55774-20-4Relevant academic research and scientific papers
Pd(ii)-Catalyzed alkyne annulation through allylic isomerization: synthesis of spiro-cyclopentadiene pyrazolones
Changmai, Sumi,Sultana, Sabera,Sarma, Bipul,Gogoi, Sanjib
supporting information, p. 6027 - 6030 (2021/06/21)
The Pd(ii)-catalyzed activation of Csp2-H bond and double alkyne annulation which proceedsviaallylic isomerization is reported for the first time. This reaction of antipyrines with alkynes provides an efficient synthetic route for the biologically important spiro-cyclopentadiene pyrazolones. In the presence of Lawesson's reagent, this Pd(ii)-catalyzed annulation reaction affords another spiro-cyclopentadiene pyrazolone which displays very good fluorescence properties.
Metal-Free Direct C–H Thiolation and Thiocyanation of Pyrazolones
Kittikool, Tanakorn,Yotphan, Sirilata
, (2020/02/13)
Metal-free approach for direct C–H thiolation and thiocyanation of N-substituted pyrazolones with disulfides and thiocyanate salts, respectively, are developed. These reactions allow the C–S bond coupling to proceed effectively under mild conditions, providing useful and convenient methods for preparation of a series of 4-thio-substituted pyrazolone analogues, which have potential applications in organic, medicinal and material chemistry. Preliminary mechanistic investigation suggested that radical processes are likely to involve in these transformations.
DABCO-catalyzed silver-promoted direct thiolation of pyrazolones with diaryl disulfides
Thupyai, Akkharaphong,Pimpasri, Chaleena,Yotphan, Sirilata
, p. 424 - 432 (2018/02/06)
A highly efficient protocol for a direct thiolation of N-substituted pyrazolones with diaryl disulfides is described. Using a combination of DABCO and silver(i) acetate, the C-S bond formation proceeds smoothly at room temperature under mild and easy to handle conditions. This synthetic strategy offers a convenient and direct modification of antipyrine and other pyrazolone substrates, giving a series of aryl sulfide-substituted pyrazolone products in moderate to excellent yields.
Copper/Persulfate-Promoted Oxidative Decarboxylative C?H Acylation of Pyrazolones with α-Oxocarboxylic Acids: Direct Access to 4-Acylpyrazolones under Mild Conditions
Kittikool, Tanakorn,Thupyai, Akkharaphong,Phomphrai, Khamphee,Yotphan, Sirilata
, p. 3345 - 3355 (2018/09/10)
A facile and efficient oxidative C?H acylation of N-substituted pyrazolones using α-oxocarboxylic acids as an acyl group source was developed. A combination of Cu(OAc)2 and K2S2O8 enables the reaction to proceed smoothly under air and provides a wide array of 4-acylpyrazolone products in moderate to excellent yields. The mechanism of this transformation is believed to proceed via a copper-induced decarboxylation to form the acyl-copper species. This method provides a convenient and useful route for a direct installation of an acyl moiety into bioactive pyrazolone derivatives, which can be further utilized in many applications. (Figure presented.).
Room-temperature direct alkenylation of 5-pyrazolones
Yang, Yiwen,Gong, Hao,Kuang, Chunxiang
supporting information, p. 5276 - 5281 (2013/09/02)
A mild and efficient method for the direct alkenylation of 5-pyrazoles by Pd-catalyzed C-H bond activation is described. The reaction smoothly proceeds at room temperature to provide products in up to 92 % yield. Heterocycles containing the 5-pyrazolone moiety are synthesized by an oxidative Heck-type reaction. The direct alkenylation of 5-pyrazolones at room temperature through Pd-catalyzed C-H bond activation is described. Copyright
NOVEL UREIDO - AND AMIDO-PYRAZOLONE DERIVATIVES
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Page 20, (2008/06/13)
The present invention provides compounds of formula (I); wherein each of R1 to R4 is independently selected from hydrogen, a halogen, a substituted or unsubstituted cyclic and heterocyclic moiety, substituted or unsubstituted, linear or branched alkyl, alkyloxy, alkylcarbonyl, alkyloxycarbonyl, alkenyl, alkenyloxy, alkenylcarbonyl, alkenyloxycarbonyl, alkynyl, alkynyloxy, alkynylcarbonyl, alkynyloxycarbonyl, aryl, benzyl, arlyoxy, arylcarbonyl, aryloxycarbonyl and sulphur equivalents of said oxy, carbonyl and oxycarbonyl moieties, and A is NH, or (CH2)n, where n is preferably 0, 1 or 2. The invention also relates to methods for preparing the compounds and their uses as CCK receptor ligands and CCK antagonists.
