The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Vibration and electronic spectra of esters of polyenecarboxylic acids》. Authors are Kogan, G. A.; Ivanova, T. M.; Yanovskaya, L. A.; Kucherov, V. F.; Popov, E. M..The article about the compound:Ethyl 3-Ethoxy-2-Propenoatecas:1001-26-9,SMILESS:O=C(OCC)/C=C/OCC).Formula: C7H12O3. Through the article, more information about this compound (cas:1001-26-9) is conveyed.
The frequencies and integral intensities of bands in the ir and uv spectra and Raman spectra of polyene compounds X(CH:CH)nCOOEt (X = Me, OEt, COH, NO2, and CO2Et; n = 1-5) were investigated in a study of the mutual effect of functional groups of atoms through a system of conjugate bonds. Causes of changes in these parameters in the spectra of compounds in the basic and excited states were determined from an analysis of the data.
If you want to learn more about this compound(Ethyl 3-Ethoxy-2-Propenoate)Formula: C7H12O3, you may wish to communicate with the author of the article,or consult the relevant literature related to this compound(1001-26-9).
Reference:
Bromide – Wikipedia,
bromide – Wiktionary