European Journal of Medicinal Chemistry 2009-01-01

Synthesis of new 2-substituted pyrido[2,3-d]pyrimidin-4(1H)-ones and their antibacterial activity

B. Lakshmi Narayana, A. Raghu Ram Rao, P. Shanthan Rao

Index: Eur. J. Med. Chem. 44 , 1369-76, (2009)

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Abstract

2-Substituted-5,7-dimethyl pyrido[2,3- d]pyrimidin-4(1 H)-ones ( 8) were synthesized by oxidation of 2-substituted-5,7-dimethyl dihydropyrido[2,3- d]pyrimidin-4(1 H)-ones ( 7) which were in turn prepared from 2-amino-4,6-dimethyl nicotinamide ( 5) and substituted aryl aldehydes ( 6). 2-Amino-4,6-dimethyl nicotinamide ( 5) was prepared from ethyl cyanoacetate ( 1) via malonamamidine hydrochloride ( 3). The compounds were characterized by IR, NMR, MS and elemental analyses. Compounds 7 and 8 were screened for antibacterial activity against Gram positive and Gram negative bacteria. Dehydrogenated compounds ( 8) showed less antibacterial activity than the compounds 7. Among all the test compounds screened for antibacterial activity 7c (1.25 μg/ml) showed greater activity. All the synthesized compounds were found inactive when screened for antifungal activity at the concentration of 200 μg/ml.