%0 Journal Article %T Synthesis of pyrimido [4′,5′:5,6] [1,4] dithiepino [2,3- b] quinoxalines: Derivatives of a novel seven membered ring system %A Firoozi, Neda %A Bakavoli, Mehdi %A Eshghi, Hossein %A Ramezanian, Navid %A Akbarzadeh, Marzieh %J Phosphorus, Sulfur, and Silicon and the Related Elements %@ 1042-6507 %D 2017