Preparation and Chemistry of 3/5-Halogenopyrazoles

Abstract

3924 2. Electrophilic Halogenations 3925 2.1. Electrophilic Halogenation of Pyrazoles 3925 2.2. Halogenation of Pyrazole Anions 3929 3. Preparations from 3/5-Hydroxy-or 3/5-Aminopyrazoles 3930 3.1. Dehydroxyhalogenation of 3/5-Hydroxypyrazoles 3930 3.2. Halogenodediazoniation of 3/5-Aminopyrazoles 3934 4. Rearrangements, Cycloadditions, and Condensations 3936 4.1. Rearrangement of Pyrazole N-Oxides 3936 4.2. Cycloadditions 3937 4.3. Condensations 3938 5. Modifications of 3/5-Halogenopyrazoles 3940 6. Miscellaneous 3943 7. Chemistry of Halogenopyrazoles 3944 7.1. Chemistry of 4-Halogenoyrazoles 3944 7.1. Chemistry of 3/5-Halopyrazoles and Activated Esters of Hydroxypyrazoles 3947 7.3. CH Activation of Pyrazoles 3949 8. Conclusion 3951 Author Information 3951 Corresponding Author 3951 Notes 3951 Biography 3951 Acknowledgments 3951 References 3951

Novel directed synthesis of functionalized pyrazole derivatives via regioselective solvent-free thiylation of 3-alkenylpyrazoles with arenethiols

“…Pyrazole and its derivatives attract the attention of the chemical community mainly on account of the wide spectrum of their pharmacological activities, [1][2][3][4][5][6] including antibacterial, 7 antidepressant, 8 antiinflammatory, 9 antitumor, 10 etc. They are widely used as agrochemicals.…”

“…24,25 They are also applied in the design of complexes with unusual magnetic properties. 26,27 In the search for novel pyazoles as building blocks for the synthesis of biologically active and technologically useful substances, [1][2][3][4][5][6] the development of new methods for the preparation of functionalized pyrazoles and the synthesis of new pyrazole derivatives present an urgent challenge.…”

“…[1][2][3][4][5][6][28][29][30][31][32][33][34][35][36][37][38][39] The chemical transformations of alkenylpyrazoles are still poorly understood. It is known that N-alkenyl-and some 4-alkenylpyrazoles can participate in polymerization, 21,29 complex formation, 30,31 thiylation, 32 and cycloaddition.…”

Molecular and Solid State Structure of the Doubly-Substituted B-Diketone 3,3'-Bis(ferrocenylmethyl)pentane-2,4-Dione#

“…β-Diketones are an important class of organic compounds frequently encountered in synthetic chemistry, 1,2 where in addition to their established role in the synthesis of various heterocyclic derivatives which have been widely studied and reviewed, [3][4][5][6] they have been used as ligands for the coordination of transition metals. 7,8 On the other hand, β-diketones are attractive building blocks for the construction of polydentate Schiff bases, and both the parent derivative 2,4-pentanedione (CH 3 COCH 2 COCH 3 ), [9][10][11][12] and its organometallic counterpart ferrocenoylacetone (FcCOCH 2 COCH 3 , 13 Fc = (h 5 -C 5 H 5 )Fe(h 5 -C 5 H 4 )) have been widely employed to prepare tridentate Schiff base complexes, also called half-units, upon mono-condensation with primary diamines.…”

Synthesis and investigation of isomeric mono- and dinitro derivatives of 3-methyl-4-(pyrazol-3-yl)furazan

“…This study was aimed at the method development for the synthesis of nitropyrazoles bearing a furazanyl moiety at position 3 (5). 3(5)-Furazanylpyrazoles have been hitherto unknown, while some examples of 1-47,48 and 4-(furazanyl)-pyrazoles 49 have been described in the literature.…”