- Selective halogenation of 1,4-benzoquinones and 1,4-naphthoquinones with copper(II) halide adsorbed on alumina
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1,4-Benzoquinone or 1,4-naphthoquinone and their derivatives have been halogenated selectively at quinonoid positions with copper(II) halide adsorbed on neutral alumina followed by refluxing in halobenzene to give mono-, di-, tri- and tetra-haloquinones.
- Singh,Khanna
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p. 2083 - 2089
(2007/10/02)
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- Reactive dyestuffs
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Triphendioxazine reactive dyestuffs of the general formula STR1 with the substituent definition given in the description, are outstandingly suitable for dyeing and printing materials containing hydroxyl groups or amide groups. They give red dyeings with high wet- and light-fastnesses.
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- Triphendioxazine dyestuffs
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Triphendioxazine dyestuffs of the formula STR1 having the substituent meanings specified in the descriptive part, are highly suitable for dyeing and printing hydroxyl- or amido-containing materials, in particular fibre materials, and produce wash-fast dyeings and prints.
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- Oxidation of Some 2-Methoxyphenols with Chlorous Acid
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Oxidation of 3-ethoxy-4-hydroxy-, 4-hydroxy-3-methoxy-5-methyl-, 3-chloro-4-hydroxy-5-methoxy-, and 2-hydroxy-3-methoxybenzaldehyde with chlorous acid gives, by oxidative aromatic ring cleavage between the oxygen-bearing carbon atoms, derivatives of (2Z, 4Z)-2,4-hexadienedioic acid in low yields.Chlorous acid oxidation of 2-methoxyphenol and 3-hydroxy-4-methoxybenzaldehyde yields methoxy-1,4-benzoquinone and 5,5-dichloro-6,6-dihydroxy-2-methoxy-2-cyclohexene-1,4-dione, respectively.The hydrate as well as the corresponding methyl hemiacetal undergoes base-catalyzed ring contraction to a derivative of 1-hydroxy-4-oxo-2-cyclopentenecarboxylic acid.The kinetics of the ring contraction of the hydrate was investigated in aqueous solutions in the pH range 1.15-3.65, where the rearrangement appears to be subject to specific base catalysis.
- Jaroszewski, Jerzy W.
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p. 2013 - 2018
(2007/10/02)
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