Metal-free direct annulation of 2-aminophenols and 2-aminothiophenols with unactivated amides through transamidation: Access to polysubstituted benzoxazole and benzothiazole derivatives was written by Kumar, Vishal;Dhawan, Sanjeev;Bala, Renu;Girase, Pankaj Sanjay;Singh, Parvesh;Karpoormath, Rajshekhar. And the article was included in Tetrahedron in 2022.Name: 2,5-Dimethylbenzoxazole This article mentions the following:
Simple yet novel oxidant, metal and solvent-free green protocol for synthesizing differently 2-substituted 1,3-benzoxazoles I [R1 = Me, Ph, Bn, etc.; R2 = H, 6-Me, 5-Cl, etc.; X = O] and benzothiazoles I [R1 = Me; R2 = H, 5-Cl; X = S] from 2-aminophenol hydrochloride salt, unactivated amide as in situ carbon source was reported. Further, the hydrogen ion of hydrochloride played a crucial role in amide activation followed nucleophilic attack that through eliminations of amine as a side product, and de-hydrolysis step leads to final annulation. This versatile strategy was applicable to a wide variety of differently substituted o-aminophenols, unactivated aliphatic and aromatic amides, yielding the corresponding product in good to excellent yields in a single step. In the experiment, the researchers used many compounds, for example, 2,5-Dimethylbenzoxazole (cas: 5676-58-4Name: 2,5-Dimethylbenzoxazole).
2,5-Dimethylbenzoxazole (cas: 5676-58-4) belongs to benzoxazole derivatives. Benzoxazole derivatives have gained a lot of importance in the past few years because of their use in intermediates for the preparation of new biological materials. Due to its versatile biological properties, benzoxazole has been incorporated as an essential pharmacophore and substructure in many medicinal compounds.Name: 2,5-Dimethylbenzoxazole
Referemce:
Benzoxazole – Wikipedia,
Benzoxazole | C7H5NO – PubChem