pyrazoles-derivatives

Pyrazole is an organic compound with the formula C3H3N2H. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. 37622-90-5, formula is C6H8N2O2, Name is Ethyl 4-pyrazolecarboxylate. Pyrazoles are a class of compounds that have the ring C3N2 with adjacent nitrogen atoms.Notable drugs containing a pyrazole ring are celecoxib (celebrex) and the anabolic steroid stanozolol. Reference of 37622-90-5.

Huang, He;Lambert, Tristan H. research published 《 Electrophotocatalytic S_NAr Reactions of Unactivated Aryl Fluorides at Ambient Temperature and Without Base》, the research content is summarized as follows. The electrophotocatalytic S_NAr reaction of unactivated aryl fluorides at ambient temperature without strong base is demonstrated.

Reference of 37622-90-5, Ethyl 4-pyrazolecarboxylate, also known as Ethyl pyrazole-4-carboxylate, is a useful research compound. Its molecular formula is C6H8N2O2 and its molecular weight is 140.14 g/mol. The purity is usually 95%.

Ethyl pyrazole-4-carboxylate is a low yield, transition metal salt that is used in the synthesis of pyrazoles. It can be synthesized by the reaction of sodium ethoxide with ethyl chloroformate and a Grignard reagent. Sodium ethoxide is added to a suspension of sodium chloride and dried ethyl chloroformate, followed by addition of magnesium turnings. The mixture is refluxed for one hour, cooled, and filtered to give crystals. Ethyl pyrazole-4-carboxylate is used in the preparation of ethyl esters from aliphatic alcohols by reacting with boron trichloride or phosphorus pentachloride. It participates in certain chemical reactions as a byproduct and can damage equipment during chemical reactions. The yield of this compound can be increased by using an excess amount of Grignard reagent or adding hexamethylenetetramine to the reaction mixture, 37622-90-5.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns. 37622-90-5, formula is C6H8N2O2, Name is Ethyl 4-pyrazolecarboxylate. 1-Methyl-5-(trifluoromethyl)pyrazole underwent deprotonation and subsequent carboxylation mainly or exclusively at either the 4-position of the heterocycle or at the nitrogen-attached methyl group. Computed Properties of 37622-90-5.

Huang, He;Strater, Zack M.;Rauch, Michael;Shee, James;Sisto, Thomas J.;Nuckolls, Colin;Lambert, Tristan H. research published 《 Electrophotocatalysis with a trisaminocyclopropenium radical dication》, the research content is summarized as follows. Visible-light photocatalysis and electrocatalysis are two powerful strategies for the promotion of chem. reactions. Here, these two modalities are combined in an electrophotocatalytic oxidation platform. This chem. employs a trisaminocyclopropenium (TAC) ion catalyst, which is electrochem. oxidized to form a cyclopropenium radical dication intermediate. The radical dication undergoes photoexcitation with visible light to produce an excited-state species with oxidizing power (3.33 V vs. SCE) sufficient to oxidize benzene and halogenated benzenes via single-electron transfer (SET), resulting in C-H/N-H coupling with azoles. A rationale for the strongly oxidizing behavior of the photoexcited species is provided, while the stability of the catalyst is rationalized by a particular conformation of the cis-2,6-dimethylpiperidine moieties.

Computed Properties of 37622-90-5, Ethyl 4-pyrazolecarboxylate, also known as Ethyl pyrazole-4-carboxylate, is a useful research compound. Its molecular formula is C6H8N2O2 and its molecular weight is 140.14 g/mol. The purity is usually 95%.

Ethyl pyrazole-4-carboxylate is a low yield, transition metal salt that is used in the synthesis of pyrazoles. It can be synthesized by the reaction of sodium ethoxide with ethyl chloroformate and a Grignard reagent. Sodium ethoxide is added to a suspension of sodium chloride and dried ethyl chloroformate, followed by addition of magnesium turnings. The mixture is refluxed for one hour, cooled, and filtered to give crystals. Ethyl pyrazole-4-carboxylate is used in the preparation of ethyl esters from aliphatic alcohols by reacting with boron trichloride or phosphorus pentachloride. It participates in certain chemical reactions as a byproduct and can damage equipment during chemical reactions. The yield of this compound can be increased by using an excess amount of Grignard reagent or adding hexamethylenetetramine to the reaction mixture, 37622-90-5.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. 761446-44-0, formula is C10H17BN2O2, Name is 1-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 °C).Pyrazole used as a ligand to prepare organometallic compounds. Recommanded Product: 1-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole.

