Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB32975/55A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bayer AG
Original Assignee
Bayer AG
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Filing date
Publication date
Application filed by Bayer AGfiledCriticalBayer AG
Publication of GB786925ApublicationCriticalpatent/GB786925A/en
Pharmaceuticals Containing Other Organic And Inorganic Compounds
(AREA)
Abstract
The invention comprises 1 : 4-thiaxanthone quinone and the preparation thereof by oxidizing 1 : 4-dihydroxythiaxanthone with bromic acid or salts thereof. The preparation may be carried out within the temperature range 0-100 DEG C. and preferably at room temperature. The bromic acid is preferably employed as an alkali metal salt, e.g. the potassium salt, in concentrated aqueous solution. The reaction may be carried out by adding an aqueous solution of the bromate with stirring into a suspension or solution of the dihydroxythiaxanthone in a dilutent or solvent such as acetic acid.