Green Method for the Synthesis of Chromeno[2,3-c]pyrazol-4(1H)-ones through Ionic Liquid Promoted Directed Annulation of 5-(Aryloxy)-1H-pyrazole-4-carbaldehydes in Aqueous Media
摘要:
The first classical heterocyclic ionic liquid (IL) promoted C-H bond oxidant cross-doupling,reaction for the intramolecular annulation of 5-(aryloxy)-1H-pyrazole-4-carbal- dehydes to chromeno[2,37c]pyrazol-4(1H)-ones has been disclosed The promoter 1,3-dibutyl-1H-benzo[d]fl 2 3]- triazol-34-ium bromide can be easily recycled reused with the same efficacies for at least five cycles in aqueous medium The strategy works smoothly and provides applicable protocol to construct a Wide range of products.
Intermolecular tandem copper-catalyzed O-arylation-oxidative acylation (cross dehydrogenative coupling-CDC) has been developed under air as an oxidant. The reaction between 2,4-dihydro-3H-pyrazol-3-ones and ortho-halo aryl carboxaldehydes furnished the corresponding chromone fused pyrazoles, in a straightforward manner. The synthetic utility of the presented tandem catalysis has been demonstrated with the synthesis of an A(2)-subtype selective adenosine receptor antagonist in only two steps.[GRAPHICS]
Heterocyclic analogs of xanthones
作者:A. S. Sarenko、I. Ya. Kvitko、L. S. �fros
DOI:10.1007/bf00487468
日期:1972.6
Synthesis of Some 1-Aryl-4-(2-hydroxybenzoyl)-pyrazol-5-one and 1-Aryl[1]benzopyrano [2,3-<i>c</i>]pyrazol-4(1<i>H</i>)-one Derivatives from 3-Acyl-4-hydroxycoumarins
作者:Bernard Chantegrel、Abdel-Ilah Nadi、Suzanne Gelin
DOI:10.1055/s-1983-30286
日期:——
Heterocyclic analogs of xanthones chromono(3,2-d)pyrazoles