R. V. Talavdekar, K. Venkataraman
Nov 1, 1950
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Journal
Proceedings of the Indian Academy of Sciences - Section A
Abstract
SummaryThe bromination of the anilide,o-anisidide andp-anisidide of 2-hydroxy-3-naphthoic acid has been studied. The orientation of the bromine atoms has been determined and the effect of bromination on the shades and the fastness properties of the azoic shades produced from the brominated “naphthols” has been examined. By bromination of the anilide, the first bromine atom enters the naphthalene nucleus in the 1-position, and this can be readily removed by reducing agents. The second bromine atom enters the benzene nucleus in the 4′-position, while the third bromine atom attacks the naphthalene nucleus in the 6-position. Bromination of theo-anisidide gives a mixture of products; the first bromine atom enters the naphthalene nucleus, while the second bromine atom attacks partly the 3- and partly the 4-position ino-anisidine. Tribromination also gives a mixture in which 1∶3′∶4′-tribromo-2-hydroxy-3-naphth-o-anisidide predominates.The monobromo derivative of thep-anisidide of hydroxynaphthoic acid, obtained by the partial debromination of its dibromo derivative, is a mixture of 6-bromo- and 2′-bromo-2-hydroxy-3-naphth-p-anisidide. The dibromo compound, obtained by the partial debromination of the tribromo derivative, is 6∶2′-dibromo-2-hydroxy-3-naphth-p-anisidide.The N-6-bromo-2-hydroxy-3-naphthoyl derivatives of aniline,o- andp-anisidine have been prepared by condensing 6-bromo-2-hydroxy-3-naphthoic acid with the amines.All the brominated “naphthols” synthesized in the present work are characterized by the brightness and excellent fastness properties of the azoic shades.