13808-62-3Relevant articles and documents
Effective and highly stereoselective coupling with vinyldiazomethanes to form symmetrical trienes
Doyle, Michael P.,Yan, Ming
, p. 602 - 604 (2002)
Diazo coupling reactions are capable of forming E,E,E-trienes from cinnamaldehydes in good yield. An efficient methodology is reported for the production of styryldiazomethanes that are subsequently used with catalysis for coupling and for cyclopropanatio
Calcium carbide as the acetylide source: Transition-metal-free synthesis of substituted pyrazoles via [1,5]-sigmatropic rearrangements
Yu, Yue,Huang, Wei,Chen, Yang,Gao, Bingjie,Wu, Wanqing,Jiang, Huanfeng
supporting information, p. 6445 - 6449 (2018/06/08)
Under transition-metal-free conditions, calcium carbide was used as the acetylide source to react with a wide range of N-tosylhydrazones derived from aldehydes or ketones, affording various substituted pyrazoles in good yields with high regioselectivities. The transformations go through [3 + 2] cycloadditions followed by [1,5]-sigmatropic rearrangements, which are supported by deuterium-labeling experiments.
Efficient one-pot synthesis of substituted pyrazoles
Tang, Meng,Zhang, Fu-Min
, p. 1427 - 1433 (2013/02/25)
An efficient, one-pot synthesis of substituted pyrazoles from enones, hydrazides, and halides was developed. In comparison with the classical Knorr pyrazole synthesis, this methodology gave a different type of product (R 3≥R5). A range of substituted pyrazoles were prepared in good to high yields with complete regioselectivity.
A simple and efficient synthesis of pyrazoles in water
Wen, Jun,Fu, Yun,Zhang, Ruo-Yi,Zhang, Ji,Chen, Shan-Yong,Yu, Xiao-Qi
supporting information; experimental part, p. 9618 - 9621 (2011/12/14)
A simple, highly efficient, and environmentally friendly method for the synthesis of substituted 1H-pyrazoles by one-pot condensation reaction of α,β-unsaturated carbonyl compounds with tosyl hydrazide in water was developed. The reaction system exhibited tolerance with various functional groups, Aromatic moiety with both electron-rich and electron-deficient substituents could give desired products in good to excellent yields.
New synthesis of fluorinated pyrazoles
Surmont, Riccardo,Verniest, Guido,De Kimpe, Norbert
supporting information; experimental part, p. 4648 - 4651 (2010/12/19)
A new synthesis of fluorinated pyrazoles, a class of compounds with potential in medicinal chemistry, is described. The treatment of benzoylfluoroacetonitrile with hydrazine yielded the expected new 3-amino-4-fluoropyrazole, while the analogous reaction of α-cyano-α, α-difluoroketones with hydrazine in refluxing isopropanol surprisingly gave rise to 3-unsubstituted 4-fluoropyrazoles via an unprecedented mechanism. The isolation of intermediate hydrazine adducts led to a mechanistic rationale for this transformation.
NOVEL SUBSTITUTED PYRAZOLE DERIVATIVE, PROCESS FOR PRODUCING THE SAME, AND HERBICIDAL COMPOSITION CONTAINING THE SAME
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Page 27, (2010/02/08)
The invention provides substituted pyrazole compounds of the formula (1). They are novel substances synthesized from a pyrazole derivative and a haloalkyleneoxime ester derivative, and have excellent herbicidal effects. Herbicide compositions containing t
Method for producing substituted pyrazoles
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, (2008/06/13)
Pyrazole derivatives are prepared by reacting carbonyl compounds R1—C(O)—CH(R2)—CH2R3with hydrazine, its hydrate or its salts in 30 to 100% by weight sulfuric acid in the presence of catalytic amounts of iodine or of an iodine compound.
Formation and Structure of 1-Amino-4-methyl-4-(4-methyl-5-phenyl1H-pyrazol-3-ylamino)-3-phenyl-4,5-dihydro- 1H-pyrazol-5-one
Donati, Donato,Fusi, Stefania,Ponticelli, Fabio
, p. 109 - 112 (2007/10/03)
The title compound 3 was obtained during the rearrangement of isoxazol-5-yl hydrazine 1 to 1-aminopyrazolone 2 at 115°. X-ray analysis of the corresponding benzylidene derivative allowed us to achieve the structure assignment.
Novel Parham-type Cycloacylations of 1H-Pyrazole-1-alkanoic Acids
Larsen, Scott D.
, p. 1013 - 1014 (2007/10/03)
Exposure of 1H-pyrazole-1-alkanoic acids to two equivalents of n-butyllithium affords the corresponding cyclic ketones via a Parham-type cyclization process. Although yields are modest, this procedure represents a simple and direct intramolecular acylation of a non-nucleophilic pyrazole carbon.
Chain Elongation of Carbohydrates: Synthesis of Pyrazoles from Optically Active Carboxylic Acids
Klein, Ulrich,Mohrs, Klaus,Wild, Hanno,Steglich, Wolfgang
, p. 485 - 490 (2007/10/02)
By chain elongation via the C-phenylglycine method optically active carboxylic acids may be converted into 3-substituted pyrazoles in few steps with good chemical yields.Starting with peracetylated glyconic acids this technique permits an easy access to u
