Quinone Chemistry. Reaction of 2,3-Dichloro-1,4-naphthoquinone with o-Aminophenols under Various Conditions

Article abstract of DOI:10.1021/jo01299a024

The reaction of 2,3-dichloro-1,4-naphthochinone (1) and o-aminophenols (2) under various reaction conditions was reinvestigated.Despite earlier literature, 1 and 2a in alcohol react to give a mixture of 6-chloro-12a-hydroxy-5H-benzophenoxazin-5-one (4a), 6-chloro-12a-alkoxy-5H-benzophenoxazin-5-one (5), 6-chloro-5H-benzophenoxazin-5-one (7a), 2-amino-3H-phenoxazin-3-one (8) and triphenodioxazine (9a).Contradictory to earlier findings, 1 and 2a in MeOH/KOH afford 7a but the highest yield of the compound is achieved by using EtOH or MeOH and anhydrous potassium acetate.A probable mechanism for the formation of all reaction products is presented and detailed spectroscopic data of all compounds are given.