A series of pyridines, pyrimidinones, oxazinones and their derivatives were synthesized as antimicrobial agents using citrazinic acid (2,6-dihydroxyisonicotinic acid) as a starting material. α,β-Unsaturated ketones
3a–
c were condensed with cyanothio-acetamide in the presence of ammonium acetate to give 2-cyanopyridinethiones
4a–
[...] Read more.
A series of pyridines, pyrimidinones, oxazinones and their derivatives were synthesized as antimicrobial agents using citrazinic acid (2,6-dihydroxyisonicotinic acid) as a starting material. α,β-Unsaturated ketones
3a–
c were condensed with cyanothio-acetamide in the presence of ammonium acetate to give 2-cyanopyridinethiones
4a–
c, which were reacted with ethyl chloroacetate to yield the corresponding cyano esters
5a–
c. The esters
5a–
c were cyclized by action of sodium methoxide to aminoesters
6a–
c, which were aminolyzed with ammonia to corresponding aminoamide derivatives
7a-c. Also, the esters
6a–
c were hydrolyzed with NaOH to the corresponding sodium salt
8a–
c, which were treated with acetic anhydride to afford 2-methyloxazinones
9a–
c. The latter compounds were treated with ammonium acetate to afford 2-methylpyrimidinones
10a–
c, followed by methylation with methyl iodide to yield 2,3-dimethyl-pyrimidinones
11a–
c. The antimicrobial screening showed that many of these compounds have good antibacterial and antifungal activities comparable to streptomycin and fusidic acid used as reference drugs.
Full article