98511-86-5Relevant academic research and scientific papers
Cyclocondensation of arylhydrazines with 1,3-bis(het)arylmonothio-1,3- diketones and 1,3-Bis(het)aryl-3-(methylthio)-2-propenones: Synthesis of 1-Aryl-3,5-bis(het)arylpyrazoles with complementary regioselectivity
Kumar, S. Vijay,Yadav, Santosh K.,Raghava,Saraiah,Ila,Rangappa,Hazra, Arpan
, p. 4960 - 4973 (2013/06/27)
Two efficient highly regioselective routes for the synthesis of unsymmetrically substituted 1-aryl-3,5-bis(het)arylpyrazoles with complementary regioselectivity starting from active methylene ketones have been reported. In the first protocol, the newly synthesized 1,3-bis(het)aryl-monothio-1,3-diketone precursors (prepared by condensation of active methylene ketones with het(aryl) dithioesters in the presence of sodium hydride) were reacted with arylhydrazines in refluxing ethanol under neutral conditions, furnishing 1-aryl-3,5-bis(het)arylpyrazoles 7, in which the het(aryl) moiety attached to the thiocarbonyl group of monothio-1,3-diketones is installed at the 3-position. In the second method, the corresponding 3-(methylthio)-1,3-bis(het)aryl-2- propenones (prepared in situ by base-induced alkylation of 1,3- monothiodiketones) were condensed with arylhydrazines in the presence of potassium tert-butoxide in refluxing tert-butyl alcohol, yielding 1-aryl-3,5-bis(het)arylpyrazoles 9 with complementary regioselectivity (method A). The efficiency of this protocol was further improved by developing a one-pot, three-component procedure for the synthesis of pyrazoles 9, directly from active methylene ketones, by reacting in situ generated 3-(methylthio)-1,3-bis(het)aryl-2-propenones with arylhydrazines in the presence of sodium hydride (instead of potassium tert-butoxide as base). The structures and regiochemistry of newly synthesized pyrazoles were confirmed from their spectral and analytical data along with X-ray crystallographic data of three pairs of regioisomers.
1,3-Diarylcycloalkanopyrazoles and diphenyl hydrazides as selective inhibitors of cyclooxygenase-2
Sui, Zhihua,Guan, Jihua,Ferro, Michael P.,McCoy, Kathy,Wachter, Michael P.,Murray, William V.,Singer, Monica,Steber, Michele,Ritchie, Dave M.,Argentieri, Dennis C.
, p. 601 - 604 (2007/10/03)
Novel 1,3-diarylcycloalkanopyrazoles 1, and diphenyl hydrazides 2 were identified as selective inhibitors of cyclooxygenase-2. The 1,3-diaryl substitution pattern of the pyrazole ring in 1 differentiates these compounds from most of the known selective COX-2 inhibitors that contain two aryl rings at the adjacent positions on a heterocyclic or a phenyl ring. Similarly, the two phenyl rings in 2 are also separated by three atoms. SAR of both phenyl rings in 1 and 2, and the aliphatic ring in 1 will be discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.