Huang, Chunhui;Fischer, Christian;Machacek, Michelle R.;Bogen, Stephane;Biftu, Tesfaye;Huang, Xianhai;Reutershan, Michael H.;Otte, Ryan;Hong, Qingmei;Wu, Zhicai;Yu, Yang;Park, Min;Chen, Lei;Biju, Purakkattle;Knemeyer, Ian;Lu, Ping;Kochansky, Christopher J.;Hicks, Michael Brendan;Liu, Yong;Helmy, Roy;Fradera, Xavier;Donofrio, Anthony;Close, Josh;Maddess, Matthew L.;White, Catherine;Sloman, David L.;Sciammetta, Nunzio;Lu, Jun;Gibeau, Craig;Simov, Vladimir;Zhang, Hongjun;Fuller, Peter;Witter, David research published 《 Diminishing GSH-Adduct Formation of Tricyclic Diazepine-based Mutant IDH1 Inhibitors》, the research content is summarized as follows. Efforts to reduce the electron-rich nature of the core were described. Ultimately, a strategy focused on core modifications to block metabolic hot spots coupled with substitution pattern changes (C8 N → C linked) led to the identification of new tricyclic analogs such as I (R¹ = 1-aza-4-oxa[2.2.2]bicyclooctyl; R² = trans-4-isopropoxycyclohexyl) with minimal GSH-adduct formation across species while maintaining an overall balanced profile.

Recommanded Product: 1-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole, 1-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole is a useful research compound. Its molecular formula is C10H17BN2O2 and its molecular weight is 208.07 g/mol. The purity is usually 95%., 761446-44-0.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazole is an organic compound with the formula C3H3N2H. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. 269410-08-4, formula is C9H15BN2O2, Name is 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole. Pyrazoles are a class of compounds that have the ring C3N2 with adjacent nitrogen atoms.Notable drugs containing a pyrazole ring are celecoxib (celebrex) and the anabolic steroid stanozolol. Recommanded Product: 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole.

Hua, Yi;Fang, Xiaobao;Xing, Guomeng;Xu, Yuan;Liang, Li;Deng, Chenglong;Dai, Xiaowen;Liu, Haichun;Lu, Tao;Zhang, Yanmin;Chen, Yadong research published 《 Effective reaction-based de novo strategy for kinase targets: A case study on MERTK inhibitors》, the research content is summarized as follows. Reaction-based de novo design is the computational generation of novel mol. structures by linking building blocks using reaction vectors derived from chem. knowledge. In this work, we first adopted a recurrent neural network (RNN) model to generate three groups of building blocks with different functional groups and then constructed an in silico target-focused combinatorial library based on chem. reaction rules. Mer tyrosine kinase (MERTK) was used as a study case. Combined with a scaffold enrichment anal., 15 novel MERTK inhibitors covering four scaffolds were achieved. Among them, compound 5a obtained an IC₅₀ value of 53.4 nM against MERTK without any further optimization. The efficiency of hit identification could be significantly improved by shrinking the compound library with the fragment iterative optimization strategy and enriching the dominant scaffold in the hinge region. We hope that this strategy can provide new insights for accelerating the drug discovery process.

Recommanded Product: 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole, also known as 4-Pyrazoleboronic acid pinacol ester , is a useful research compound. Its molecular formula is C9H15BN2O2 and its molecular weight is 194.04 g/mol. The purity is usually 95%.

4-Pyrazoleboronic acid pinacol ester is a useful reagent for Suzuki-Miyaura cross-couplings as well as Ruthenium-catalyzed asymmetric hydrogenation. 4-Pyrazoleboronic acid pinacol ester is also a useful reagent for preparing VEGF, Aurora, RHO (ROCK), Janus Kinase 2, c-MET, ALK, S-nitrsoflutathione reductase, CDC7, Acetyl-CoA carboxylase inhibitors.

4-Pyrazoleboronic acid pinacol ester is used in the preparation of Rho kinase (ROCK) inhibitors as wella s other biologically active compounds.

4-Pyrazoleboronic acid pinacol ester is an organic compound that is the product of a bifunctional coupling reaction between 4-pyrazolecarboxylic acid and pinacol. It has been shown to inhibit protein S6 kinase, which is involved in the regulation of cell growth and proliferation. This compound has also been shown to be effective against cancer cells, including those that are resistant to conventional chemotherapeutic drugs. 4-Pyrazoleboronic acid pinacol ester may also be used as a precursor for other compounds with pharmaceutical activity., 269410-08-4.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazoles are synthesized by the reaction of α,β-unsaturated aldehydes with hydrazine and subsequent dehydrogenation. 269410-08-4, formula is C9H15BN2O2, Name is 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole. Substituted pyrazoles are prepared by condensation of 1,3-diketones with hydrazine (Knorr-type reactions). For example, acetylacetone and hydrazine gives 3,5-dimethylpyrazole. Safety of 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole.

