64847-20-7Relevant academic research and scientific papers
Decarboxylative Fluorination of Electron-Rich Heteroaromatic Carboxylic Acids with Selectfluor
Yuan, Xi,Yao, Jian-Fei,Tang, Zhen-Yu
, p. 1410 - 1413 (2017/03/23)
A transition-metal-free decarboxylative fluorination of electron-rich five-membered heteroaromatics, including furan-, pyrazole-, isoxazole-, thiophene-, indole-, benzofuran- and indazolecarboxylic acids, with Selectfluor is reported. Fluorinated dimer products were observed for nitrogen-containing heteroaromatic carboxylic acids, such as indole and pyrazole. An effective method has been developed to synthesize the monomer of 2- and 3-fluoroindoles with Li2CO3 as base at low temperature.
Synthesis of pyrazole-3-carboxylates and pyrazole-1,5-dicarboxylates by one-pot cyclization of hydrazone dianions with diethyl oxalate
Dang, Tung T.,Dang, Tuan T.,Fischer, Christine,G?rls, Helmar,Langer, Peter
, p. 2207 - 2215 (2008/09/18)
The one-pot cyclization of hydrazone dianions with diethyl oxalate allows a convenient synthesis of pyrazole-3-carboxylates and pyrazole-1,5-dicarboxylates.
One-pot synthesis of pyrazole-5-carboxylates by cyclization of hydrazone 1,4-dianions with diethyl oxalate
Dang, Tuan Thanh,Dang, Tung Thanh,Langer, Peter
, p. 3591 - 3593 (2008/02/02)
The cyclization of hydrazone dianions with diethyl oxalate afforded pyrazole-5-carboxylates.
Isothiazoles. Part 3. Cycloadditions of Diazoalkanes to 3-Dialkylaminoisothiazole 1,1-Dioxides. Competitive Ring Cleavage in 3a,4-Dihydro-6aH-pyrazoloisothiazole 1,1-Dioxides: Formation of 2-Thia-3-azabicyclohex-3-ene 2,2-Dioxides and/or Pyrazoles
Clerici, Francesca,Ferrario, Tiziano,Gelmi, Maria Luisa,Marelli, Roberto
, p. 2533 - 2536 (2007/10/02)
3-Dialkylaminoisothiazole 1,1-dioxides 1 readily undergo cycloadditions with diazoalkanes 2.The reaction is characterized by high site- and regio-selectivity.Cycloadducts 3 and 4 were found to undergo straightforward thermolysis reactions at elevated temperature through two different paths characterized respectively by loss of nitrogen or sulfur dioxide and diethylcyanamide.The different transformations affording pyrazoles 6 and derivatives of the new heterocycle 2-thia-3-azabicyclohex-3-ene 2,2-dioxide 5 are discussed.
