94209-24-2Relevant academic research and scientific papers
La(OTf)3-catalysed one-pot synthesis of pyrazole tethered imidazo[1,2-: A] azine derivatives and evaluation of their light emitting properties
Sharma, Shubham,Paul, Avijit Kumar,Singh, Virender
supporting information, p. 684 - 694 (2020/01/31)
A facile and efficient protocol has been unfolded towards the diversity-oriented synthesis of highly fluorescent pyrazole C-3(5) tethered imidazo[1,2-a]azines via an La(OTf)3 catalysed one-pot multicomponent assembly of pyrazole carbaldehydes, 2-aminoazines and isonitriles. This present protocol offers several advantages such as multiple bond formation in a single step, low catalyst loading, short reaction time, appreciable atom economy, good functional group tolerance, scalability and easy to perform reaction conditions. The optical properties of pyrazolyl imidazo[1,2-a]azines were also studied, and they exhibited an excellent fluorescence quantum yield (ΦF up to 83%).
Application of Photoclick Chemistry for the Synthesis of Pyrazoles via 1,3-Dipolar Cycloaddition between Alkynes and Nitrilimines Generated In Situ
Remy, Richard,Bochet, Christian G.
, p. 316 - 328 (2018/01/27)
The photochemical extrusion of gaseous nitrogen from 2,5-disubstituted tetrazoles to generate reactive nitrilimines in situ represents an efficient and attractive way to form dipoles that can be used to provide useful chemicals via 1,3-dipolar cycloadditions. The concept of “photoclick chemistry” already inspired numerous researchers, who exploited photochemical processes involving alkenes for the synthesis of adducts or the functionalization of biocompatible materials. The approach requires bioorthogonality, ease of access to the starting materials and operational simplicity. We report herein our investigations toward a photoclick reaction involving 2,5-disubstituted tetrazoles and alkynes as the dipolarophile for the synthesis of pyrazole derivatives. In addition to the numerous reports recently published on the synthesis of pyrazoles, we wish to add to the list a photochemical procedure that represents a mild and atom-economical alternative. Moreover, considering that such nitrilimines precursors can be accessed in one step from inexpensive and abundant starting materials and given the commercial availability of a broad spectrum of alkynes, we examined the scope of the photoclick reaction with respect to reactive partners, enabling the synthesis of a library of useful heteroaromatics.
New synthetic access to 3-fluoroalkyl-5-pyrazolecarboxylates and carboxylic acids
Herrera, Alberto Gómez,Schmitt, Etienne,Panossian, Armen,Vors, Jean-Pierre,Pazenok, Sergii,Leroux, Frédéric R.
, p. 17 - 23 (2018/08/10)
A novel process for preparing 3-fluoroalkyl-5-pyrazolecarboxylates and carboxylic acids is hereby presented. Easily accesible α-fluorinated ketimines were condensed with oxalyl monochloride derivatives, and the obtained vinamides underwent acid-catalyzed cyclization with substituted hydrazines. This highly efficient protocol can also be used for non-fluorinated C-3 and C-5 substituents.
Discovery of 1,5-Diphenylpyrazole-3-Carboxamide Derivatives as Potent, Reversible, and Selective Monoacylglycerol Lipase (MAGL) Inhibitors
Aghazadeh Tabrizi, Mojgan,Baraldi, Pier Giovanni,Baraldi, Stefania,Ruggiero, Emanuela,De Stefano, Lucia,Rizzolio, Flavio,Di Cesare Mannelli, Lorenzo,Ghelardini, Carla,Chicca, Andrea,Lapillo, Margherita,Gertsch, Jürg,Manera, Clementina,Macchia, Marco,Martinelli, Adriano,Granchi, Carlotta,Minutolo, Filippo,Tuccinardi, Tiziano
, p. 1340 - 1354 (2018/02/17)
Monoacylglycerol lipase (MAGL) is a serine hydrolase that plays an important role in the degradation of the endocannabinoid neurotransmitter 2-arachidonoylglycerol, which is implicated in many physiological processes. Beyond the possible utilization of MA
One-Pot Synthesis of Highly Substituted 1H-Pyrazole-5-carboxylates from 4-Aryl-2,4-diketoesters and Arylhydrazines
Zhai, Jiao-Jiao,Gu, Chun-Hui,Guo, Ying,Liao, Dao-Hua,Zhu, Dun-Ru,Ji, Ya-Fei
, p. 840 - 848 (2016/05/19)
A one-pot synthesis of highly substituted 1H-pyrazole-5-carboxylates 1 has been developed starting from easily available 4-aryl-2,4-diketoesters 2 and arylhydrazine hydrochlorides 3. More active 2-carbonyl group of 2 was blocked with methoxyamine hydrochloride to give 2-methoxy imine intermediates, which were then subjected to condensation cyclization with 3 in situ to provide the desired products 1. In addition, the geometrical configuration of 1aa was unambiguously confirmed by single crystal X-ray crystallography.