Hu, Carol H.;Neissel Valente, Meriah W.;Halpern, O. Scott;Jusuf, Sutjano;Khan, Javed A.;Locke, Gregory A.;Duke, Gerald J.;Liu, Xiaoqin;Duclos, Franck J.;Wexler, Ruth R.;Kick, Ellen K.;Smallheer, Joanne M. research published 《 Small molecule and macrocyclic pyrazole derived inhibitors of myeloperoxidase (MPO)》, the research content is summarized as follows. Myeloperoxidase (MPO), a critical enzyme in antimicrobial host-defense, has been implicated in chronic inflammatory diseases such as coronary artery disease. The design and evaluation of MPO inhibitors for the treatment of cardiovascular disease are reported herein. Starting with the crystal structure of a triazolopyridine-MPO complex, novel inhibitors were designed incorporating a substituted pyrazole, which allowed for substituents to interact with hydrophobic and hydrophilic patches in the active site. SAR exploration of the substituted pyrazoles led to piperidinylbenzyl-substituted triazolopyridine, which inhibited HOCl production from activated neutrophils with an IC₅₀ value of 2.4μM and was selective for MPO over thyroid peroxidase (TPO). Optimization of alkylation chem. on the pyrazole nitrogen facilitated the preparation of many analogs, including macrocycles designed to bridge two hydrophobic regions of the active site. Multiple macrocyclization strategies were pursued to prepare analogs that optimally bound to the active site, leading to potent macrocyclic MPO inhibitors with TPO selectivity, such as I.

Safety of 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole, also known as 4-Pyrazoleboronic acid pinacol ester , is a useful research compound. Its molecular formula is C9H15BN2O2 and its molecular weight is 194.04 g/mol. The purity is usually 95%.

4-Pyrazoleboronic acid pinacol ester is a useful reagent for Suzuki-Miyaura cross-couplings as well as Ruthenium-catalyzed asymmetric hydrogenation. 4-Pyrazoleboronic acid pinacol ester is also a useful reagent for preparing VEGF, Aurora, RHO (ROCK), Janus Kinase 2, c-MET, ALK, S-nitrsoflutathione reductase, CDC7, Acetyl-CoA carboxylase inhibitors.

4-Pyrazoleboronic acid pinacol ester is used in the preparation of Rho kinase (ROCK) inhibitors as wella s other biologically active compounds.

4-Pyrazoleboronic acid pinacol ester is an organic compound that is the product of a bifunctional coupling reaction between 4-pyrazolecarboxylic acid and pinacol. It has been shown to inhibit protein S6 kinase, which is involved in the regulation of cell growth and proliferation. This compound has also been shown to be effective against cancer cells, including those that are resistant to conventional chemotherapeutic drugs. 4-Pyrazoleboronic acid pinacol ester may also be used as a precursor for other compounds with pharmaceutical activity., 269410-08-4.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazoles and pyrimidines have diverse biological and pharmacological activities. 37622-90-5, formula is C6H8N2O2, Name is Ethyl 4-pyrazolecarboxylate. There are a number of antimicrobial compounds containing pyrazole moiety as the core unit. Application of C6H8N2O2.

Hou, Zhong-Wei;Li, Laiqiang;Wang, Lei research published 《 Organocatalytic electrochemical amination of benzylic C-H bonds》, the research content is summarized as follows. An organocatalytic site-selective electrochem. method for the benzylic C-H amination reactions of alkylarenes with azoles through hydrogen evolution was developed. The protocol proceeds in an undivided cell under mild conditions and employs 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as a redox catalyst to generate carbocations, which obviates the need for transition-metal reagents or sacrificial chem. oxidants.

37622-90-5, Ethyl 4-pyrazolecarboxylate, also known as Ethyl pyrazole-4-carboxylate, is a useful research compound. Its molecular formula is C6H8N2O2 and its molecular weight is 140.14 g/mol. The purity is usually 95%.

