Chromone-3-sulphinic acids and their preparation

摘要

There are described novel chromone-3-sulphinic acids of the formula <IMAGE> in which A represents the remaining members of a benzene ring with which further carbocyclic C6-rings and/or a pyrone and/or a furan ring can be fused, it being possible for the benzene ring and/or the fused rings to be substituted. They can be prepared by reaction of enamine ketones of the formula <IMAGE> in which R<1> and R<2> denote, for example, C1-8-alkyl, with thionyl chloride. These chromone-3-sulphinic acids can be reacted further to give the corresponding sulphonic acids or bis(chromonyl) disulphides.