68426-71-1Relevant academic research and scientific papers
Formyl substituent at C-4 of pyrazoles: A temporary protecting group for regioselective palladium-catalyzed direct arylation at C-5
Smari, Imen,Youssef, Chiraz,Yuan, Kedong,Beladhria, Anissa,Ben Ammar, Hamed,Ben Hassine, Bechir,Doucet, Henri
, p. 1778 - 1786 (2014/03/21)
Pyrazoles with an aldehyde function at C-4 underwent a palladium-catalyzed direct arylation reaction to provide a regioselective approach to 5-aryl-substituted pyrazoles. The reaction proceeds in moderate to high yields with a variety of aryl bromides in the presence of 2 mol-% of Pd(OAc) 2 as the catalyst. The use of an aldehyde function at C-4 of the pyrazoles presents several advantages: (1) 4-formylpyrazoles are easily prepared from hydrazine derivatives, ketones, and N,N-dimethylformamide (DMF), (2) the control of the regioselectivity of the arylation at C-5 of the pyrazole, (3) the aldehyde substituent can easily be transformed into a wide variety of other substituents, and (4) the formyl group can be considered a temporary protecting group, as it can be removed by a straightforward reaction. Copyright
Formyl Substituent at C-4 of Pyrazoles: A Temporary Protecting Group for Regioselective Palladium-Catalyzed Direct Arylation at C-5
Smari, Imen,Youssef, Chiraz,Yuan, Kedong,Beladhria, Anissa,Ben Ammar, Hamed,Ben Hassine, Bechir,Doucet, Henri
, p. 1778 - 1786 (2015/10/05)
Pyrazoles with an aldehyde function at C-4 underwent a palladium-catalyzed direct arylation reaction to provide a regioselective approach to 5-aryl-substituted pyrazoles. The reaction proceeds in moderate to high yields with a variety of aryl bromides in the presence of 2 mol-% of Pd(OAc)2 as the catalyst. The use of an aldehyde function at C-4 of the pyrazoles presents several advantages: (1) 4-formylpyrazoles are easily prepared from hydrazine derivatives, ketones, and N,N-dimethylformamide (DMF), (2) the control of the regioselectivity of the arylation at C-5 of the pyrazole, (3) the aldehyde substituent can easily be transformed into a wide variety of other substituents, and (4) the formyl group can be considered a temporary protecting group, as it can be removed by a straightforward reaction.
1-AZADIENES AS A SYNTHON FOR HETEROCYCLIC SYNTHESIS
Ohshiro, Yoshiki,Komatsu, Mitsuo,Uesaka, Masatoshi,Agawa, Toshio
, p. 549 - 559 (2007/10/02)
1-Azabutadienes 1 were found to be a good building block for three- to five-membered heterocycles having a functional group.Oxidation of 1 with mCPBA afforded 3-alkenyloxaziridines 2.Cycloaddition of 1 with ketenes gave the 4-alkenylazetidinones 6.Addition of a nitrile imine occured across the C=N bond to give the 3-alkenyltriazoline 8, while that of a nitrile ylide occurred on the C=C bond to give the 3-formylpyrrole 14 formed by hydrolysis of the C=N bond.
Pyrazol-4-acetic acid compounds
-
, (2008/06/13)
Pyrazol-4-acetic acid compounds, such as substituted pyrazol-4-acetic acid, its esters, amides, nitriles and their pharamaceutically acceptable salts and method for the preparation of these compounds are disclosed. The novel compounds are useful analgesics, anti-inflammatory, and antipyretics.
