The Chemistry of α-Haloketones and Their Utility in Heterocyclic Synthesis

Abstract

The molecular structures and spectral properties of α-haloketones as well as their syntheses are analyzed and reviewed. Their reactivity towards oxygen, nitrogen, and sulfur nucleophiles, carboxylic acids, carbon nucleophiles, alkenes, and alkynes are discussed.

Heterocyclic synthesis with 4-hydrazinopyridothienopyrimidines: Synthesis of pyridothienotriazolopyrimidines and heterocyclylpyridothienopyrimidines with biological interest

“…Based on these established biological activities, and in connection with our continuing interest in the synthesis of fused heterocycles [21][22][23], we have decided to synthesize a series of novel pyrido [3 ,2 :4,5]thieno [3,2-d]pyrimidines as compounds, which may possess a broad range of biological activity. Recently, we have reviewed the chemistry of α-haloketones and their utility in heterocyclic synthesis [24]. In the present work, we have extended the utility of an appropriate α-haloketone, namely N-acetylchloroacetamide (2), in synthesis of 4-hydrazinopyrido [3 ,2 :4,5]thieno [3,2-d]pyrimidines 7a,b as versatile precursors for the construction of a variety of unique polyfunctionally substituted heterocycles with enhanced biological significance.…”

Nuclear fluorination of 2,4-diarylthiazoles with Accufluor®

“…1. As shown in Scheme 1, the starting 2,4 diarylthiazoles were readily prepared by reaction of variously substituted phenacyl bromides with thiobenzamide in refluxing EtOH (i.e., the Hantzsch thiazole synthesis) [20].…”

Synthesis of 2-Aryl-4-(R-sulfanylmethyl)-3-methyl-6,7-dihydro-2H-pyrazolo[3,4-d]pyridazin-7-ones

“…The optimal bromination procedure was treatment of solutions of Ia-Ie in acetic acid with bromine in the presence of a catalytic amount of sulfuric acid. We thus obtained ethyl 1-aryl-4-(bromoacetyl)-5-methyl-1H-pyrazole-3-carboxylates IVa-IVe (Scheme 2).α-Halo ketones are convenient reagents for the alkylation of various nucleophiles [8]. Such transformations of bromo ketones IV could give rise to many polyfunctional 1-arylpyrazole derivatives.…”