The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Spectroscopic determination of constitution: Constitution of amino acids》. Authors are Ley, I. H.; Zschacke, F. H..The article about the compound:1-Piperidineacetic Acidcas:3235-67-4,SMILESS:OC(=O)CN1CCCCC1).Reference of 1-Piperidineacetic Acid. Through the article, more information about this compound (cas:3235-67-4) is conveyed.
This is part of an investigation of the absorption of light by amines and amino acids for the purpose of determining the constitution of the latter. Piperidylacetic acid has an absorption almost identical with that of AcONa. This precludes the usual open-chain formula for this acid because it is not probable that such a large group as C5H10N would be without effect on the absorption of AcOH. A special “”salt form”” is, therefore, assumed for the free acid-a “”neutralization”” of the amino group by the COOH group which influences the absorptive power. Measurements confirm that absorption is increased by the formation of the C5H10NHCOO ion when alkali is added to the acid. The absorption of the ester is greater than that of the salt; hence a different structure is indicated. The hydrochloride of the acid absorbs less strongly than the Na salt and more so than the acid. Slightly dissociated carboxylic acids absorb more strongly than completely dissociated salts. L. and Z. concluded that the structure of the aliphatic amino acids is probably expressed by the formula H….H2NRCOO, which contains Bredig’s “”Zwitter ion”” +NH3RCOO-. The inner metallic salt complexes like Cu glycine are assigned the formula OOCRNH2….Me.
Here is just a brief introduction to this compound(3235-67-4)Reference of 1-Piperidineacetic Acid, more information about the compound(1-Piperidineacetic Acid) is in the article, you can click the link below.
Reference:
Isoxazole – Wikipedia,
Isoxazole | C3H3NO – PubChem