Cinnamic acid/cinnamate

Zimtrinde, /. cinnamon bark, zimtsauer, a. of or combined with cinnamic acid, cinnamate of. 

Catecholases and laccases may be differentiated by the use of substrate specificity tests and selective specific inhibitors (Walker and McCallion, 1980 Ferrar and Walker, 1996 Table C4.1.1). Salicylhydroxamic acid (SHAM), PVP, and/or cinnamic acids (cinnamic, p-coumaric, or ferulic) are probably the best choice for catecholase inhibitors, whereas cetyltrimethylammonium bromide (CETAB) has been found to inhibit most laccases. 

It is necessary to prepare first, o-nitro-phenyl-propiolic acid, which is itself obtained from o-nitro-cinnamic acid. Cinnamic ester (50 gms.) is nitrated by pouring gradually into cooled nitric acid (sp. g. 1-5). 

Arenediazonium o-benzenesulfonamide 89 was found to be a new and efficient reagent for the Heck-type arylation reactions of some common substrates containing C-C multiple bonds, i.e., ethyl acrylate, acrylic acid, acroleine, styrene, and cyclopentene <2006T3146>. The reactions are carried out in the presence of Pd(OAc)2 and afford arylated products, for example ethyl cinnamates, cinnamic acids, cinnamic aldehydes, and stilbenes, possessing an ( -configuration, and 1-arylcyclopentenes, in good to excellent yields (Equation 27). 

Cinnamic Acid.—Cinnamic acid, investigated by Brester,5 showed a similar behavior in the electrolysis of both the free acid and the neutral solutions of its salts. Lob 6 has reported an accidental observation on the formation of bromstyrene by electrolysis of cinnamic acid in the presence of potassium bromide. 

Oxidative dimerization of cinnamic acids Cinnamic acid itself is stable to TTFA in the presence of BF3 etherate but 4-alkoxycinnamic acids are converted by these two reagents in TFA-CH2CI2 to fused bislactones by a nonphenolic oxidative dimerization (equation I). A few natural products of this type are known. 

Phenyl acetic acid. Hydro cinnamic acid. Cinnamic acid or Phenyl acrylic acid Phenyl propiolic acid. Phenyl vinyl acetic acid. 

The NIICRs to benzoic acid, cinnamic acid, cinnamic aldehyde, methyl nicotinate and diethyl fuma-rate can be inhibited by peroral acetylsalicylic acid and indomethacin (Lahti et al. 1983, 1987) and by a topical application of diclofenac or naproxen gels (Johansson and Lahti 1988). The duration of inhibition by a single dose of acetylsalicylic acid can be as long as 4 days (Kujala and Lahti 1989). The mechanism by which non-steroidal anti-inflammatory drugs inhibit NIICRs in human skin has not been defined, but it is probably ascribable to the inhibition of prostaglandin metabolism. 

The principal constituent of the oil is methyl-eugenol, with some eugenol, free cinnamic acid, cinnamic aldehyde, cinnamic alcohol ( ), phellandrene, and cinnamyl-( )-cinnamate. 

An alternative method for the classical Knoevenagel-type preparation of cinnamic acids has been reported this came to light during a study of the bromine-induced decarboxylation of substituted cinnamic acids. Cinnamic acid derivatives can also be prepared by the palladium-catalysed coupling of methyl acrylate with electron-rich aryl iodidessimilarly 5-arylpenta-2,4-dienoic acids (29) can be synthesized from penta-2,4-dienoic acid and bromo-aryls. A Stobbe-type condensation between aromatic aldehydes and methyl propylidenemalonate leads to the , -unsaturated acids (30), probably via a 5-lactone intermediate. ... 

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