41862-16-2Relevant academic research and scientific papers
Construction of Dihydropyrido[2,3- d]pyrimidine Scaffolds via Aza-Claisen Rearrangement Catalyzed by N-Heterocyclic Carbenes
Dzieszkowski, Krzysztof,Barańska, Izabela,Rafiński, Zbigniew
, p. 6645 - 6662 (2020/07/14)
N-Heterocyclic carbenes (NHCs) catalyzing aza-Claisen rearrangement of α,β-unsaturated enals with cyclic vinylogous amides under oxidative conditions generating potentially biologically active dihydropyridinone-fused uracils have been developed. This strategy represents a unique NHC-activation-based path with the use of 6-aminouracils as stable α,β-diEWG cyclic vinylogous amides for the efficient synthesis of bicyclic N-unprotected lactams similar to those in many useful drugs.
Pyrimidopteridine N-Oxide Organic Photoredox Catalysts: Characterization, Application and Non-Covalent Interaction in Solid State
Hauptmann, Richy,Petrosyan, Andranik,Fennel, Franziska,Argüello Cordero, Miguel A.,Surkus, Annette-E.,Pospech, Jola
, p. 4325 - 4329 (2019/03/29)
Herein we report the photo- and electrochemical characterization of pyrimidopteridine N-oxide-based heterocycles. The potential of their application as organic photoredox catalysts is showcased in the photomediated contra-thermodynamic E→Z isomerization of cinnamic acid derivatives and oxidative cyclization of 2-phenyl benzoic acid to benzocoumarin using molecular oxygen as a mild oxidant. Furthermore, unprecedented intermolecular non-covalent n–π-hole interactions in solid state are discussed based on crystallographic and theoretical data.
Novel 1,3-disubstituted 8-(1-benzyl-1H-pyrazol-4-yl) xanthines: High affinity and selective A2B adenosine receptor antagonists
Kalla, Rao V.,Elzein, Elfatih,Perry, Thao,Li, Xiaofen,Palle, Venkata,Varkhedkar, Vaibhav,Gimbel, Arthur,Maa, Tennig,Zeng, Dewan,Zablocki, Jeff
, p. 3682 - 3692 (2007/10/03)
Adenosine has been suggested to induce bronchial hyperresponsiveness in asthmatics, which is believed to be an A2B adenosine receptor (AdoR) mediated pathway. We hypothesize that a selective, high-affinity A2B AdoR antagonist may provide therapeutic benefit in the treatment of asthma. In an attempt to identify a high-affinity, selective antagonist for the A 2B AdoR, we synthesized 8-(C-4-pyrazolyl) xanthines. Compound 22, 8-(1H-pyrazol-4-yl)-1,3-dipropyl xanthine, is a N-1 unsubstituted pyrazole derivative that has favorable binding affinity (Ki = 9 nM) for the A2B AdoR, but it is only 2-fold selective versus the A1 AdoR. Introduction of a benzyl group at the N-1-pyrazole position of 22 resulted in 19, which had moderate selectivity. The initial focus of the SAR study was on the preparation of substituted benzyl derivatives of 19 because the corresponding phenyl, phenethyl, and phenpropyl derivatives showed a decrease in A2B AdoR affinity and selectivity relative to 19. The preferred substitution on the phenyl ring of 19 contains an electron-withdrawing group, specifically F or CF3 at the m-position, as in 33 and 36 respectively, increases the selectivity while retaining the affinity for the A2B AdoR. Exploring disubstitutions on the phenyl ring of derivatives 33 and 36 led to the 2-chloro-5-trifluoromethylphenyl derivative 50, which retained the A2B AdoR affinity but enhanced the selectivity relative to 36. After optimization of the substitution on the 8-pyrazole xanthine, 1,3-disubstitution of the xanthine core was explored with methyl, ethyl, butyl, and isobutyl groups. In comparison to the corresponding dipropyl analogues, the smaller 1,3-dialkyl groups (methyl and ethyl) increased the A2B AdoR binding selectivity of the xanthine derivatives while retaining the affinity. However, the larger 1,3-dialkyl groups (isobutyl and butyl) resulted in a decrease in both A2B AdoR affinity and selectivity. This final SAR optimization led to the discovery of 1,3-dimethyl derivative 60, 8-(1-(3-(trifluoromethyl) benzyl)-1H-pyrazol-4-yl)-1,3-dimethyl xanthine, a high-affinity (Ki = 1 nM) A2B AdoR antagonist with high selectivity (990-, 690-, and 1000-) for the human A1, A2A, and A3 AdoRs.
Preparation of nucleoside uronamides as A3 adenosine receptor agonists.
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, (2008/06/13)
The present invention provides N 6-benzyladenosine-5'-N-uronamide and related substituted compounds, particularly those containing substituents on the benzyl and/or uronamide groups, and modified xanthine ribosides, as well as pharmaceutical compositions containing such compounds. The present invention also provides a method of selectively activating an A 3 adenosine receptor in a mammal, which method comprises acutely or chronically administering to a mammal in need of selective activation of its A 3 adenosine receptor a therapeutically effective amount of a compound which binds with the A. sub.3 receptor so as to stimulate an A 3 receptor-dependent response.
Structure-Activity Relationships of 1,3-Dialkylxanthine Derivatives at Rat A3 Adenosine Receptors
Kim, Hea Ok,Ji, Xiao-duo,Melman, Neli,Olah, Mark E.,Stiles, Gary L.,Jacobson, Kenneth A.
, p. 3373 - 3382 (2007/10/02)
1,3-Dialkylxanthine analogues containing carboxylic acid and other charged groups on 8-position substituents were synthesized.These derivatives were examined for affinity in radioligand binding assays at rat brain A3 adenosine receptors stably
