Acryloyl isothiocyanate skeleton as a precursor for synthesis of some novel pyrimidine, triazole, triazepine, thiadiazolopyrimidine and acylthiourea derivatives as antioxidant agents

ABSTRACT

The reactions of 2-cyano-3-pyrazolylpropenoyl isothiocyanate derivative 2 with some mono- and bidentate nucleophiles namely, dodecan-1-amine, 6-aminothiouracil, hydrazine, phenylhydrazine, phenylurea, semicarbazide, and thiosemicarbazide, in addition to some derivatives of hydrazides, have been investigated to obtain some valuable heterocyclic skeletons gathering with a pyrazole core, viz. pyrimidine, triazole, triazepine, thiadiazolopyrimidine as well as acylthiourea derivatives. Hydrazinolysis of 2 was found to provide a mixture of thiosemicarbazide, diheterylazine, and triazepine derivatives. Treatment of 2 with phenylhydrazine was mainly dependent on the reaction conditions to produce a mixture of pyrimidinethione and triazole derivatives at room temperature or the triazepine derivative at heating conditions. The antioxidant activity screening of these compounds disclosed that pyrimidinethione derivatives 9 and 13 exhibited the most potency.

GRAPHICAL ABSTRACT

KEYWORDS:

• Isothiocyanate
• thiadiazolopyrimidine
• propenoyl chloride
• acylthioureas
• antioxidant

Acknowledgment

The authors would like to express their gratitude for Dr. Mosad A. Gharib, Associate Professor of Medicinal Chemistry, Theodor Bilharz Research Institute, Egypt.

Disclosure statement

No potential conflict of interest was reported by the author(s).