STUDY OF THE ORIENTATION OF LITHIATION OF 1-ALKYLBENZOTRIAZOLES AND 2-ALKYLBENZOTRIAZOLES

Lithiation of 1-isopropylbenzotriazole (1) and subsequent reactions with iodine, with methyl iodide, and with D2O each gave complex mixtures of products indicating that the lithiation of 1 occurs at mainly three positions in the benzene ring. By contrast, lithiation of 2-isopropylbenzotriazole (11) occurs only at the alpha-CH of the isopropyl group. 1-Methyl-(14) and 1-ethylbenzotriazole (20) show lithiation both at the alpha-CH and to a lesser extent in the benzene ring. The products of the reactions are isolated or are characterized by GC/MS. Reaction mechanisms are suggested.