Ethyl pyrazole-4-carboxylate is a low yield, transition metal salt that is used in the synthesis of pyrazoles. It can be synthesized by the reaction of sodium ethoxide with ethyl chloroformate and a Grignard reagent. Sodium ethoxide is added to a suspension of sodium chloride and dried ethyl chloroformate, followed by addition of magnesium turnings. The mixture is refluxed for one hour, cooled, and filtered to give crystals. Ethyl pyrazole-4-carboxylate is used in the preparation of ethyl esters from aliphatic alcohols by reacting with boron trichloride or phosphorus pentachloride. It participates in certain chemical reactions as a byproduct and can damage equipment during chemical reactions. The yield of this compound can be increased by using an excess amount of Grignard reagent or adding hexamethylenetetramine to the reaction mixture, Application of C6H8N2O2

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazole is an organic compound with the formula C3H3N2H. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. 2075-46-9, formula is C3H3N3O2, Name is 4-Nitro-1H-pyrazole. Pyrazoles are a class of compounds that have the ring C3N2 with adjacent nitrogen atoms.Notable drugs containing a pyrazole ring are celecoxib (celebrex) and the anabolic steroid stanozolol. Application of C3H3N3O2.

Hou, Zhong-Wei;Li, Laiqiang;Wang, Lei research published 《 Organocatalytic electrochemical amination of benzylic C-H bonds》, the research content is summarized as follows. An organocatalytic site-selective electrochem. method for the benzylic C-H amination reactions of alkylarenes with azoles through hydrogen evolution was developed. The protocol proceeds in an undivided cell under mild conditions and employs 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as a redox catalyst to generate carbocations, which obviates the need for transition-metal reagents or sacrificial chem. oxidants.

Application of C3H3N3O2, 4-Nitro-1H-pyrazole, also known as 4-Nitropyrazole, is a useful research compound. Its molecular formula is C3H3N3O2 and its molecular weight is 113.08 g/mol. The purity is usually 95%.

4-Nitropyrazole, is a building block for the synthesis of various pharmaceutical compounds, including inhibitors, and therapeutic agents. It can be used for the synthesis of highly selective, brain-penetrant aminopyrazole LRRK2 Inhibitor, as a potentially viable treatment for Parkinson’s disease., 2075-46-9.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazole is an organic compound with the formula C3H3N2H. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. 2075-46-9, formula is C3H3N3O2, Name is 4-Nitro-1H-pyrazole. Pyrazoles are a class of compounds that have the ring C3N2 with adjacent nitrogen atoms.Notable drugs containing a pyrazole ring are celecoxib (celebrex) and the anabolic steroid stanozolol. Reference of 2075-46-9.

Hou, Zhong-Wei;Xu, Hai-Chao research published 《 Electrophotocatalytic C-H Azolation of Arenes》, the research content is summarized as follows. An electrophotocatalytic method was developed for the dehydrogenative cross coupling of arenes with azoles employing a bicatalytic system consisting of acridinium dye and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO). The reactions were conducted in a simple undivided cell with visible-light irradiation and requires no external chem. oxidant.

Reference of 2075-46-9, 4-Nitro-1H-pyrazole, also known as 4-Nitropyrazole, is a useful research compound. Its molecular formula is C3H3N3O2 and its molecular weight is 113.08 g/mol. The purity is usually 95%.

4-Nitropyrazole, is a building block for the synthesis of various pharmaceutical compounds, including inhibitors, and therapeutic agents. It can be used for the synthesis of highly selective, brain-penetrant aminopyrazole LRRK2 Inhibitor, as a potentially viable treatment for Parkinson’s disease., 2075-46-9.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazoles and pyrimidines have diverse biological and pharmacological activities. 269410-08-4, formula is C9H15BN2O2, Name is 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole. There are a number of antimicrobial compounds containing pyrazole moiety as the core unit. Related Products of 269410-08-4.

