Synthesis, Characterization and Antimicrobial Evaluation of some Thiazole-Derived Carbamates, Semicarbazones, Amides and Carboxamide
Khan, Nahed Nasser E. El-Sayed, Nawal Ali AL-Balawi, Ahmed M. Alafeefy Monirah A. AL ALShaikh, and Khalid Mohammed . 2016
This study comprises the synthesis and characterization of twenty thiazole-derived carbamates (3a-e), N-substituted amides (8a-h) and carboxamide (10) from 2-aminothiazoles (1a, b) via nucleophilic substitution reactions with activated carbonyl compounds including, chloroformates (2a-d), acid chlorides (7a-e) and glutaric anhydride (9), respectively. Sequential hydrazinolysis of carbamate (3e) and condensation with a variety of aldehydes and ketones (5a-d) afforded the corresponding semicarbazones (6a-d). Some selected synthesized compounds were subjected to in vitro antimicrobial evaluation against common pathogens including, Gram+ve bacteria Bacillus subtilis (NRRL B-543) and Staphylococcus aureus, Gram-ve bacteria Escherichia coli (NRRLB-21), yeasts-Candida albicans (NRRLY-477) and Saccharomyces cercvisiae (NRRL Y-567) and fungs Asperigillus niger (NRRL 599). Screening results revealed that most of the tested compounds possess good antimicrobial activity compared to standard drugs. The highest inhibitory effects against Gram-ve Escherichia coli, Gram+ve Staphylococcus aureus, yeast Candida albicans and fungus Aspergillus niger was displayed by amide (8g) bearing the thiophene moiety.
Some novel hydrazone derivatives 6a–o were synthesized from the key intermediate 4-Chloro-N-(2-hydrazinocarbonyl-phenyl)-benzamide 5 and…
This study comprises the synthesis and characterization of twenty thiazole-derived carbamates (3a-e), N-substituted amides (8a-h) and carboxamide (10) from 2-aminothiazoles (1a, b) via…
This work describes different strategies to desymmetrise 1,4-cyclohexadiene
derivatives with concomitant formation of a quaternary stereogenic centre.
Chapter 1 briefly describes the…