An Efficient Synthesis of Novel Bioactive Thiazolyl-Phthalazinediones under Ultrasound Irradiation

Abstract

Novel 2-thiazolylphthalazine derivatives were efficiently synthesized under ultrasound irradiation, resulting in high yields and short reaction times after optimization of the reaction conditions. All prepared compounds were fully characterized using spectroscopic methods. They were screened for their antimicrobial activity against Gram-positive and Gram-negative bacteria as well as for antifungal activity. The antimicrobial activity profile of the tested compounds showed some promising results. The potent activity of compounds 4d, 7b (117% zone inhibition) and 7c (105% zone inhibition) against Salmonella sp., exceeding that of the reference drug Gentamycin is particularly noteworthy. In general, the newly synthesized thiazolylphthalazine derivatives showed higher antimicrobial activity against the tested Gram-negative bacteria than against Gram-positive bacteria and fungi.

Ultrasound-assisted transition-metal-free catalysis: a sustainable route towards the synthesis of bioactive heterocycles

“… 82 To realize this significance, a very beneficial and straightforward method for expedient access to various thiazole derivatives was developed by Farghaly et al ( Scheme 14 ). 83 By using a tertiary amine Et 3 N as the catalyst, the corresponding thiazole derivatives 54 and 57 derived from the ultrasound-assisted reaction of thioamide 51 and acetyl hydrazonoyl chloride 52 or ethyl ( N -arylhydrazono)-chloroacetates 55 have been accomplished in 84–92% and 83–85% yield respectively at 30–60 minutes. Compared to the traditional thermal method, ultrasound techniques allow for easy and clean isolation of the products in pure form in a relatively quick reaction time.…”

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“…The phthalazine derivatives were identified as 2.82% of 1, 4-Methanophthalazine, 1, 4, 4a, 7, 8, 8a-hexahydro-9, 9-dimethyl-, (1α, 4α, 4a α, 8a α) compound. Like the other members of the isomeric benzothiazine series, have been widely applied as therapeutic agents due to their anticonvulsant, cardiotonic, vasorelaxant and anti-inflammatory properties 29 . Copaene compound (2.74%) is similar to one component in Euphorbia macrorrhiza oil which serves as an antimicroorganism and anti-tumor 30 .…”

Surprising Chemistry of 6-Azidotetrazolo[5,1-a]phthalazine: What a Purported Natural Product Reveals about the Polymorphism of Explosives

“…It contains an equal number of carbon and nitrogen atoms, and its six nitrogen–nitrogen bonds encompass an azido group, a tetrazole ring, and a phthalazine ring. The realm of natural products includes one other phthalazine, the meroterpenoid azamerone ( 3 ), which was isolated from cultures of a marine species of the bacterium Streptomyces. − However, the only azide or tetrazole reported to be a natural product is ATPH.…”