Meisenheimer-type adducts from thiophene derivatives. Part 7. Interdependence of 13C NMR, thermodynamic and kinetic data was written by Dell’Erba, Carlo;Sancassan, Fernando;Novi, Marino;Spinelli, Domenico;Consiglio, Giovanni. And the article was included in Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) in 1991.HPLC of Formula: 42137-24-6 This article mentions the following:
A 13C NMR study has been carried out in (CD3)2SO on the thiophene derivatives I (X = H, Ac, CN, etc.; R = H) and II (same X, R) and the related Meisenheimer adducts III and IV. The data obtained, and in particular the sums of the chem.-shift changes (âÎÎ? at C-3, C-4 and C-5, accompanying the formation of the adducts, are compared with the corresponding data previously obtained for analogous substrates I (same X, R = MeO) and II (same X, R = MeO) and adducts III and IV. The four series of âÎÎ?values are then examined in the light of the already reported thermodn. (Ke) and kinetic (k1) constants for the formation of the adducts. For a given X-substituent, log Ke values increase linearly as the corresponding absolute âÎÎ?values decrease. On these grounds, the smaller Ï-electron-d. rearrangement accompanying the formation of gem-dimethoxy adducts emerges as an important factor, contributing to the larger observed Ke values. A further outcome is that, within a single series of adducts, a linear relationship of either log Ke or log1 with âÎÎ?holds only when excluding the terms with X = Ac or NO2. Such findings are interpreted on the basis of the two-component nature of the substituent R effects: while for the nitro and the acetyl substituents the Ï-electron acceptor component is prevalent, the stabilizing effect of the other substituents is due mainly to a charge-dipole interaction. The anal. of some literature data for the benzene series fits the above conclusions. In the experiment, the researchers used many compounds, for example, 4-Nitrothiophene-2-carbonitrile (cas: 42137-24-6HPLC of Formula: 42137-24-6).
4-Nitrothiophene-2-carbonitrile (cas: 42137-24-6) belongs to nitriles. Trimerization of aromatic nitriles requires harsh reaction conditions, high temperatures, long reaction times, and pressure. Some nitriles are manufactured by heating carboxylic acids with ammonia in the presence of catalysts. This process is used to make nitriles from natural fats and oils, the products being used as softening agents in synthetic rubbers, plastics, and textiles and for making amines.HPLC of Formula: 42137-24-6
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts