99849-00-0Relevant academic research and scientific papers
Preparation and properties of chloro-3-methoxycatechols-components of pulp bleaching effluents
Smith, Terrence J.,Wearne, Ross H.,Wallis, Adrian F. A.
, p. 911 - 920 (2007/10/03)
The preparation and properties are given for the seven chlorinated 3-methoxycatechols, several of which have been reported as components of pulp bleaching effluents. The 4- and 6-substituted compounds and the trichloro-3-methoxycatechol were obtained by direct chlorination of the parent catechol or its diacetate. The 5-substituted compound was prepared by the known addition of hydrochloric acid to 3-methoxy-ortho-benzoquinone, and further chlorination gave the 4,5- and 5,6-dichloro isomers. The diacetates of all seven compounds were separated by gas chromatography. Electron impact mass spectra and 1H and 13C NMR data for the diacetates are given.
13C and 17O NMR Study of Methoxy Groups in Chlorinated Di- and Trimethoxybenzenes
Knuutinen, J.,Kolehmainen, E.
, p. 315 - 317 (2007/10/02)
13C and 17O NMR data for the methoxy groups in isomeric 1,2-, 1,3- and 1,4-dimethoxybenzenes, 1,2,3-trimethoxybenzenes and most of their chlorinated derivatives and some related brominated compounds were measured for CDCl3 solutions.The 17O NMR chemical shifts show up to 60 ppm dispersion.Comparison between the compounds with and without adjacent chlorine atoms (2,6-di- and 2,4,6-trisubstitution) also showed a clear methoxy carbon chemical shift change.The number and position of the chlorine atoms in the aromatic ring give small but observable effects on the 17O NMR chemical shifts of the methoxy group if it is coplanar with the aromatic plane.Similarly, the degree and nature of the substitution have a minor effect (about 1 Hz) on the 1J(CH) direct coupling values.
