Alkaline hydrolysis of nuclear-substituted ethyl cinnamates. Cumulative effects of substituents was written by Jones, Brynmor;Watkinson, J. G.. And the article was included in Journal of the Chemical Society in 1958.HPLC of Formula: 6972-61-8 This article mentions the following:
The introduction of substituents, even at the ο-position, causes no change in the nonexponential entropy term in the Arrhenius equation. The cumulative effect of 2 substituents in the 2- and 4-, and also in the 3- and 5-positions are additive, giving log10A 9.8-10.0, but in other positions there are sometimes large significant variations in the energies of activation compared with that calculated by ΔE’ = 2.303 RT log10k/k0, e.g. the factor 100 kcalculated/kobs. = 50 for Et 2,3-dimethoxycinnamate, and 58 for Et 2,3,4-trimethoxycinnamate, which indicates steric interference with mesomeric electron release from the 2-position, as confirmed by the analogous case of the 4-position in Et 3,4,5-trimethoxybenzoate where the factor = 25. Slight significant deviations for 3,4-dialkoxycinnamates may be due to steric and/or polar interactions. Hydrolyses were carried out at 24.8° and other temperatures in 85.4% aqueous EtOH, the initial concentrations of CO2-free NaOH and ester were equal at 0.05M, and the reactions strictly 2nd order. New compounds prepared via the substituted BzH and esterification are Et m-methylcinnamate, b10 146°, Et 2,4-dichlorocinnamate, b5 162° and m. 53.5°, Et 3,5-dichlorocinnamate, b12 178°, and m. 74°, Et 3,6-dichlorocinnamate, b2 156° and m. 56°, Et 3-chloro-4-methoxycinnamate, b4 170° and m. 61° (3-chloro-4-methoxycinnamic acid m. 244°), Et 3-methyl-4-methoxycinnamate, b11 184° and m. 36.5° (3-methyl-4-methoxycinnamic acid m. 201°), Et 2,3,4-trimethoxycinnamate, b14 207° and m. 50°, and Et 4-ethoxy-3-methoxycinnamate, m. 109.5° [4-ethoxy-3-methoxycinnamic acid m. 200° (decomposition)]. In the experiment, the researchers used many compounds, for example, 3-(2,4-Dimethoxyphenyl)acrylic acid (cas: 6972-61-8HPLC of Formula: 6972-61-8).
3-(2,4-Dimethoxyphenyl)acrylic acid (cas: 6972-61-8) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. At room temperature, ethers are pleasant-smelling colourless liquids. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive, and as a result they are useful as solvents for fats, oils, waxes, perfumes, resins, dyes, gums, and hydrocarbons. Vapours of certain ethers are used as insecticides, miticides, and fumigants for soil.HPLC of Formula: 6972-61-8
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem