Heterocyclic analogs of 5,12-naphtacenequinone 13*. Synthesis of 4,11-diaminoanthra[2,3-b]furan-5,10-diones and sulfur-containing analogs

We have developed an effective method for the synthesis of 4,11-diaminoanthra[2,3-b]furan-5,10-dione and 4,11-diaminoanthra[2,3-b]-thiophene-5,10-dione derivatives based on the substitution of 4,11-alkoxy groups with n-butylamine and subsequent oxidative dealkylation of n-butylamino groups via treatment with tetrabutylammonium hydroxide in DMSO.