Аннотация:For the first time, the possibility of photoinduced migration of the cymantrenylmethyl fragment in O-substituted quinazolinones from position 4 to 3 of the quinazolinone ring under irradiation with light by a mercury lamp having lmax = 365 nm is found. We have explored this possibility for carrying out the isomerization of the N-substituent in 1,2,3-triazoles as a new way to obtain 2,4-disubstituted 1,2,3-triazoles.