SYNTHESIS, OF SOME NEW 4-OXO-4H CHROMENES Deriratives BEARING HETEROCYLIC SYSTEMS FROM HYDRAZONECABODITHIOIC ACID AND THIOCARBYDRAZONE.

elfayome, Ali; Tark El-Sayed Ali; Salah Abdel Aghfaar Abdel-Aziz; Hafez Metwali El Shaaer; Faten Ismail Hanafy;