Method for preparing 1,4-diaminoanthraquinones and intermediates thereof
AssigneeThe Clorox Company
InventorAlfred G. Zielske
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Abstract
Aminoanthraquinones are generally useful as dyes and coloring agents. But known methods of synthesizing unsymmetrically substituted 1,4-diaminoanthraquinones are tedious and complex. A simple and efficient method is provided for preparing 1,4-diaminoanthraquinones, particularly unsymmetrically substituted 1,4-diaminoanthraquinones, by means of novel monoamino-monotosyloxy-anthraquinones.
Claims11
A 9,10-anthraquinone having a tosyloxy group and an amino group substituted on one ring thereof, said amino group and said tosyloxy group being in a para relationship on said one ring.
A compound having the structure ##STR17## wherein R.sub.1 is hydrogen, alkyl, cycloalkyl or aryl, R.sub.2 is hydrogen, alkyl, cycloalkyl or aryl, and X is methyl, chloro, bromo or nitro.
A method of preparing a monoamino-monotosyloxy-anthraquinone comprising:
- providing a first compound having the structure ##STR19## admixing said first compound with an excess of a primary or secondary amine to form a reaction mixture, said amine having the formula R.sub.1 R.sub.2 NH wherein R.sub.1 is hydrogen, alkyl, cycloalkyl or aryl, and R.sub.2 is hydrogen, alkyl, cycloalkyl, or aryl, the reaction mixture including an organic solvent, when R.sub.1 and R.sub.2 are hydrogen, alkyl or cycloalkyl the organic solvent being methylene chloride, and when at least one of R.sub.1 and R.sub.2 is aryl the organic solvent being dimethyl sulfoxide;
- maintaining a reaction temperature of the reaction mixture at not greater than about 50.degree. C. when R.sub.1 and R.sub.2 are hydrogen, alkyl or cycloalkyl and at not greater than about 150.degree. C. when at least one of R.sub.1 and R.sub.2 are aryl;
- and
- isolating a reaction product from the reaction mixture having structure ##STR20##
A 9, 10-anthraquinone having two tosyloxy groups substituted on one ring thereof, said groups being in para relationship on one ring.
Dependencies are inferred from the claim text.