Abstract The reaction of 1-nitroso-2-naphthol with resorcin in glacial acetic acid and ether was studied. As oxidants nitric acid and lead (IV)-acetate were employed. In addition to already prepared benzo [a] phenoxazon-(9), and some of its derivates one—till this time not described—benzo [a] phenoxazone-(9)-12-oxid was isolated and identified. The reaction mechanism and the constitution of I are verified.
![benzo[a]phenoxazin-9-one Structure](https://image.chemsrc.com/caspic/236/731-72-6.png)
