209907-29-9Relevant academic research and scientific papers
Visible-light-activated C-C and C-N bond formation in the synthesis of imidazo[1,2-: A] pyridines and imidazo[2,1- b] thiazoles under catalyst and solvent-free conditions
Shivhare, Km Neha,Jaiswal, Manish K.,Srivastava, Anushree,Tiwari, Saurabh K.,Siddiqui
, p. 16591 - 16601 (2018/10/24)
The formation of a 3-aminoimidazo-fused heterocyclic compound and its derivatives through a multicomponent one-pot reaction, activated by visible light, is reported. The noticeable feature of this protocol is the utilization of a universally available energy source to activate the reaction. The reported methodology is the first protocol that represents the implementation of visible light for this Ugi-type synthesis from 2-aminoheterocycles, aldehydes, and isocyanides as well as offers the advantages of improved selectivity, outstanding yields, solvent and catalyst-free conditions, environmental sustainability and convenient access to starting materials.
Microwave-assisted three-component reaction in conventional solvents and ionic liquids for the synthesis of amino-substituted imidazo[1,2-a]pyridines
Mert-Balci, Fadime,Conrad, Juergen,Beifuss, Uwe
, p. 243 - 256 (2013/09/24)
3-Amino-substituted imidazo[1,2-a]pyridines can be prepared with yields up to 98% within a few minutes by microwave-assisted three-component reaction between 2-aminopyridines, aldehydes and isocyanides using montmorillonite as the catalyst and toluene as the solvent. The organic solvent can be replaced by ionic liquids. With guanidinium salts the microwave-assisted reaction can be performed in the absence of any further catalyst. ARKAT-USA, Inc.
Antibacterial activities of Groebke-Blackburn-Bienayme-derived imidazo[1,2-a]pyridin-3-amines
Shukla, Nikunj M.,Salunke, Deepak B.,Yoo, Euna,Mutz, Cole A.,Balakrishna, Rajalakshmi,David, Sunil A.
, p. 5850 - 5863 (2012/10/30)
We sought to explore the imidazo[1,2-a]pyridin-3-amines for TLR7 (or 8)-modulatory activities. This chemotype, readily accessed via the Groebke-Blackburn-Bienayme multi-component reaction, resulted in compounds that were TLR7/8-inactive, but exhibited bacteriostatic activity against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). To investigate the mechanism of antibacterial activity of this new chemotype, a resistant strain of S. aureus was generated by serially passaging the organism in escalating doses of the most active analogue. A comparison of minimum inhibitory concentrations (MICs) of known bacteriostatic agents in wild-type and resistant strains indicates a novel mechanism of action. Structure-activity relationship studies have led to the identification of positions on the scaffold for additional structural modifications that should allow for the introduction of probes designed to examine cognate binding partners and molecular targets, while not significantly compromising antibacterial potency.
Structure-activity relationships in human toll-like receptor 8-active 2,3-diamino-furo[2,3- c ]pyridines
Salunke, Deepak B.,Yoo, Euna,Shukla, Nikunj M.,Balakrishna, Rajalakshmi,Malladi, Subbalakshmi S.,Serafin, Katelyn J.,Day, Victor W.,Wang, Xinkun,David, Sunil A.
, p. 8137 - 8151 (2012/11/07)
In our ongoing search toward identifying novel and synthetically simpler candidate vaccine adjuvants, we hypothesized that the imidazo[1,2-a]pyrazines, readily accessible via the Groebke-Blackburn-Bienaymé multicomponent reaction, would possess sufficient structural similarity with TLR7/8-agonistic imidazoquinolines. With pyridoxal as the aldehyde component, furo[2,3-c]pyridines, rather than the expected imidazo[1,2-a]pyridines, were obtained, which were characterized by NMR spectroscopy and crystallography. Several analogues were found to activate TLR8-dependent NF-κB signaling. In a focused library of furo[2,3-c]pyridines, a distinct SAR was observed with varying substituents at C2. In human PBMCs, none of the furo[2,3-c]pyridines showed any proinflammatory cytokine induction but upregulated several chemokine ligand genes. In immunization studies in rabbits, the most active compound showed prominent adjuvantic effects. The complete lack of proinflammatory cytokine induction coupled with strong adjuvantic activity of the novel furo[2,3-c]pyridines render this hitherto unknown chemotype an attractive class of compounds which are expected to be devoid of local or systemic reactogenicity.
Microwave-accelerated three-component condensation reaction on clay: Solvent-free synthesis of imidazo[1,2-a] annulated pyridines, pyrazines and pyrimidines
Varma, Rajender S.,Kumar, Dalip
, p. 7665 - 7669 (2007/10/03)
A rapid one-pot synthesis of imidazo[1,2-a] annulated pyridines, pyrazines and pyrimidines is described that occurs in the presence of recyclable montmorillonite K 10 clay under solvent-free conditions using microwave irradiation.
Parallel synthesis of 3-aminoimidazo[1,2-a]pyridines and pyrazines by a new three-component condensation
Blackburn, Christopher,Guan, Bing,Fleming, Paul,Shiosaki, Kazumi,Tsai, Shirling
, p. 3635 - 3638 (2007/10/03)
A three-component condensation reaction between 2-aminopyridine, an aldehyde and an isonitrile catalyzed by scandium triflate affords derivatives of 3-aminoimidazo[1,2-a]pyridine; aminopyrazine reacts similarly. A library of heterocycles, prepared in high yield by parallel synthesis and purification on an ion-exchange resin, was subjected to further reactions at the amino group.
