Step- and atom-economical synthesis of 2-aryl benzimidazoles via the sulfur-mediated redox condensation between o-nitroanilines and aryl methanols was written by Le, Huy X.;Nguyen, Khoa D.;Phan, Nam T. S.;Le, Ha V.;Nguyen, Tung T.. And the article was included in Tetrahedron in 2022.Name: (4-Methoxyphenyl)methanol This article mentions the following:
2-Nitroanilines and arylmethanols were used in the preparation of 2-aryl benzimidazoles I [R = 6-Me, 4-Me, etc.; R1 = Ph, 4-ClC6H4, etc.] in the presence of elemental sulfur and an amine. Mechanistic results indicated a dual role of sulfur as both oxidizing and reducing agents in this synthetic pathway. A variety of benzimidiazoles containing halogens, as well as trifluoromethyl, methoxy, and cyano groups, plus heterocycles were prepared in moderate-to-good yields. The utilization of more stable and available substrates in the absence of transition metals and other solvents offers a rapid and green synthesis of benzimidazoles. In the experiment, the researchers used many compounds, for example, (4-Methoxyphenyl)methanol (cas: 105-13-5Name: (4-Methoxyphenyl)methanol).
(4-Methoxyphenyl)methanol (cas: 105-13-5) belongs to ethers. The oxygen atom in ethers are more electronegative than carbon, thus the hydrogens which are alpha to the ethers are more acidic than the simple hydrocarbons. The unique properties of ethers (i.e., that they are strongly polar, with nonbonding electron pairs but no hydroxyl group) enhance the formation and use of many reagents. For example, Grignard reagents cannot form unless an ether is present to share its lone pair of electrons with the magnesium atom. Complexation of the magnesium atom stabilizes the Grignard reagent and helps to keep it in solution.Name: (4-Methoxyphenyl)methanol
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem