13370-06-4Relevant articles and documents
N-triflyl-propiolamides: Preparation and transamidation reactions
Fiore, Vito A.,Maas, Gerhard
, p. 3586 - 3595 (2019/05/27)
N-Trifluoromethylsulfonyl-propiolamides have been prepared by two methods: a) N-triflation of secondary acetylenic carboxanilides, prepared in two steps from terminal alkynes, with triflic anhydride (Tf2O) and b) from terminal alkynes and an aryl or alkyl isocyanate followed by Tf2O in a consecutive one-pot reaction. The title compounds are bench-stable and insensitive to water and alcohols but amenable to transamidation reactions with a wide range of amine nucleophiles. Conversely, they are excellent reagents for the propynoylation of ammonia, primary and secondary amines, anilines, and hydrazines.
Synthesis, crystal structure, and fungicidal activity of novel 1,5-diaryl-1H-pyrazol-3-Oxy derivatives containing oxyacetic acid or oxy(2-thioxothiazolidin-3-yl)ethanone moieties
Liu, Yuanyuan,He, Guangke,Kai, Chen,Li, Yufeng,Zhu, Hongjun
, p. 1370 - 1375 (2013/02/22)
A series of novel 1,5-diaryl-1H-pyrazol-3-oxy derivatives containing oxyacetic acid or oxy(2-thioxothiazolidin-3-yl)ethanone moieties were prepared from methyl 3-arylacrylates via a serial of reactions included addition-cyclization, oxidation, substitution, hydrolysis, and condensation. Their structures were confirmed by 1H-NMR, 13C-NMR, IR, and elemental analysis. In addition, the crystal structure of the compound 2-(1,5-diphenyl-1H-pyrazol-3-yloxy)-1-(2-thioxothiazolidin-3-yl)ethanone was determined by single crystal X-ray diffraction analysis. Bioassay results indicated that the compound 2-(5-(4-chlorophenyl)-1-phenyl-1H-pyrazol-3-yloxy)- 1-(2-thioxo-thiazolidin-3-yl)ethanone exhibited moderate inhibitory activity against Gibberella zeae at the dosage of 10 μg mL-1.
5-Iodo-3-ethoxypyrazoles: An entry point to new chemical entities
Guillou, Sandrine,Janin, Yves L.
experimental part, p. 4669 - 4677 (2010/08/06)
Our program, which has focused on the preparation of new pyrazole derivatives, has led us to report here an original and simplified preparation of ethyl 3-ethoxy-lW-pyrazole-4-carboxylate. This is based on the reaction of hydrazine monohydrochloride and diethyl 2-(ethoxymethylene)malonate. Further transformations of this key compound allowed the preparation of the two possible iodinated isomers, namely, 3-ethoxy-4-iodo- and 3-ethoxy-5-iodo-1H-pyrazole. These compounds have opened the way to a quick access to many original pyrazole series. As an illustration, we report here on the selectivity of N-arylation, by using the Lam and Cham method, the C4- and C5-arylation of some of these 3-ethoxy-pyrazole derivatives by using the Suzuki-Miyaura reaction, and C5-benzylation reactions by means of the Negishi reaction. This was followed by hydrolysis of the ethoxy group, which led to the corresponding pyrazol-3-one derivatives. As a conclusion of this work, we conducted an investigation into the regiochemistry of the condensation between diethyl 2-(ethoxymethylene) malonate and the hydrochloride salts of methyl, benzyl, or phenyl hydrazine.
