Synthesis, characterization and analgesic activity of new 4-arylhydrazono-3-methoxymethyl-2-pyrazolin-5-ones.
New 4-arylhydrazono-3-methoxymethyl-2-pyrazolin-5-ones (5a-j) and 4-arylhydrazono-3-methoxymethyl-1-phenyl-2-pyrazolin-5-ones (6a-j) were synthesized by the reaction of ten novel methyl 2-arylhydrazono-4-methoxy-3-oxobutanoates (4a-j) with hydrazine hydrate and phenylhydrazine, respectively. Treatment of 5a with acetic anhydride yielded 1-acetyl-4-arylhydrazono-3-methoxymethyl-2-pyrazolin-5-one (7). The structures of the tautomerically dynamic compounds were established by spectral data (IR, 1H-NMR, 13C-NMR, EIMS and CIMS) and elemental analysis. The analgesic activity of the title compounds was determined by the modified Koster's test. The most active compound was 4-[(4-chlorophenyl)hydrazono]-3-methoxymethyl-1-phenyl-2-pyrazolin-5-one (6c) demonstrating twice the activity (60%) exerted by the reference drug acetylsalicylic acid (ASA, 27%). The majority of the tested compounds were found to be more effective than ASA.
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Istanbul, Istanbul, Turkey.
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N
Ergenç
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G
Capan
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R
Demirdamar
D018712:Analgesics, Non-Narcotic / Q000138:chemical synthesis* / Q000494:pharmacology*; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006835:Hydrazones / Q000138:chemical synthesis* / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051379:Mice; D010147:Pain Measurement / Q000187:drug effects; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship
D018712:Analgesics, Non-Narcotic; D006835:Hydrazones; D011720:Pyrazoles