in the manufacture of synthetic flavors and fragrances (see Elavors and spices Perfumes) may also be converted to heptanoic acid by various oxidation techniques and to heptyl alcohol by catalytic hydrogenation. When heptaldehyde reacts with benzaldehyde, amyl cinnamic aldehyde is produced (see Cinnamic acid, cinnamaldehyde, and cinnamyl... 

Physical and Chemical Properties. The (F)- and (Z)-isomers of cinnamaldehyde are both known. (F)-Cinnamaldehyde [14371-10-9] is generally produced commercially and its properties are given in Table 2. Cinnamaldehyde undergoes reactions that are typical of an a,P-unsaturated aromatic aldehyde. Slow oxidation to cinnamic acid is observed upon exposure to air. This process can be accelerated in the presence of transition-metal catalysts such as cobalt acetate (28). Under more vigorous conditions with either nitric or chromic acid, cleavage at the double bond occurs to afford benzoic acid. Epoxidation of cinnamaldehyde via a conjugate addition mechanism is observed upon treatment with a salt of /-butyl hydroperoxide (29). 

Cinnamic Acid.—The reaction, which takes place when an aldehyde (aliphatic or aromatic) acts on the sodium salt of an aliphatic acid in presence of the anhychide, is known as Perkin s reaction, and has a ery wide application. Accoid-ing to the result of Fittig s researches on the properties of the unsaturated acids described below, the reaction occurs in two steps. The aldeh) de forms first an additive compound with the acid, the aldehyde caibon attaching itself to the n-carbon ii.e.i nevt the carbovyl) of the acid. A saturated hydiOKy-acid is formed, which is stable, if the a-carbon is attached to only one atom of hydrogen, as in the case of isobutync acid,... 

The aldol-like reaction of an aromatic aldehyde 1 with a carboxylic anhydride 2 is referred to as the Perkin reaction. As with the related Knoevenagel reaction, an o ,/3-unsaturated carboxylic acid is obtained as product the /3-aryl derivatives 3 are also known as cinnamic acids. 

Zimt, m. cinnamon. — weisser —, canella bark, canella. — chinesischer cassia bark. Zimt-. cinnamic cinnamon. -aldehyd, n. cinnamaldehyde, cinnamic aldehyde, -alko-hol, m. cinnamic alcohol, -blute,/. cinnamon flower, cassia bud. -bliltendl, n. cassia oil. zimtbraun, a. cinnamon-brown. Zimtcarbonsaure, /. carboxycinnamic acid, zimt-farbig, -farben, a. cinnamon-colored. Zimt-kaneel, m. canella bark, canella. -kassia, /. cassia bark, cassia, -kassienbl, n. oil of cassia. 

As shown in Schemes 10-44 and 10-45, two products may be formed in a Meerwein reaction Scheme 10-44 shows a simple aryl-de-hydrogenation of cinnamic aldehyde, whereas Scheme 10-45 shows an aryl-de-hydrogenation combined with the addition of HC1 to the double bond of the methyl ester of cinnamic acid. No systematic studies have been made as to which of the two products will be formed in a given reaction, what experimental conditions will favor one or the other product, and what substituents or other structural characteristics of the alkene influence the ratio of the two types of product. The addition product can, in most cases, easily be converted... 

The chiral center would be installed from either Unear carbamate 15 or branched carbamate 16 via the asymmetric addition of malonate anion to the 7i-allyl Mo complex reported by Trost et al. [11] to afford the branched chiral malonate derivative 17. Decarboxylation of 17 should provide the mono-carboxylic acid 18. Masa-mune homologation with 18 affords our common precursor 14. Linear carbamate 15 was obtained from the corresponding cinnamic acid, and branched 16 was prepared in one pot from the corresponding aldehyde. 

In this reaction the carbanion (103) is obtained by removal of an ot-H atom from a molecule of an acid anhydride (104), the anion of the corresponding acid acting as the necessary base the carbonyl acceptor is pretty well confined to aromatic aldehydes. The products are a/J-unsaturated acids, e.g. 3-phenylpropenoic(cinnamic) acid (105) from PhCHO/excess (MeC0)20/MeC02e at 140° ... 