Hou, Shaohua;Yang, Xiping;Tong, Yu;Yang, Yuejing;Chen, Quanwei;Wan, Boheng;Wei, Ran;Wang, Yuchen;Zhang, Yanmin;Kong, Bo;Huang, Jianhang;Chen, Yadong;Lu, Tao;Hu, Qinghua;Du, Ding research published 《 Structure-based discovery of 1H-indole-2-carboxamide derivatives as potent ASK1 inhibitors for potential treatment of ulcerative colitis》, the research content is summarized as follows. Apoptosis signal-regulating kinase 1 (ASK1), a member of the mitogen-activated protein kinase (MAPK) family, is implicated in many human diseases. Here, we describe the structural optimization of a hit compound and conduct further structure-activity relationship (SAR) studies that result in the development of the indole-2-carboxamide I. I displays potent anti-ASK1 kinase activity and stronger inhibitory effect on ASK1 in AP1-HEK293 cells than previously described ASK1 inhibitor GS-4997. Besides improved in vitro activity, I also exhibits an appropriate in vivo PK profile. In a dextran sulfate sodium (DSS)-induced mouse model of ulcerative colitis (UC), I shows significant anti-UC efficacy and markedly attenuates DSS-induced body weight loss, colonic shortening, elevation in disease activity index (DAI) and inflammatory cell infiltration in colon tissues. Mechanistically, I represses the phosphorylation of ASK1-p38/JNK signaling pathways and suppresses the overexpression of inflammatory cytokines. Together, these findings suggest that ASK1 inhibitors can potentially be used as a therapeutic strategy for UC.

269410-08-4, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole, also known as 4-Pyrazoleboronic acid pinacol ester , is a useful research compound. Its molecular formula is C9H15BN2O2 and its molecular weight is 194.04 g/mol. The purity is usually 95%.

4-Pyrazoleboronic acid pinacol ester is a useful reagent for Suzuki-Miyaura cross-couplings as well as Ruthenium-catalyzed asymmetric hydrogenation. 4-Pyrazoleboronic acid pinacol ester is also a useful reagent for preparing VEGF, Aurora, RHO (ROCK), Janus Kinase 2, c-MET, ALK, S-nitrsoflutathione reductase, CDC7, Acetyl-CoA carboxylase inhibitors.

4-Pyrazoleboronic acid pinacol ester is used in the preparation of Rho kinase (ROCK) inhibitors as wella s other biologically active compounds.

4-Pyrazoleboronic acid pinacol ester is an organic compound that is the product of a bifunctional coupling reaction between 4-pyrazolecarboxylic acid and pinacol. It has been shown to inhibit protein S6 kinase, which is involved in the regulation of cell growth and proliferation. This compound has also been shown to be effective against cancer cells, including those that are resistant to conventional chemotherapeutic drugs. 4-Pyrazoleboronic acid pinacol ester may also be used as a precursor for other compounds with pharmaceutical activity., Related Products of 269410-08-4

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazole is an organic compound with the formula C3H3N2H. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. 37622-90-5, formula is C6H8N2O2, Name is Ethyl 4-pyrazolecarboxylate. Pyrazoles are a class of compounds that have the ring C3N2 with adjacent nitrogen atoms.Notable drugs containing a pyrazole ring are celecoxib (celebrex) and the anabolic steroid stanozolol. Reference of 37622-90-5.

Holmberg-Douglas, Natalie;Choi, Younggi;Aquila, Brian;Huynh, Hoan;Nicewicz, David A. research published 《 β-Functionalization of Saturated Aza-Heterocycles Enabled by Organic Photoredox Catalysis》, the research content is summarized as follows. The β-functionalization of saturated aza-heterocycles, e.g., I, enabled by a two-step organic photoredox catalysis approach was demonstrated. Initially, a photoredox-catalyzed copper-mediated dehydrogenation of saturated aza-heterocycles, e.g., II, produces ene-carbamates, e.g., III. This is followed by an anti-Markovnikov hydrofunctionalization of the ene-carbamates, e.g., III, with a range of heteroatom-containing nucleophiles furnishing an array of C-C, C-O and C-N aza-heterocycles, e.g., I, at the β-position.

Reference of 37622-90-5, Ethyl 4-pyrazolecarboxylate, also known as Ethyl pyrazole-4-carboxylate, is a useful research compound. Its molecular formula is C6H8N2O2 and its molecular weight is 140.14 g/mol. The purity is usually 95%.

Ethyl pyrazole-4-carboxylate is a low yield, transition metal salt that is used in the synthesis of pyrazoles. It can be synthesized by the reaction of sodium ethoxide with ethyl chloroformate and a Grignard reagent. Sodium ethoxide is added to a suspension of sodium chloride and dried ethyl chloroformate, followed by addition of magnesium turnings. The mixture is refluxed for one hour, cooled, and filtered to give crystals. Ethyl pyrazole-4-carboxylate is used in the preparation of ethyl esters from aliphatic alcohols by reacting with boron trichloride or phosphorus pentachloride. It participates in certain chemical reactions as a byproduct and can damage equipment during chemical reactions. The yield of this compound can be increased by using an excess amount of Grignard reagent or adding hexamethylenetetramine to the reaction mixture, 37622-90-5.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics