Microwave assisted synthesis of some new thiazolopyrimidine, thiazolodipyrimidine and thiazolopyrimidothiazolopyrimidine derivatives with potential antioxidant and antimicrobial activity.
Biginelli reaction of ethyl acetoacetate, thiourea and the appropriate aromatic aldehyde was used to produce ethyl 4-aryl-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates, that reacted with bromomalononitrile to give ethyl 3-amino-5-aryl-2-cyano-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylates rather than the isomeric 7H-thiazolo[3,2-a]pyrimidines. Thiazolopyrimidine derivatives reacted with carbon disulphide to yield ethyl 9-aryl-7-methyl-2,4-dithioxo-2,3,4,9-tetrahydro-1H-thiazolo[3,2-a:4,5-d']dipyrimidine-8-carboxylates, that reacted with phenacyl bromide to produce ethyl 8-methyl-10-(4-methoxyphenyl)-3-substituted-5-thioxo-2(un)subatituted-10H-thiazolo[3'',2'':1',2']pyrimido[4',5':4,5]thiazolo[3,2-a]pyrimidine-9-carboxylates. The aforementioned reactions were carried out using both conventional chemical methods and with the assistance of microwave irradaition. Comparison between both methods showed that the microwave assisted method is preferable because of the time reduction and yield improvements achieved. The new compounds were tested for their biological activity as antioxidants, antibacterial or antifungal agents. Some of the new compounds were found to have moderate to good antioxidant and antimicrobial activities.
Chemistry Department, Faculty of Science, Cairo University, Cairo 12613, Egypt. mmmyousef@yahoo.com
Mohamed M
MM
Youssef
Mahmoud A
MA
Amin
D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004249:DNA Damage / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008872:Microwaves; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013844:Thiazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*
D000890:Anti-Infective Agents; D000975:Antioxidants; D011743:Pyrimidines; D013844:Thiazoles