Brown, Desmond J. published the artcileSpectra, ionization, and deuteration of oxazoles and related compounds, HPLC of Formula: 20662-83-3, the publication is Journal of the Chemical Society [Section] B: Physical Organic (1969), 270-6, database is CAplus.
The 1H N.M.R. spectra of oxazole, its derivatives and some related compounds in nonpolar, polar, and protonating media are discussed. The pKa values for oxazole (0.8, measured by the chem. shifts of H-2 in acidic media) and its derivatives show that the nucleus is far less basic than previously supposed, primarily owing to the powerful inductive effect of the O atom. The uv spectra of 2,5- and 2,4-diphenyloxazole indicate through-conjugation only in the former. This fact and other data suggest that oxazoles should be considered more as conjugated dienes than as fully aromatic compounds The rates for the 2-deuteration of simple oxazoles increase with the alkalinity; oxazole also undergoes 5- but not 4-deuteration under extreme conditions. On these grounds, the electron-distribution of the 3 C atoms of oxazole is clearly in the order 4 > 5 > 2. This is confirmed by the chem. shifts of the resp. protons and the pKa values of 2-, 4-, and 5-carboxyoxazole. Isoxazole (pKa – 2.03) is a much weaker base than previously reported.
Journal of the Chemical Society [Section] B: Physical Organic published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, HPLC of Formula: 20662-83-3.
Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem