An efficient protocol for the synthesis of 7- and 8-functionalized 4- and 2-amino-3H-phenoxazin-3-ones and 2-amino-1H-phenoxazin-1-ones by oxidation of 2-aminophenols using hydrogen peroxide activated by ebselen is presented. We demonstrate that formation of the 2-amino-3H-phenoxazin-3-one core requires that the substituents present on one of the reacting substrate molecules be eliminated under oxidative reaction conditions.
Key words
catalysis - ebselen - heterocycles - peroxides - 2-aminophenols