In organic chemistry, atoms other than carbon and hydrogen are generally referred to as heteroatoms. The most common heteroatoms are nitrogen, oxygen and sulfur. Now I present to you an article called Proximity effects in pyridines. Proton chemical shifts in substituted methyl pyridinecarboxylates, published in 1975, which mentions a compound: 455-70-9, mainly applied to pyridinecarboxylate NMR proximity effect; substituent effect NMR pyridinecarboxylate, HPLC of Formula: 455-70-9.
The chem. shifts in 6 series of substituted Me pyridinecarboxylates were measured and interpreted in terms of proximity effects. The shifts for ring H ortho and para to the substituent were explained by additive ester, nitrogen, and substituent effects. The results for meta H indicated substituent-nitrogen interactions, especially when both substituent and H were adjacent N. Similar results were obtained for the ester H.
Here is just a brief introduction to this compound(455-70-9)HPLC of Formula: 455-70-9, more information about the compound(Methyl 5-fluoro-3-pyridinecarboxylate) is in the article, you can click the link below.
Reference:
1,3-Benzodioxole – Wikipedia,
Dioxole | C3H4O2 – PubChem