HISTONE DEACETYLASE INHIBITORS AND COMPOSITIONS AND METHODS OF USE THEREOF
-
Paragraph 00169, (2014/10/15)
Provided are certain histone deacetylase (HDAC) inhibitors of Formula I, compositions thereof, and methods of their use.
Functionalized heterocyclic scaffolds derived from Morita-Baylis-Hillman Acetates
Zhu, Huajian,Shao, Nana,Chen, Tong,Zou, Hongbin
supporting information, p. 7738 - 7740 (2013/09/02)
Five series of heterocycles with extraordinary structural diversity have been regiospecifically synthesized from the same Morita-Baylis-Hillman Acetates (MBHAs). All four potential electrophilic sites (α, β, γ, δ) of MBHAs are proved to be reactive.
Synthesis of bromodifluoromethyl substituted pyrazoles and isoxazoles
Yang, Xueyan,Shui, Shengxia,Chen, Xi,He, Hai'ou,Wu, Fanhong
experimental part, p. 426 - 432 (2010/04/23)
Bromodifluoromethyl substituted β-diketone 3a-3d, prepared from corresponding ketones and ethyl bromodifluoroactate in the presence of sodium methoxide, reacted with aryl hydrazine derivatives affording bromodifluoromethyl substituted pyrazoles in high re
New pyrazolium-carboxylates as structural analogues of the pseudo-cross-conjugated betainic alkaloid nigellicine
Schmidt, Andreas,Habeck, Tobias,Kindermann, Markus Karl,Nieger, Martin
, p. 5977 - 5982 (2007/10/03)
Pyrazolium-3-carboxylates were examined as relatives of the betainic alkaloid Nigellicine and as new examples of the sparsely populated class 16 of heterocyclic pseudo-cross-conjugated mesomeric betaines (PCCMB). The title compounds were prepared in a 4-step procedure starting from β-diketo compounds 8 which were cyclized with substituted hydrazines. The resulting isomeric pyrazole esters 9 and 10 were separated and subsequently quaternized with dimethyl sulfate in the presence of nitrobenzene to pyrazolium esters 11 and 12. Saponification was best accomplished in diluted sulfuric acid, which resulted in the formation of the pseudo-cross-conjugated mesomeric betaines 13 and 14 in one step. Protonation to the corresponding carboxylic acids required the treatment of the betaines with tetrafluoroboric acid in dichloromethane. The effect of negative solvatochromism proves the charge separation in the ground state of the molecules. X-ray crystallographic analyses, semiempirical calculations, and ESI mass spectrometric measurements were performed to gain knowledge about the phenomenon of pseudo-cross-conjugation.
Haloacetylated enol ethers. 11 [16]. Synthesis of 1-methyl- and 1- phenyl pyrazole-3(5)-ethyl esters. A one-pot procedure
Martins, Marcos A. P.,Freitag, Rogerio A.,Da Rosa, Adriano,Flores, Alex F. C.,Zanatta, Nilo,Bonacorso, Helio G.
, p. 217 - 220 (2007/10/03)
A one-pot synthesis of 1-methyl- and 1-phenylpyrazole-3(5)-ethyl esters 2,3a-e by the cyclocondensation of β-alkoxyvinyl trichloromethyl ketones 1a- e with methyl and phenyl hydrazine hydrochloride under mild conditions, is reported. A study using compounds la-e with different substituents proved that these are versatile building blocks for the synthesis of pyrazole derivatives, having a 3(5)-ethoxycarbonyl substituent in good yields (60- 89%). The hydrazine and β-alkoxyvinyl trichloromethyl ketone substituent effects on the reaction regiochemistry on the formation of the 1,3- and 1,5- isomer were observed.
