2- -3-Chloro-cinnamate

From a mechanistic point of view, the behaviour of the P-halogenated enoates is of interest (24). (Z)-3-Chloro-cinnamate and (Z)-3-chloro-butenoate as well as (Z)-3-bromo-cinnamate consume in the presence of enoate reductase 2 mol NADH per mol instead of 1 mol as other enoates do. The products are the saturated halogen-free carboxylates (Reaction [14]). 

Unusual modes of dimerization of cinnamic acids have been found in the solid state photodimerization of the octadecyl esters of these acids. Bolt and co-workers have crystallized this ester of cinnamic acid in three different forms, one of which cyclized to an a-truxilic acid type of dimer, one of which was photo-inert, and one of which gave the 6-truxinic acid dimer. Two crystal forms of the ester of trans-p-chloro-cinnamic acid were isolated, one of which cyclized to an a-truxillic acid, the other being photo-inert. The long-chain ester group presumably modifies the crystal structure, and use of orienting groups of this type may allow the formation of other dimers not usually obtained in solid state dimerizations. 

Radicaloid substitution has not been extensively studied in the thiophene series. Molecular orbital calculations indicate that substitution should occur in the a-position. This has been found to be the case in the Gomberg-Bachmann coupling of diazohydroxides with thiophenes which has been used for the preparation of 2-(o-nitro-phenyl) thiophene, 2-(p-toluyl) thiophene, " " and 2-(p-chloro-phenyl)thiophene. " Coupling in the /8-position has been used for the preparation of 1,3-dimethyl-4,5-benzisothionaphthene (148) from 2-amino-tt-(2,5-dimethyl-3-thienyl)cinnamic acid (149). A recent investigation describes the homolytic phenylation of 2- and 3-phenyl-... 

Figure 4. Measured habits of crystals of -cinnamide (a) pure (b)- d) grown in the presence of (b) cinnamic acid, (c) p-chloro- or A-methyl-E-cinnamide, (d) a- or P-chloro-Z-cinnamide.

The reaction has also been applied to the conversion of vinyl bromides into acrylic acids, e.g. 1-bromo- and 1-chlorocyclooctene are converted into cyclooctene-1-carboxylic acid (ca. 98%) [3], 2-chloro-3,3-dimethylbut-l-ene yields 4,4-dimethylpent-2-enoic acid (95%), and tams-cinnamic acid is obtained (85%) from fran.v-p-bromostyrene. cis-p-Bromostyrene produces a mixture of cis- and trans-cinnamic acids in 38 and 42% yields, respectively [3]. In these reactions, benzyltri-ethylammonium chloride cannot be used as the phase-transfer catalyst, as it leads to the production of phenylacetic acid [3]. 

Palladium-charcoal has also been used in the presence of cinnamic acid as a hydrogen acceptor. Raney nickel alone and in the presence of hydrogen acceptors, the best being cyclohexanone, has also been utilized, although dehydrogenation did not occur with 6-chloro- and 6-nitro-l,2,3,4-tetrahydrocarbazoles." Selenium has also been used. ... 

Reaction of methyl / -chloro-(3-bromo-2,4,6-trimethyl)cinnamate (91) with MeS has been shown to give mixtures of elimination (92) and substitution (93) products (Scheme 20).81... 

H, Me) in trifluoroacetic acid solution exhibit two-component equilibrium mixtures 89A 89B (92KGS1689). For 4-methyl derivatives (R4 = Me), two fixed conformers (C(2)--NHR4 bond rotamers) of the cyclic tautomer 89B (E and Z) were detected. The equilibrium 89A 89B is rather insensitive to the nature of the substituent X (R2 = XC6H4). On passing from the aromatic aldehyde to the acetophenone derivatives, the equilibrium amount of the cyclic tautomer 89B increases. The cyclic protonated form of 2-chloro-6-nitrobenzaldehyde thiosemicarbazone could not be detected at all. It would be of interest to test the thiosemicarbazones of other 2,6-disubstituted benzaldehydes. Recently, it has been found (94KGS119) that the protonated cinnamic aldehyde thiosemicarbazone 89A (R1 = PhCH = CH, R2 = R3 = R4 = H) likewise does not form the cyclic tautomer 89B in trifluoroacetic acid solution. 

The analyses of the H. subflexa ovipositor extracts (171 revealed eight major components coinciding in retention times on SP-2340 and p-chloro cholesteryl cinnamate capillary columns (Figure 9) with 16 A1, Z9-16 A1, Z11-16 A1, (Z -7-hexadecen-l-ol acetate, (Z7-16 Ac), (Z)-9-hexadecen-l-ol acetate (Z9-16 Ac), (Z)-ll-hexadecen-l-ol acetate, (Zll-16 Ac), Z9-16 OH, and Z11-16 0H. Several other peaks were also variably present but, when present, each composed less than 1% of the total mixture. Mass spectral data confirmed the identity of the major components. 

Figure 3.3 Chromatogram of six common phenolic acids and cinnamic acid using C18 reversed-phase HPLC method. 1. Gallic acid 2. Protocatechuic acid 3. Chloro-genic acid 4. Caffeic acid 5./i-Coumaric acid 6. Ferulic acid 7. Cinnamic acid.

C18H11CI 10 Chloro-1,2-benzanthracene 20268-52-4 25.00 1 2144 2 30627 C18H1602 cinnamyl cinnamate 122-69-0 -figs 3-... 

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