A NEW SYNTHESIS OF 2-METHYLENEAZIRIDINES

A new synthetic route leading to 2-methyleneaziridines has been develo ped by base-induced 1,2-dehydrobromination of 2-(bromomethyl)aziridine s. Several base-solvent pairs did not lead to 2-methyleneaziridines. O nly potassium tert-butoxide in tetrahydrofuran afforded 2-methyleneazi ridines in competition with the substitution products, i.e. 2-(tert-bu toxymethyl)aziridines. Various attempted functionalizations of 1-(aryl methyl)-2-methyleneaziridines failed, but they proved to be excellent substrates for the synthesis of beta-lactam derivatives, i.e. 1-(arylm ethyl)-2-iminoaze-tidines, through ring expansion with azides carrying electron-withdrawing substituents.