Halogen dance in pyrazole 1-oxides: synthesis of pyrazolo[3,4-c]quinoline 1-oxides

Electrophilic Amination of 4-Fluorophenol with Diazenes: A Complete Removal of the Fluorine Atom

“…A similar observation was reported for the case of halogenated benzenes by Wotiz and Huba . This transformation, also known as the “halogen dance”, was later thoroughly investigated by several groups. − In contrast, acid-promoted halogen migration rarely occurs with aromatic molecules and is limited to bromine 7 and iodine . As a part of our continuing interest in hydrazides 9 and other N−N-containing compounds, we recently reported on the electrophilic amination of 4-halophenols and 2,4-dihalophenols with diisopropyl diazenedicarboxylate in the presence of ZrCl 4 as a Lewis acid.…”

The use of the Comins-Meyers Amide in Synthetic Chemistry: An Overview

“…12). Such a ring system displays significant biological activities, good affinity and selectivity towards adenosine A 3 , GABA and NMDA receptors [21].…”

“…Scheme 11: Synthesis of the serotonin re-uptake inhibitors.Similarly, Eskildsen et al used the Meyers formylation reagent (1) in the synthesis of pyrazolo[3,4-c] quinoline 1-oxides (41) (Scheme 12). Such a ring system displays significant biological activities, good affinity and selectivity towards adenosine A 3 , GABA and NMDA receptors[21].…”

Cascade bicyclization of triethylammonium thiolates with hydrazines: efficient access to pyrazolo[3,4-c]quinolines

“…7 Accordingly, the construction of functional pyrazolo[3,4- c ]quinolines has unarguably become an important pursuit of the goal by chemists. Traditionally, three general strategies have been reported including the direct functionalization of the pyrazolo[3,4- c ]quinolone, 8 the merging of a pyrazole ring into the pre-existing indole and quinoline skeletons, 9 and the multistep cyclizations of anilines and pyrazole precursor 10 as well as domino cyclization of (indol-3-yl)-2-oxoacetates with hydrazines. 11 Very recently, Li and co-workers report a dehydrogenative [2 +2 + 1] heteroannulation of N -( o -alkenylaryl) imines for accessing pyrazolo[3,4- c ]quinolines.…”