AM1 molecular orbital study of the transmission of electronic effects in the 5-membered heteroaromatics: proton and hydride ion affinities of 4- and 5-substituted (2-heteroaromatic)methyl anions and cations was written by Bean, Gerritt P.. And the article was included in Journal of Organic Chemistry in 1993.HPLC of Formula: 89281-44-7 This article mentions the following:
The proton and hydride ion affinities of a series of the benzyl-like anions and cations of 4- and 5-substituted 2-Me 5-membered heteroaromatic compounds have been calculated by the AM1 MO method. Calculations included para- and meta-substituted toluenes, similarly substituted 1,3-pentadienes, and 3-aza-1,3-pentadienes as various models for the possible pathways for the effect of the substituents to be transmitted to the reaction site. There was excellent correlation between the 4-substituted compounds and the m-toluenes and between the 5-substituted compounds and the p-toluenes. Compared to the other ring atoms, substituents at either the 4- or 5-position have little effect on the change in the charges on the heteroatoms in going to either the cation or anion of the heteroaromatic compounds Transmission of electronic effects is primarily through the carbon skeleton with little if any through the heteroatom. In the experiment, the researchers used many compounds, for example, 2-Methylthiazol-5-amine (cas: 89281-44-7HPLC of Formula: 89281-44-7).
2-Methylthiazol-5-amine (cas: 89281-44-7) belongs to thiazole derivatives. Thiazole is a five-membered, unsaturated, planar, π-excessive heteroaromatic containing one sulfur atom and one pyridine-type nitrogen atom at position 3 of the cyclic ring system. Thiazole sulfonation occurs only under forcing conditions: the action of oleum at 250 °C for 3 hours in the presence of mercury(II) sulfate leads to 65% formation of 5-thiazole sulfonic acid.HPLC of Formula: 89281-44-7
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica