191419-22-4Relevant articles and documents
Novel 5-functionalized-pyrazoles: Synthesis, characterization and pharmacological screening
Doddaramappa, Shridevi D.,Lokanatha Rai,Srikantamurthy, Ningaiah,Chandra,Chethan, Javarasetty
, p. 3671 - 3675 (2015)
In the present study a series of O-substituted pyrazoles 7(a-f) and N-substituted pyrazoles 9(a-f) were synthesized via phase-transfer catalyzed reaction of ethyl 5-(bromomethyl)-1,3-diphenyl-1H-pyrazole-4-carboxylate 5 with various oxygen and nitrogen containing compounds in presence of tetrabutylammonium bromide (TBAB) in THF. The compound 5 was obtained by the efficient bromination with N-bromosuccinimide (NBS) in presence of a catalytic amount of azoiso-bis-butyro nitrile (AIBN) in refluxing CCl4. The synthesized compounds were evaluated for their in vitro antimicrobial and antidiabetic activity and were compared with standard drugs. Among the synthesized compounds, compound 9b emerged as an excellent antimicrobial and antidiabetic agent. Newly synthesized compounds were characterized by analytical and spectral (IR, 1H NMR, 13C NMR and LC-MS) methods.
Reaction of 4-Hydroxy-5-oximino-3-thiophenecarboxylates with Hydrazines. Formation of Pyrazolylthiohydroxamic Acids
Robey,Alt,Van Meter
, p. 413 - 428 (2007/10/03)
The reactions of 4-hydroxy-5-oximino-3-thiophenecarboxylates with hydrazine and substituted hydrazines have been investigated. The products of the reactions have been shown to be pyrazole-3- or 5-thiohydroxamic acids rather than the hydrazones previously described by Benary and Silberstrom. Two alternate mechanisms are proposed which account for the regiochemical outcome. The structures of the pyrazole-3- and 5-thiohydroxamic acids and corresponding nitriles have been proven by independent synthesis, comparison to known compounds, and by proton and carbon magnetic resonance and long range HETCOR experiments.
