Abstract
Background: Pyranopyrazole derivatives has vital role in the class of organic compounds because of their broad spectrum of biological as well as pharmacological importance.Results: Our current goal is the [3+3] Cycloaddition of benzoyl isothiocyanate and pyrazolone 1 undergo oxidation cyclization producing pyrazoloxadiazine 3. The diol 5 was obtained as a condensation of two equivalent of 1 with thiopene-2-carboxaldhyde in acetic acid above sodium acetate mixture. When the condensation carried out in presence of piperidine under fusion the unsaturated ketone 4 was obtained. The cyclocondensation of pyrazolone 1 and pyruvic acid derivative in the presence of aminotive reagent resulted in pyrazolo pyrimidine 7. The pyrazolo pyran derivative 11 was resulted from the [3+3] cycloaddition of 1 and cinnamic acid. ᴽpyrone derivative was prepared by acylation of 12 with to equivalent of acetic anhydride. Phthalic anhydride undergoes arolyation using zinc chloride as a catalyst. The cyclic keto acid 23 was synthesized by the action of succinic anhydride on 12 in acetic medium. Cinnamic acid and 12 leads to pyrazole derivative 24 through Michael reaction. All of the tested compounds showed good microbial activity against pathogenic microorganisms. Newly synthesized compounds were screened for their antioxidant activity. Some of tested compounds exhibited promising activities.Conclusions: The newly synthesized compounds were found to be potent towards antioxidant activity. Moreover, the results showed that nearly a compound 5 was found to be the most potent levels of activity. Additionally, compounds 13, 14, 16, 22, 23 and 24 were found to have moderate activity. While compound 14 was found the lowest potent levels.
Development of a general, enantioselective organocatalytic Mukaiyama–Michael reaction with α,β-unsaturated aldehydes
