92070-54-7Relevant academic research and scientific papers
Unexpected ring opening of pyrazolines with activated alkynes: synthesis of 1H-pyrazole-4,5-dicarboxylates and chromenopyrazolecarboxylates
Bhimapaka, China Raju,Kolla, Sai Teja,Rayala, Nageswara Rao,Sridhar, Balasubramanian
supporting information, p. 334 - 338 (2022/01/20)
1H-Pyrazole-4,5-dicarboxylates and chromenopyrazole carboxylates were prepared by reacting pyrazolines with activated alkynes under neat conditions without a catalyst. The products were formed via unexpected ring opening of pyrazolines with the elimination of styrene/ethylene. These types of transformations are unknown and the products formed were confirmed using their spectral/analytical data. In addition, the structures of compounds 5e and 5n were confirmed by single-crystal X-ray analysis. Control experiments were conducted to support the proposed reaction mechanism.
TBHP/Cu(OAc)2 mediated oxidation of pyrazolines: A convenient method for the preparation of pyrazoles
Kolla, Sai Teja,Somanaboina, Ramya,Bhimapaka, China Raju
supporting information, p. 1425 - 1432 (2021/02/27)
An efficient and simple oxidative protocol has been developed for the preparation of pyrazoles from pyrazolines mediated by TBHP/Cu(OAc)2 at room temperature. The present protocol has been successfully applied for the preparation of various pyrazole compounds from heterocyclic pyrazolines.
Zinc-catalyzed synthesis of pyrazolines and pyrazoles via hydrohydrazination
Alex, Karolin,Tillack, Annegret,Schwarz, Nicolle,Beller, Matthias
supporting information; experimental part, p. 2377 - 2379 (2009/05/27)
(Chemical Equation Presented) A novel regioselective synthesis of aryl-substituted pyrazolines and pyrazoles has been developed. Substituted phenylhydrazines react with 3-butynol in the presence of a catalytic amount of zinc triflate to give pyrazoline derivatives. The resulting products are easily oxidized in a one-pot procedure to the corresponding pyrazoles.
Aqueous N-heterocyclization of primary amines and hydrazines with dihalides: Microwave-assisted syntheses of N-azacycloalkanes, isoindole, pyrazole, pyrazolidine, and phthalazine derivatives
Ju, Yuhong,Varma, Rajender S.
, p. 135 - 141 (2007/10/03)
The synthesis of nitrogen-containing heterocycles from alkyl dihalides (ditosylates) and primary amines and hydrazines via a simple and efficient cyclocondensation in an alkaline aqueous medium that occurs under microwave irradiation is described. This improved greener synthetic methodology provides a simple and straightforward one-pot approach to the synthesis of a variety of heterocycles, such as substituted azetidines, pyrrolidines, piperidines, azepanes, N-substituted 2,3-dihydro-1H-isoindoles, 4,5-dihydropyrazoles, pyrazolidines, and 1,2-dihydrophthalazines.
Microwave-assisted cyclocondensation of hydrazine derivatives with alkyl dihalides or ditosylates in aqueous media: Syntheses of pyrazole, pyrazolidine and phthalazine derivatives
Ju, Yuhong,Varma, Rajender S.
, p. 6011 - 6014 (2007/10/03)
Direct syntheses of 4,5-dihydro-pyrazole, pyrazolidine, and 1,2-dihydro-phthalazine derivatives via double-alkylation of hydrazines by alkyl dihalides or ditosylates were accomplished in aqueous media under microwave irradiation conditions; the environmen
