Synthesis and Pharmacological Evaluation of 1-(4-Chlorobenzyl)-6-Substituted 4-Oxo-Quinolin- 3-(N-Substituted/N, N-Disubstituted) Carboxamides

Asmita Gajbhiye1, Rajanna Ajumeera2, Shailendra Patil3 and G. Achaiah4

¹Department of Pharmaceutical Sciences, Dr. H. S. Gour Vishwavidyalaya Sagar - 470 003 (India) ²Division of RHN, Indian Council of Medical Research, Ansari Nagar, New Delhi - 110 029 (India) ³Globus College of Pharmacy, Bangrasia, Bhojpur Road, Bhopal - 462 045 (India) ⁴Medicinal Chemistry Research Laboratory, University College of Pharmaceutical Sciences, Kakatiya University, Warangal - 506 009 (India)

A series of 1-(4-chlorobenzyl)-6-substituted 4-oxo-quinolin-3-(N-substituted/N,N-disubstituted)carboxamides were synthesized and characterized by spectral data. Antihistaminic activity of all the compounds was determined by measuring their ability to inhibit histamine induced contractions on isolated guinea pig ileum and the compounds 1-(4-chlorobenzyl)-6-methyl-4-oxo-N-pyridin-2-yl-1,4-dihydroquinolin-3-carboxamide(6h), 1-(4-chlorobenzyl)-4-oxo-N-pyridin-2-yl-1,4-dihydroquinolin-3-carboxamide(6a), 1-(4-chlorobenzyl)-3-[(4-methylpiperazin-1-yl)carbonyl]-6-methylquinolin-4(1H)-one(6j), have shown the percentage inhibition of 97.5, 90.4, and, 87.1 percent when compared to standard pheniramine maleate. Using the method of protection against histamine induced convulsions in conscious guinea pig, compounds 6a, 6h and 1-(4-chlorobenzyl)-6-fluoro-4-oxo-N-pyridin-4-yl-1,4-dihydroquinolin-3-carboxamide(6g), have exhibited bronchodilatory activity with 50.42, 48.63 and 45.70 percentage protection, which is better than the standard comparator aminophylline ( 43.34%) at the dose of 50 μmol.

Quinolone; bronchodilatory; antihistaminic; antiallerg