www.jocpr.com Available online Journal of Chemical and Pharmaceutical Research, 2013, 5(8):16-21 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 16 Synthesis and in vitro antitumor activity of new benzothiazole and benzoxazole derivatives Manal M. Kandeel a , Eman K. A. Abdelall b , Mohammed K. Abd El Hamid a , Mohamed A. Abdelgawad b and John N. Philoppes b* a Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Cairo University, Egypt b Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Beni Suef University, Egypt _____________________________________________________________________________________________ ABSTRACT A series of benzothiazole and benzoxazole derivatives were synthesized from their parents whom bearing o- aminocyano groups then functionalized on amino group or cyano group. Some of the newly formed compounds were evaluated, in vitro, for their antitumor activity against MCF-7. Compound 4b was the most potent, showing activity IC 50 (0.011 µM ). Keywords: Antitumor activity, benzothiazoles, benzoxazoles, MCF-7 _____________________________________________________________________________________________ INTRODUCTION Formation of a hybride structure between benzene ring and five membered thiazole or oxazole ring resulted in the formation of benzothiazole or benzoxazole, respectively.[1] Benzothiazole and benzoxazole rings were found to possess different pharmacological activities such as anti‐viral, [2] anti‐bacterial, [3] anti‐microbial, [4] fungicidal [5] and antitumor [6-8] activities. Introducing aryl pharmacophore to benzothiazole and benzoxazole at position 2 exhibited a wide range of biological properties specially cytotoxic activity. [9,10] 2-phenylbenzothiazoles showed its antitumor activity by resembling the ATP antagonistic effects of the natural products. Moreover, they have tyrosine kinase inhibitory properties, [11] (Compounds I-IV) [12-14]. In this work, we synthesized new compounds containing benzothiazole and benzoxazole derivatives substituted at position 2 with phenyl ring containing substituted amino and/or carbonitrile derivatives aiming at forming compounds having potent antitumor activity against human adenocarcinoma cell line (MCF-7). S N CH 3 NH 2 R R= H, F S N R NH 2 R= H, CH 3 , Cl, I, Br S N N(CH 2 CH 2 Cl) 2 I II III IV O N NHCOCH 3 CH 3