Kamelia M. El-Mahdy

Synthesis and Antimicrobial Activity of Some New Heterocyclic Schiff Bases Derived from 2-Amino-3-formylchromone

Some new hydrazone derivatives 3a–e have been obtained from 2-amino-3-formylchromone (1). Heterocyclization of thiocarbohydrazone derivative 3e via reaction with some electrophilic reagents afforded 1,2,4-triazoles 6–8 and 1,2,4-triazines 9–13. Condensation reactions of aldehyde 1 with o-aminoaldehydes and/or ketones afforded some new isolated and condensed heterocyclic systems 17, 19, and 20. The newly synthesized compounds were screened for their antimicrobial activity.

Synthesis and Biological Evaluation of Some New Pyrimidine Derivatives

New pyrimidine derivatives comprising azo, schiffs bases, chalcones, and chromene ring moieties were prepared.The newly synthesized compounds have been established on the basis of their m.p., TLC, FT-IR, UV-Vis ,1H-NMR data and element analysis. These compounds were screened for their antimicrobial and in vitro antioxidant properties. The results of this investigation revealed that these compounds are potent antimicrobial and antioxidant agent.

Synthesis, Characterization and ِAntimicrobial Activities of Some New Heterocyclic Schiff Bases Derived from Thiocarbohydrazide

The reaction of prazolobenzothienopyrimidine-3-carbaldehyde 1 with thiocarbohydrazide afforded the Schiffs base 3. The latter compound reacted with some electrophilic reagents to give 1,2,4-triazoles 4-6 and 1,2,4-triazines 7-9. Treatment of compound 3 with 2-cyano-3,3-bis(methylthio)acrylonitrile gave the corresponding 5-amino-4-cyano-3-methylthiopyrazole derivative 11. The reaction of pyrazole 11 with carbon disulfide afforded dithioxopyrazolopyrimidine 12. Acylation of compound 11 by using acetic anhydride yielded acetamide 13. On the other hand, the cyclocondensation of pyrazole 11 with acetic anhydride in pyridine yielded pyrazolopyrimidine derivative 14. The reactivity of compound 11 towards formamide and phenylisothiocyanate to give the pyrazolopyrimidines 15 and 16 was studied. The newly synthesized compounds were screened for their antimicrobial activity.

Facile synthesis of novel carbothioylbis[1,2,4]triazolo [4,3-a]pyrimidine and carbothioylbispyrimido[2,1-c] [1,2,4]triazine derivatives

The versatile multifunctional hitherto unreported N′,N″-bis(5-cyano-6-oxo-4-phenyl-1,6-dihydropy- rimidin-2-yl)thiocarbohydrazide was prepared by the reaction of ethyl [(5-cyano-6-oxo-4-phenyl-1, 6-dihydropyrimidin-2-yl)thio]acetate with thiocarbohydrazide. Condensation of pyrimidinyl thiocarbohydrazide with carbon disulfide gave carbothioylbis[1,2,4]triazolo[4,3-a]pyrimidine. Several new heterocycles namely carbothioylbispyrimido[2,1-c][1,2,4]triazine derivatives have been synthesized by the reactions of pyrimidinyl thiocarbohydrazide with 1,2-dibromoethane, chloroacetyl chloride and diethyl oxalate. The mechanistic aspects for the formation of the newly synthesized compounds are discussed.