Synthesis of some new pyridine-2,6-carboxamide-derived Schiff bases as potential antimicrobial agents.
A series of pyridine-bridged 2,6-bis-carboxamide Schiff's bases has been prepared starting from 2,6-pyridinedicarbonyl dichloride (1) and L-alanine or 2-methyl-alanine methyl ester.The coupling of acid chloride 1 with L-alanine methyl ester hydrochloride -or 2-methylalanine methyl ester hydrochloride gave the corresponding 2,6-bis-carboxamide pyridine methyl esters 2a,b.Hydrazonolysis of 2 with hydrazine hydrate afforded the corresponding bis-hydrazides 3a,b. Treatment of 3a,b with appropriate aromatic or heterocyclic aldehydes afforded the corresponding pyridine- bridged 2,6-bis-carboxamide Schiff's bases 4a-f and 5a-f, respectively. The newly synthesized compounds 2-5 were screened for their bactericidal and fungicidal activities. Many of the obtained compounds exhibited significant antimicrobial activity, comparable to streptomycin and fusidic acid, which were used as reference antibiotic drugs.
Al-Omar
Mohamed A
MA
Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.
Amr
Abd El-Galil E
Ael-G
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis; D000890:Anti-Infective Agents / Q000138:chemical synthesis*; D000935:Antifungal Agents / Q000138:chemical synthesis; D008826:Microbial Sensitivity Tests; D011725:Pyridines / Q000737:chemistry*; D012545:Schiff Bases / Q000138:chemical synthesis*
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D011725:Pyridines; D012545:Schiff Bases