Ionic Liquid Promoted Simple and Efficient Synthesis of β-Enamino Esters and β-Enaminones from 1,3-Dicarbonyl Compounds — One-Pot, Three-Component Reaction for the Synthesis of Substituted Pyridines.
A facile enamination of 1,3-dicarbonyl compounds with amines has been developed that affords good to excellent yields of β-enamino esters and β-enaminones using Brønsted acidic ionic liquid 1-methylimidazolium trifluoroacetate ([Hmim]+Tfa) at room temperature. This methodology has been extended for the synthesis of substituted pyridines in excellent yield by a one-pot, three-component reaction of 1,3-dicarbonyl compounds, ammonium acetate, and alkynone in the presence of [Hmim]+Tfa.Key words: ionic liquid, β-enaminones, β-enamino esters, 1,3-dicarbonyl compounds, amines, pyridines.
An efficient synthesis of 10 4,4′-(arylmethylene)bis(3-carboxymethyl-1-phenyl-1 H-pyrazol-5-ol)s, eight of which are novel, was achieved by a one-pot three-component reaction of phenylhydrazine, dimethyl acetylenedicarboxylate and an arylaldehyde using bis(1(3-methoxysilylpropyl)-3-methyl-imidazolium) copper tetrachloride tethered to colloidal silica nanoparticles as catalyst under microwave irradiation in water. The advantages of the present process are atom economy, high catalytic activity, excellent yields, short reaction times and utilisation of microwave heating as a clean procedure. The catalyst was recyclable.
AbstractA one-pot three component reaction of benzaldehydes, 1H-tetrazole-5-amine, and 3-cyanoacetyl indole in the presence of a new hexamethylenetetramine-based ionic liquid/MIL-101(Cr) metal–organic framework as a recyclable catalyst was explored. This novel catalyst, which was fully characterized by XRD, FE-SEM, EDX, FT-IR, TGA, BET, and TEM exhibited outstanding catalytic activity for the preparation of a range of pharmaceutically important tetrazolo[1,5-a]pyrimidine-6-carbonitriles with good to excellent yields in short reaction time.
A simple and efficient synthetic protocol has been developed involving a one-pot three-component reaction of a 2-chlorobenzazole, piperazine, and an arenesulfonyl chloride under aqueous conditions at room temperature in the absence of a catalyst, ligand, or base. By using this protocol, a variety of 2-[4-(arylsulfonyl)piperazin-1-yl]-1,3-benzothiazole, -1H-benzimidazole, and -1,3-benzoxazole derivatives were synthesized in excellent yields.
A green, convenient and tandem procedure for the efficient synthesis of highly substituted indeno[1,2-b]pyrrole and acenaphtho[1,2-b]pyrrole derivatives by domino three-component reaction of tryptamine/benzylamine, 1,3-dicarbonyl compounds and ninhydrin/ acenaphthenequinone is described. The significant features of this procedure were characterized by mild reaction conditions, high yields, operational simplicity and it being environmentally benign.
Synthesis of tetrazolo[1,5-a]pyrimidine-6-carbonitriles using HMTA-BAIL@MIL-101(Cr) as a superior heterogeneous catalyst