Collect. Czech. Chem. Commun. 1989, 54, 1388-1402

Some further 2-(4-substituted 1-piperazinyl)acetamides derived from 6,11-dihydrodibenzo[b,e]thiepin. Transformations of 6,11-dihydrodibenzo[b,e]thiepin derivatives into anthraquinones, anthrones and anthracenes

Hana Hulinská, Miroslav Ryska, Ivan Koruna, Jiří Holubek, Jan Taimr, Emil Svátek and Miroslav Protiva

Research Institute for Pharmacy and Biochemistry, 130 60 Prague 3


Reactions of the secondary amines I and VIII with chloroacetyl chloride gave the 2-chloroacetamides II and IX affording by substitution reactions with 1-methylpiperazine, 2-(1-piperazinyl)ethanol and 3-(1-piperazinyl)propanol in the title compounds III-V and X-XII. The starting amine VIII was prepared from the ketone XIV via XVII and VII. The product of 1,6-addition and the following dehydrogenation XVIII was obtained as a by-product of the reaction of XIV with 1-methyl-4-piperidylmagnesium chloride. Reaction of 2-fluorodibenzo[b,e]thiepin-11(6H)-one (XV) with sodium hydride in dimethylformamide and the following hydrolysis gave 2-fluoroanthraquinone (XXVII). An attempt at trapping the presumed dianion of the type B by treatment with methyl iodide and the following hydrolysis resulted in a mixture of XXVII and the anthracenes XXXI and XXXII. A similar reaction sequence starting from the ketone XIV gave the anthrones XXX and XXXIV, 9-methoxy-10-(methylthio)anthracene (XXXIII) (main product) and anthraquinone (XXVIII). Oxidation of XXXIII with m-chloroperbenzoic acid or hydrogen peroxide gave either the sulfone XXXV or XXXVI.