Synthesis of novel [3,1]-benzothiazepine and [3,1]- benzoxazepine derivatives with antitumoral activity

A new method for the synthesis of [3,1]-benzothiazepines and [3,1]- benzoxazepines from the reaction of C-allylanilines and isothiocyanates or isocyanates without the need for the isolation of any intermediate is described. The compounds were obtained in good to moderate yields and some exhibited cytotoxic activity against tumor cell lines. Benzothiazepines and benzoxazepines constitute important building blocks in pharmaceutical research while they can be found in many drugs and preclinical leads.1 The synthesis of different isomeric forms of these compounds by varying the position of the heteroatoms in their structures together with their unique pharmacological properties make the development of new methods for the synthesis of medium-sized heterocycles containing N, S and O atoms a subject of great interest. Thus, several isomers of benzothiazepine2 and benzoxazepine3 rings were already described and some of them exhibited a wide variety of pharmacological effects.