The synthesis and stereoelectronic structure of 1- and 2-(trimethoxysilylmethyl)- and 1- and 2-(silatranylmethyl)benzotriazole

Abstract

Only 2-benzotriazolyl sodium is formed in the reaction of benzotriazole (BtH) with sodium methoxide. Its reaction with trimethyl- or trimethoxy-(chloromethyl)-silane affords a mixture of 1- and 2-(trimethylsilylmethyl)- 1 and 2, and 1- and 2-(trimethoxysilylmethyl) benzotriazoles, 3 and 4, which were separated into the individual isomers. trans-Etherification of the latter with tris-(2-hydroxyethyl)amine leads to 1- and 2-(silatranylmethyl)benzotriazoles 5 and 6. The electronic structures of the compounds prepared were investigated using IR, UV, multinuclear NMR spectroscopy, mass spectrometry, and X-ray diffraction. The organosilicon benzotriazole derivatives 1, 3 and 5 show a benzenoid structure, whereas 2, 4 and 6 have ortho-quinonoid structures.