SYNTHESIS OF DIBENZO[D,F]-1,2-SELENA AND DIBENZO[D,F]-1,2-THIAZEPIN-3-ONES DERIVATIVES, BIS-HOMOEBSELEN

Dibenzo[d,f]-1,2-selena and -1,2-thiazepin-3-ones derivatives were pre pared from the corresponding 2-alkylselanyl- and 2-alkylsulfanylbiphen yl-2'-carboxamides or their diselenide or disuifide derivatives. These new seven-membered seleno-compounds are homologues of Ebselen (PZ51) (1) which exhibits glutathion peroxidase activity. Bis-homologues of P Z25 (2) were also synthesized. Synthesis of benzo[c]selenocoumarin via a directed ortho metalation-boronic acid cross-coupling reaction and it's ring-opening reaction are the first step of the synthetic pathway .