Dihydrocinnamic acid

Use 01 g. of the platinum oxide catalyst and 11 4 g, of pure cinnamic acid dissolved in 100 ml. of absolute alcohol. The theoretical volume of hydrogen is absorbed after 7-8 hours. Filter off the platinum, and evaporate the filtrate on a water bath. The resulting oil solidifies on cooling to a colourless acid, m.p. 47-48° (11-2 g.). Upon recrystallisation from light petroleum, b.p. 60-80°, pure dihydrocinnamic acid, m.p. 48-49°, is obtained. 

Simandi and Nagy studied the kinetics of the catalyzed hydrogenation of cinnamic acid (S) to dihydrocinnamic acid (SHj) under steady-state conditions 166). They concluded that the kinetically important reactions were the two successive transfers of hydrogen atoms, viz.. 

The major compounds extracted from labdanum were dihydrocinnamic acid (39), which is not found in other resins or gum resins and the relatively uncommon aromadendr-1 -ene (51) and ledene (61). Three minor diterpenes are also characteristic [40]. 

Aromatic acids (e.g., benzoic acid) and araliphatic acids (e.g., phenylacetic, cinnamic, and dihydrocinnamic acids) occur in numerous essential oils and have also been identified in the aromas of many foods. However, phenylacetic acid is the only acid that is used in significant quantities as a fragrance and flavor substance. 

Several applications of photoreactive peptides require the presence of a radionuclide to allow specific and sensitive detection of the photo-cross-linked conjugates. In several cases, radioiodination of tyrosyl moieties and radiolabeled Bolton-Hunter reagents have been used. However, the presence of a radiolabel within the benzophenone photophore is desirable, particularly when the objective is to identify the site of photo-insertion of benzophenone. To this end some radiolabeled, benzophenone-based compounds have been developed and used in peptide synthesis, in particular tritiated Phe(4-Bz) (Scheme 24)J2161 [1-14C-carboxy]-4-benzoylbenzoic acid,1221 and 4-benzoyl-(2,3-3H2)-dihydrocinnamic acid.[154l In addition, 4-(4-hydroxybenzoyl)phenylalanine (Scheme 25) has been directly radioiodinated with Na125I and Chloramine-T)151 ... 

Detailed kinetic studies of some aprotie systems were reported by Bamford s group. The kinetics of the polymerisation initiated by sodium salt of dihydrocinnamic acid in N-methyl-formamide exhibits a few interesting features. Typical conversion curves for D,L-phenyl alanine and y-benzyl-L-glutamate NCA s are shown in Fig. 10 taken from the paper by Ballard and BamfoRD (54). For a low concentration of the salt, the reaction is self-inhibited, i. e. a relatively rapid polymerisation ceases after a while (curve C) when a substantial fraction of the still... 

The ketocarbene is formed from 3-phenylpropanoyl chloride (dihydrocinnamic acid chloride) and diazomethane ring substituted dihydrocinnamic acids provide a route to substituted azulenes. Alternatively the keto group in (25) may be treated with a Grignard reagent for the introduction of alkyl substituents into the five-membered ring. 

A representative synthesis of the dihydrocinnamic acid ester (shown in Scheme B) begins with the bromination of vanillin (8). 

OH group may be assumed to form the anion/molecule complex 139 which, however, is non-reactive with respect to further tautomerization. Rather, this complex loses the entire carboxylate residue as the fragment ion m/z 255), leaving the phenolic unit as a quinoid neutral fragment (Scheme 37) °. In a further work, 3,4-dihydroxybenzyl carboxylates derived from stearic acid (cf. 140), dihydrocinnamic acid and phenylacetic acid were studied under NC1(NH3)-MS/MS conditions. In these cases, deprotonation was found to take place exclusively at the phenolic sites, owing to the increased acidity of hydroxyl groups in a catechol nucleus, in contrast to simple phenols. Heterolysis of the benzylic C—O bond, e.g. in ions [140 — gives rise to reactive anion/molecule complexes,... 

Beilstein Handbook Reference) AI3-00892 Benzenepropanoic acid Benzeneproplonic acid Benzylacetic acid BRN 0907515 CCRIS 3199 Dihydrocinnamic acid EINECS 207-924-5 FEMA No. 2889 Hydrocinnamic acid NSC 9272 Phenylpropanoic acid 3-Phenylpropanoic acid p-Phenylpropionic acid 3-Phenylpropionic acid. Fixative for perfumes, flavoring. Solid mp = 47-48° bp n 280° Xm = 247, 252, 257, 260, 263, 267 nm (MeOH) soluble in H2O (5.8 g/l), EtOH, Et20, CCl4, CHCI3, CS2, very soluble in CeHe, Greeff R.W. Co. Janssen Chimica Penta Mfg. 

Charlton [57] demonstrated the use of oxazolidinones as effective chiral auxiliaries the commercially available (4i )-benzyl and (4S)-isopropyl-2-oxazolidinones were /V-acylated with dihydrocinnamic acid to give N-acyloxazolidinones (54 and 55) in yields greater than 80%, Scheme (10). Diastereoselective alkylation with tert-butylbromoacetate gave in each case principally only one diastereomer (56 and 57, respectively) (de>95%). The oxazolidinone moiety could be removed by utilizing LiOH-H2C>2 without affecting the tert-butyl ester. The crude acid was reduced to the corresponding primary alcohol with BH3THF, then... 

The catalyst performances were measured in the hydrogenation of cinnamic acid to dihydrocinnamic acid and the catalyst activity given in ml H2/g catalyst/min. The reaction time for the hydrogenation reaction was 5 min in all experiments, and measured between the 3rd and 8th minute starting from the beginning of the H2-supply (Ref. 5). 

Different lots of commercially available, steam-activated and HNO3 washed carbons from beechtree wood were used as catalyst support. Tremendous catalytic activity variations were still found after impregnation with a H2PdCl6-solution using the low pressure hydrogenation of cinnamic acid to dihydrocinnamic acid as a model reaction /5/. 

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