The photochemical and thermal reactions of aromatic Schiff bases (SB) prepared from o- aminophenol and aldehydes and from 0-aminophenol and ketones are compared. All SBs are converted by light into the corresponding benzoxazoliies. For the SBs derived from aldehydes, benzoxazoline formation is a prerequisite to convert them by a second photon into benzoxazoles. In some cases oxygen is not required for this second reaction step. ...
![2-(4-methoxyphenyl)-2,3-dihydrobenzo[d]oxazole Structure](https://image.chemsrc.com/caspic/447/673435-36-4.png)