Sulfuric Acid → HCID 20272673, compound

Participants

Reaction Steps

A mixture of 2.1 g of 4,8-diamino-1,5-dihydroxy-2-p-methoxyphenylanthraquinone (which can be prepared from 1,5-dihydroxy-4,8-dinitroanthraquinone, for method see German Offenlegungsschrift No. 3,007,198), 32 g of 60% H2SO4, and 3 g of active MnO2 is stirred for 1 hour at 20°, the mixture is filtered and 1 g of NaCl is added to the filtrate, which contains the corresponding quinoneimine. After stirring for half an hour, the mixture is poured into ice-water and the product is filtered off. The crude product is chromatographed over silica gel using petroleum ether/ether mixtures. The main product obtained is 4,8-diamino-6-chloro-1,5-dihydroxy-2-p-methoxyphenylanthraquinone, m.p. 310° (decomposition); Rf 0.41 (silica gel; 3:2 ether/petroleum ether). 4,8-diamino-7-chloro-1,5-dihydroxy-2-p-methoxyphenylanthraquinone, Rf 0.45 (silica gel; 3:2 ether/petroleum ether) is also formed.

Provenance & Evidence