The foregoing method has been adapted by Davalos and others (2004) using a conventional fluorescence microplate reader and applied to pure compounds (benzoic and cinnamic acids and aldehydes, flavonoids, and butylated hydroxyanisole) and to wines, as well as to commercial dietary antioxidant supplements. Eberhardt and others (2005) have also proposed a similar method for the determination of the antioxidant activity in broccoli. 

A. 0.02 M substituted benzaldehyde, 27 g acetic anhydride, 12 g fused K acetate in 250 ml round bottom flask with air condenser and CaCI2 tube. Heat on oil bath at 160° one hour and then at 175c for four hours. Pour into water (neutralize with Na carbonate and steam distill to recover unreacted aldehyde), cool, acidify and filter to get about 60% yield substituted cinnamic acid (I). 

For the reduction of nitro-compounds containing a group which may be attacked by nascent hydrogen, as, for example, an aldehyde group, an unsaturated side chain, and so on, special methods must he applied. In such cases ferrous hydroxide or iron powder (cf. Chap. VII. 5, arsanilic acid) are often used. The reduction is carried out thus a weighed amount of ferrous sulphate is caused to act, in the presence of alkali (potassium or sodium hydroxide, baryta), on the substance to he reduced. In this way it is possible to reduce, for example, o-nitro-benzaldehyde to aminobenzaldehyde, and o-nitrocinnamic acid to amino-cinnamic acid. 

Cinnamic acid synthesis from aryl aldehyde and acetic anhydride. 

Lignin has a complex structure that varies with the source, growing conditions, etc. This complex and varied structure is typical of many plant-derived macromolecules. Lignin is generally considered as being formed from three different phenylpropanoid alcohols— coniferyl, coumaryl, and sinapyl alcohols, which are synthesized from phenylalanine via various cinnamic acid derivatives and commercially is sometimes treated as being composed of a Cg repeat unit where the superstructure contains aromatic and aliphatic alcohols and ethers, and aliphatic aldehydes and vinyl units. 

Chlorophyll, 295 Chlorotil s, 135, 140 m-Chlorotoluene, 182,183 Chloitoluron, 292 Chlorzoxoneacetaminophen, 264 4 -Cholettenone, 74 Cholestanyl silica, 158 Cholesterol, 283, 295 Cholinesterase, 293 Chromatographic enzyme reactor, 291 Chrysene, 69, 105, 107 Cinnamic acid, 293 Cinnamyl acetate, 198 Cinnamyl alcohol, 198 Cinnamyl aldehyde, 198 dausius-Mosotti fimction, 208 Qindamycin, 297 Clonazqmm, 195 Clusters of hetaeron, 250 Coating of polar adsoibent by polar solvent, 86... 

Hydrogenation of benzaldehyde yields benzyl alcohol, condensation with aliphatic aldehydes leads to additional fragrance substances or their unsaturated intermediates. Unsaturated araliphatic acids are obtained through the Perkin reaction, for example, the reaction with acetic anhydride to give cinnamic acid. 

Cinnamomum aromaticum Nees. C. cassia Presl. Gui Zhi (Cinnamon) (twig, bark) Cinnamic aldehyde, cinnamyl acetate, cinnamic acid, eugenol, phellandrene, phenylpropyl alcohol, coumarin, cinnamic aldehyde, orthomethylcoumaric aldehyde.33-49-254-435-510 Antibacterial, vasodilatation, aromatic stomachic, astringent, tonic, analgesic, stimulate human lymphocytes to proliferate. 

Two mechanisms have been proposed for the Knoevenagel reaction. In one, the role of the amine is to form an imine or iminium salt (378) which subsequently reacts with the enolate of the active methylene compound. Under normal circumstances elimination of the amine would give the cinnamic acid derivative (379). However, when an o-hydroxy group is present in the aromatic aldehyde intramolecular ring closure to the coumarin can occur. The timing of the various steps may be different from that shown (Scheme 118). 

The Perkin synthesis of cinnamic acids is considered to involve reaction of the enolate anion derived from the acid anhydride with the aldehyde, giving rise to the alkoxide (391). Intramolecular acylation follows and the resulting /3-acyloxy derivative undergoes elimination to the unsaturated acid (Scheme 125). 

Aromatic aldehydes lake up keiene in the presence of potassium acetate in the manner of a Perkin reaction. The producl is a cinnamic acid ... 

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