Infrared spectra of heterocyclic compounds. IV. Infrared spectra of monosubstituted pyridine derivatives was written by Shindo, Hideyo. And the article was included in Pharmaceutical Bulletin in 1957.Recommanded Product: Ethyl pyrazine-2-carboxylate This article mentions the following:
The infrared spectra were determined and the maximum frequencies tabulated for 2-, 3-, and 4-substituted pyridines, in which the substituents were NO2, CN, Ac, CHO, CO2Et, CONH2, Br or Cl, C5H4N, Me, Et, MeO, and NH2 (38 compounds). All the compounds were prepared by well-known methods: reduction of the corresponding N-oxides gave the 4-O2N (m. 50°), 4-Cl (picrate, m. 144°), and 4-MeO (b30 92-4°) derivatives; perhydrol oxidation of the corresponding H2N derivatives gave the 3- and 2-O2N derivatives (m. 55° and 71°, resp.); ester condensation of the corresponding EtO2C derivatives gave the 2- and 3-Ac derivatives (b. 190° and 220°, resp.); and the Gattermann reaction on 3-H2N derivative gave the 3-Cl and 3-Br derivatives (b. 148-9° and 172-3°, resp.). The previously described exptl. method (C.A. 51, 5557b) for the infrared determinations was used. Results were discussed in their bearing on (1) the ring CH out-of-plane bending vibrations, which are in the region 700-900 cm.-1 and can be interpreted as analogous to the corresponding substituted benzenes, (2) the ring double-bond stretching vibrations, which show 2 bands between 1550 and 1620 cm.-1 that are directly related to the type of π-electron distribution on the ring, and (3) the electronic effect of ring N, which is shown as a frequency shift in the absorption of the substituent dependent upon its position in the ring. A series of weak absorptions at 990-1220 cm.-1 was found to be very characteristic for the type of substitution. The linear correlations between the frequencies and σ-values of the substituents in benzene derivatives could be extended to these pyridine derivatives by using the σ-values of 0.93, 0.62, and 1.02, resp., for 4-, 3-, and 2-positions. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Recommanded Product: Ethyl pyrazine-2-carboxylate).
Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) belongs to pyrazine derivatives. Pyrazine heterocycles and their benzo derivatives possess many interesting properties, including chemical reactivity profiles, and have diverse applications in total synthesis, medicine, chemical biology, materials, dyes, and imaging. Pyrazine heterocycles and their benzo derivatives possess many interesting properties, including chemical reactivity profiles, and have diverse applications in total synthesis, medicine, chemical biology, materials, dyes, and imaging.Recommanded Product: Ethyl pyrazine-2-carboxylate