A facile synthesis of pyrazoles with multi-point structural diversity by 1,3-dipolar cycloaddition was written by Cheung, Kwai Ming J.;Reynisson, Johannes;McDonald, Edward. And the article was included in Tetrahedron Letters in 2010.Category: pyrazoles-derivatives The following contents are mentioned in the article:
We describe the synthesis of diverse pyrazoles by 1,3-dipolar cycloaddition of Et diazoacetate with various acetylenes in refluxing toluene. The product pyrazoles are useful starting points for preparing a diverse collection of trisubstituted pyrazole carboxamides. For aryl and heteroaryl alkynes a single product is obtained while alkyl alkynes afford a ca. 6:1 mixture of regioisomers. The observed regioselectivity for the cycloaddition step and the ease of reaction are consistent with predictions derived from computing the HOMO-LUMO energies of the reactants. This study involved multiple reactions and reactants, such as Ethyl 4-(hydroxymethyl)-1H-pyrazole-3-carboxylate (cas: 61453-49-4Category: pyrazoles-derivatives).
Ethyl 4-(hydroxymethyl)-1H-pyrazole-3-carboxylate (cas: 61453-49-4) belongs to pyrazole derivatives. An alternative way to synthesize multisubstituted pyrazoles is the Csingle bondH arylation of simple pyrazoles. Pyrazole rings have been used as core components of several leading non-steroidal anti-inflammatory drugs (NSAIDs) and antihypertensive drugs. It has also been found to be useful as a bifunctional ligand for metal catalysis.Category: pyrazoles-derivatives
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics