Rapid and efficient synthesis of 2,2-dimethylaminobenzazoles and 2,2-dimethylaminoazoles in a sustainable way

Reactions of 2–aminophenol, 2–aminobenzenethiol and other 2–substituted anilines (Scheme 1), ethylene amines and amino acid containing 1,2 amino hydroxy groups (Scheme 3) with TBTU [2–(1H–benzotriazole–1–yl)–1,1,3,3–tetramethyluroniumtetrafluoroborate], easily formed corresponding benzazoles (single crystal X–ray structure) and azoles attached with a dimethyl amino group at 2–position via a guanidine intermediate which cyclizes and aromatises by eliminating one dimethylamino group to afford benzazoles and azoles. The nobality of the synthesis is, single step and can occur at ambient temperature.