The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《β-Amino acids. IV. β-Methionine and β-ethionine》. Authors are Birkofer, Leonhard; Storch, Ingeborg.The article about the compound:2-Bromo-3-methoxypropanoic acidcas:65090-78-0,SMILESS:O=C(O)C(Br)COC).Formula: C4H7BrO3. Through the article, more information about this compound (cas:65090-78-0) is conveyed.
cf. C.A. 49, 2317d. HO2CCHAcCH2CO2Et and NaH gave the Na salt, which with ClCH2SMe yielded EtO2CAc(CH2SMe)CH2CO2Et (I), b3 153° (2,4-dinitrophenylhydrazone, m. 92-3°). Refluxed 10 hrs. with 18% HCl I gave AcCH(CH2SMe)CH2CO2H, isolated as the Et ester (II), b3 123° (2,4-dinitrophenylhydrazone, m. 62-3°), as well as AcC(:CH2)CH2CO2H (2,4-dinitrophenylhydrazone, m. 210°), and 3-acetyl-γ-butyrolactone (2,4-dinitrophenylhydrazone, m. 193°). I refluxed with HCl only 4 hrs. gave mono-Et 2-acetyl-2-(methylthiomethyl)succinate, b0.001 115-17° (2,4-dinitrophenylhydrazone, m. 169-70°). I was saponified with Ba(OH)2 to HO2CCH(CH2SMe)CH2CO2H, m. 114-15°. II and HN3 in the presence of HCl gave β-methionine (III), m. 197-8° (picrolonate, m. 190-2°; 3,5-dinitrobenzoyl derivative, m. 200°). MeSCH2CH:CHCO2H, m. 58.5°, obtained from MeSCH2CHO and CH2(CO2H)2 (IV), gave III with NH3 in a sealed tube at 150-60°. EtSNa, obtained from EtSH with Na, and bromoacetal gave EtSCH2CH(OEt)2, converted by HCl to the aldehyde, b14 45-6°, which with IV gave EtSCH2CH:CHCO2H, which with NH3 in a sealed tube yielded β-ethionine (V), m. 198° (picrolonate, m. 180-3°). III and V do not react with aqueous ninhydrin, but give a blue color with it in 95% BuOH-5% 2N HOAc.
There is still a lot of research devoted to this compound(SMILES：O=C(O)C(Br)COC)Formula: C4H7BrO3, and with the development of science, more effects of this compound(65090-78-0) can be discovered.
Reference:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia