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 Heteroaromaticity. 8. The influence of N-oxide formation on heterocyclic aromaticity, published in 1993-09-10, which mentions a compound: 14248-66-9, mainly applied to Bird aromaticity index heterocyclic N oxide, COA of Formula: C7H8N2O3.
A recently described aromaticity index(author, 1992) has been used to examine the changes in the aromaticity of nitrogen heterocycles that accompany their N-oxidation Some instances are noted where there is an unforeseen increase in aromatic character. The aromaticity indexes is isomeric furoxans can be a useful indication as to their relative stabilities.
If you want to learn more about this compound(3,5-Dimethyl-4-nitropyridine 1-oxide)COA of Formula: C7H8N2O3, you may wish to communicate with the author of the article,or consult the relevant literature related to this compound(14248-66-9).
Reference:
Isoxazole – Wikipedia,
Isoxazole | C3H3NO – PubChem