Synthesis and antitumour activity of certain pyrido[2,3-d] pyrimidine and 1,8-naphthyridine derivatives

In an effort to establish new candidates with improved anticancer activity, we report here the synthesis of various series of 2,4,5,7-tetrasubstituted pyrido[2,3-d]pyrimidines and their related isosteres substituted 1,8-naphthyridines. The cytotoxic activity of the newly synthesised compounds against human breast cancer cell line, MCF7 was investigated. Most of the tested compounds exploited potent to moderate growth inhibitory activity, in particular 7-(4-chlorophenyl)-5-(3-nitrophenyl)pyrido[2,3-d]pyrimidin-4-amine exhibited superior potency to the reference drug doxorubicin (IC50 = 7.54 and 8.48 mu M respectively).