Abstract
Ultraviolet irradiation of N‐phenylurethane (I) solutions with wavelength 253,7 nm resulted in the formation o polymeric material, the characteristic pattern of monomeric products associated with Photo‐FRIES‐type rearrangements [→ ethyl anthranilate (II), ethyl p‐aminobenzoate (III)], and accompanying dissociation products [→ aniline (IV)].N‐Phenylthiourethance (V) showed no tendency to undergo Photo‐FRIES‐type rearrangements. Formation of polymeric material and aniline (IV), and in the presence of molecular oxygen, cyclodehydrogenation to the 2‐ethoxy‐benzthiazol (VI) as well as a ready exchange of the sulfure atom in V by oxygen occurred instead.