[10-Acyldithranol dimers; new derivatives of the antipsoriatic dithranol; synthesis, characterization and biochemical...

With regard to the synthesis of 10-(omega-carboxyacyl)-derivatives dithranol 1 was reacted with the carboxylic acid dichlorides of succinic acid, glutaric acid, adipic acid and pimelic acid in toluene and collidin as a base. Instead of the expected derivatives the 10-acyldithranol dimers 5-7 were isolated as main products except for the reaction of succinyl chloride where only lactone 2 was formed. Moreover the 6-ring lactone 3 as a side product and traces of the 7-ring lactone 4 could also be isolated and characterized. All compounds revealed to be inhibitors of the enzyme glucose-6-phosphate dehydrogenase, indicating antipsoriatic activity.