One-Pot Synthesis of 3(5)-Ethoxycarbonylpyrazoles

Martins, Marcos A. P.; Freitag, Rogério Antônio; Flores, Alex F. C.; Zanatta, Nilo

doi:10.1055/s-1995-4147

Cited by 49 publications

(19 citation statements)

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“…This reaction condition promoted the cyclocondensation and the hydrolysis of the trichloromethyl group. 18,19 In addition, the treatment of 5-trichloromethylpyrazoles 8 and 10 in pyridine with an appropriate alcohol under reflux, also led to the carboxypyrazoles 11-14, in good yields (Scheme 2, Table 2). …”

Section: Resultsmentioning

confidence: 99%

Regiospecific synthesis of 1,2-bis(azolyl)ethanes

Martins¹,

Cúnico²,

Siqueira³

et al. 2005

J. Braz. Chem. Soc.

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Section: Resultsmentioning

confidence: 99%

Regiospecific synthesis of 1,2-bis(azolyl)ethanes

Martins¹,

Cúnico²,

Siqueira³

et al. 2005

J. Braz. Chem. Soc.

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“…We started our study from the cyclocondensation reaction of 5‐bromo[5,5‐dibromo]‐1,1,1‐trichloro‐4‐methoxy‐3‐penten‐2‐ones, 4c (1 mmol), with hydrazine monohydrate (1.1 mmol), by evaluating the best reaction conditions for the formation of compound 6c . The first test was performed in ethanol as solvent at 65°C for 4 h, on the basis of a work previously published by us . However, the product was not identified using these reaction conditions.…”

Section: Resultsmentioning

confidence: 99%

“…Despite extensive studies on applications of 4‐alkoxy‐1,1,1‐trihalo‐3‐alken‐2‐ones in heterocyclic chemistry , 5‐heteroalkyl substituted 4‐alkoxy‐1,1,1‐trihalo‐3‐alken‐2‐ones and their usefulness in the synthesis of heterocycles have been less explored. These compounds are highly functionalized intermediates, which may be useful for further synthetic conversions.…”

Section: Introductionmentioning

confidence: 99%

Brominated Trihalomethylenones as Versatile Precursors to 3‐Ethoxy, ‐Formyl, ‐Azidomethyl, ‐Triazolyl, and 3‐Aminomethyl Pyrazoles

Martins

Sinhorin

Frizzo

et al. 2013

Journal of Heterocyclic Chem

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5‐Bromo[5,5‐dibromo]‐1,1,1‐trihalo‐4‐methoxy‐3‐penten[hexen]‐2‐ones are explored as precursors to the synthesis of 3‐ethoxymethyl‐5‐trifluoromethyl‐1H‐pyrazoles from a cyclocondensation reaction with hydrazine monohydrate in ethanol. 3‐Ethoxymethyl‐carboxyethyl ester pyrazoles were formed as a result of a substitution reaction of bromine and chlorine by ethanol. The dibrominated precursor furnished 3‐acetal‐pyrazole that was easily hydrolyzed to formyl group. In addition, brominated precursors were used in a nucleophilic substitution reaction with sodium azide to synthesize the 3‐azidomethyl‐5‐ethoxycarbonyl‐1H‐pyrazole from the reaction with hydrazine monohydrate. These products were submitted to a cycloaddition reaction with phenyl acetylene furnishing the 3‐[4(5)‐phenyl‐1,2,3‐triazolyl]5‐ ethoxycarbonyl‐1H‐pyrazoles and to reduction conditions resulting in 3‐aminomethyl‐1H‐pyrazole‐5‐carboxyethyl ester. The products were obtained by a simple methodology and in moderate to good yields.

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“…It is important to mention that (−)-Thapsigargin itself was not obtained in a gramscale due to safety reasons, once this compound is highly toxic. The gram-scale endpoint is a highly (Martins et al 1995). -1970- 's (Brocksom et al 1974 (Figure 49), and the pioneer total synthesis of sativene and copacamphene via a radical cyclization by Bakuzis (Bakuzis et al 1976) (Figure 50), the area of synthetic methodology in Brazil has grown steadly over the last five decades.…”

Section: Examples Of Large-scale Complex Synthesesmentioning

confidence: 99%

Organic Synthesis: New Vistas in the Brazilian Landscape

Pilli

Assis

2018

An. Acad. Bras. Ciênc.

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In this overview, we present our analysis of the future of organic synthesis in Brazil, a highly innovative and strategic area of research which underpins our social and economical progress. Several different topics (automation, catalysis, green chemistry, scalability, methodological studies and total syntheses) were considered to hold promise for the future advance of chemical sciences in Brazil. In order to put it in perspective, contributions from Brazilian laboratories were selected by the citations received and importance for the field and were benchmarked against some of the most important results disclosed by authors worldwide. The picture that emerged reveals a thriving area of research, with new generations of well-trained and productive chemists engaged particularly in the areas of green chemistry and catalysis. In order to fulfill the promise of delivering more efficient and sustainable processes, an integration of the academic and industrial research agendas is to be expected. On the other hand, academic research in automation of chemical processes, a well established topic of investigation in industrial settings, has just recently began in Brazil and more academic laboratories are lining up to contribute. All these areas of research are expected to enable the future development of the almost unchartered field of scalability.

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One-Pot Synthesis of 3(5)-Ethoxycarbonylpyrazoles

Cited by 49 publications

References 0 publications

Regiospecific synthesis of 1,2-bis(azolyl)ethanes

Regiospecific synthesis of 1,2-bis(azolyl)ethanes

Brominated Trihalomethylenones as Versatile Precursors to 3‐Ethoxy, ‐Formyl, ‐Azidomethyl, ‐Triazolyl, and 3‐Aminomethyl Pyrazoles

Organic Synthesis: New Vistas in the Brazilian Landscape

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