F. Xi, W. Basset, O. Vogl
Dec 1, 1984
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0
Influential Citations
17
Citations
Journal
Macromolecular Chemistry and Physics
Abstract
Four new 5-methoxy-2H-benzotriazol-2-yl mono- or di-substituted resorcinols and phloroglucinols 5a,b and 6a,b were synthesized by reaction of resorcinol or phloroglucinol with 4-methoxy-2-nitrobenzenediazonium chloride in a 1:1 or 1:2 mole ratio and subsequent reductive cyclization with zinc and sodium hydroxide. The methoxy groups of all four compounds were cleaved with dry hydrogen bromide gas in dimethylformamide leading to the corresponding hydroxyl derivatives 7a,b and 8a,b in nearly quantitative yields. Unlike the reaction of phloroglucinol with a large excess of 2-nitrobenzenediazonium chloride, which gave the trisubstituted product, with 4-methoxy-2-nitrobenzenediazonium chloride no phloroglucinol derivative with three 5-methoxy-2H-benzotriazol-2-yl groups could be obtained. All the resulting products were characterized by their IR, 1H, and 13C NMR, and UV spectra. The resorcinol derivatives (both methoxy- and hydroxy-) Showed λmax of 345 nm and an absorption coefficients as high as 4 · 104 l · mol–1 · cm−1, and the phloroglucinol derivatives a λmax of 350 nm and an absorption coefficient as high as 4,5 · 104 l · mol−1 · cm−1.