Table 3 - uploaded by Vikas Tyagi
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The dimethylamino functionality is generally introduced onto the 3,5-dihydro-4H-imidazol-4-one skeleton by treatment of a halogenated derivative with low-boiling dimethylamine at a high temperature and pressure. The corresponding aliphatic ethers are usually prepared by Williamson ether synthesis, but the available transition-metal-catalyzed method...
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Context 1
... decided to apply the experience that we gained from the above study to the etherification of 2-(methylsulfa- nyl)-3,5-dihydro-4H-imidazol-4-ones at the C2-position by using alcohols. To identify suitable conditions for the etherification, we chose the imidazolone 14a and butanol as model coupling partners, and we examined the reaction in the presence of various bases and at various tempera- ture (Table 3). Of the three bases that we examined, potas- sium carbonate was found to be the best, giving ether 15a in 83% yield when butanol was used as the solvent at 160 °C (Table 3, entry 2). ...
Context 2
... identify suitable conditions for the etherification, we chose the imidazolone 14a and butanol as model coupling partners, and we examined the reaction in the presence of various bases and at various tempera- ture (Table 3). Of the three bases that we examined, potas- sium carbonate was found to be the best, giving ether 15a in 83% yield when butanol was used as the solvent at 160 °C (Table 3, entry 2). Sodium carbonate and potassi- um hydroxide gave poor yields of 15a (entries 3 and 4), and the reaction did not proceed in the absence of a base (entry 1). ...
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Citations
... Depending on the nature and the amount of the acid used, thioglycolurils 23 either recovered (AcOH) or underwent the Dimroth-type rearrangement to give 2-hydrazonoimidazo[4,5-d]thiazol-5-one derivatives (HCl). 32 Khan et al. 33 studied nucleophilic substitution of the methylthio group in 2-methylsulfanylimidazolines 27 on treatment with aqueous DMF or aliphatic alcohols. It was found that the substituent at the nitrogen atom exerted a dramatic eff ect on the path of the reaction occurring at heating of compounds 27 in DMF-H 2 O (1 : 1) in the presence of K 2 CO 3 . ...
... Reagents and conditions: 1) MeI, 2% KOH in EtOH, ~20 C, 30 min; 2) EtOH-HCl (1 : 1), , 6 h. hydantoins 20a,k-p, while in the absence of the substituent at the nitrogen atom (R 2 = H) 2-(dimethylamino)imid azolinones 28a-h predominated (Scheme 13).Khan et al.33 suggested that in the aqueous DMF N-substituted derivatives 27i-o underwent nucleophilic substitution at the C(2) position with the water molecule ...
The review is focused on the desulfurization of imidazolidine-2-thiones to imidazolidin-2-ones, which are widely applied in the synthesis of natural and synthetic practically useful compounds, primarily biologically active substances. The described methods are systematized in accordance to the key transformations, namely, nucleophilic substitution, oxidation, and more complex cascade reactions.
... The UPLC/MS purity of all final compounds was determined (%). Synthesis of compounds 6, 18-20, 22, 25-30, 32, 35 and 36 were described earlier [15,25,26,[38][39][40][41][42]. ...
Searching for new chemosensitizers of bacterial multidrug resistance (MDR), chemical modifications of (Z)-5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-4(5H)-one (6) were performed. New compounds (7–17), with fused aromatic rings at position 5, were designed and synthesized. Crystallographic X-ray analysis proved that the final compounds (7–17) were substituted with tertiary amine-propyl moiety at position 3 and primary amine group at 2 due to intramolecular Dimroth rearrangement. New compounds were evaluated on their antibiotic adjuvant properties in either Gram-positive or Gram-negative bacteria. Efflux pump inhibitor (EPI) properties towards the AcrAB-TolC pump in Enterobacter aerogenes (EA289) were investigated in the real-time efflux (RTE) assay. Docking and molecular dynamics were applied to estimate an interaction of compounds 6–17 with penicillin binding protein (PBP2a). In vitro ADME-Tox properties were evaluated for compound 9. Most of the tested compounds reduced significantly (4-32-fold) oxacillin MIC in highly resistant MRSA HEMSA 5 strain. The anthracene-morpholine derivative (16) was the most potent (32-fold reduction). The tested compounds displayed significant EPI properties during RTE assay (37–97%). The naphthyl-methylpiperazine derivative 9 showed the most potent “dual action” of both oxacillin adjuvant (MRSA) and EPI (E. aerogenes). Molecular modeling results suggested the allosteric mechanism of action of the imidazolones, which improved binding of oxacillin in the PBP2a active site in MRSA.
Реакцией 2-фенил-4-(4-бензоилоксиарилиден)-5(4Н)-оксазолонов с соответствующими диаминами были получены бисамиды, содержащие в молекуле двa фрагментa N,О-дибензоил-α,β-дегидротирозина. Из последних О-бензоильную защитную группу удаляли N1,N1-ди-метилпропан-1,3-диамином. Циклизация полученных бисамидов в соответствующие бисимидазолоны была проведена в диметилформамиде 1,1,1,3,3,3-гексаметилдисилазаном. Изучены антирадикальные и антихолинэстеразные свойства синтезированных соединений. 2-ֆենիլ-4-(4-բենզոիլօքսիարիլիդեն)-5(4H)-օքսազոլոնների փոխազդեցությամբ 1,4–տետրամեթիլեն– և 1,6–հեքսամեթիլենդիամինների հետ սինթեզվել են իրենց մոլեկուլում երկու N,O- դիբենզոիլ – α,β– դեհիդրոթիրոզինի մնացորդ պարունակող բիսամիդներ։ Վերջիններից N1,N1-դիմեթիլպրոպան-1,3-դիամինով հեռացվել է O-բենզոիլ պաշտպանող խումբը։ Ստացվածդիամիդների ցիկլումը համապատասխան բիսիմիդազոլոնների իրականացվել է դիմեթիլֆորմամիդում 1,1,1,3,3,3-հեքսամեթիլդիսիլազանի միջոցով։ Ուսումնասիրվել են սինթեզված միացությունների հակառադիկալային և հակախոլինէսթերազային հատկությունները։ The reaction of 2-phenyl-4-(4-benzoyloxyarylidene)-5(4H)-oxazolones with the corresponding 1,4-tetramethylene- and 1,6-hexamethylenediamines gave bisamides containing two fragments of N,O-dibenzoyl-α,β-dehydrotyrosine in the molecule. The O-benzoyl protecting group was removed from the latter with N1,N1-dimethylpropane-1,3-diamine. Cyclization of the obtained bis-amides to the corresponding bisimidazolones was carried out in dimethylformamide with 1,1,1,3,3,3-hexamethyldisilazane. Antiradical and anticholinesterase properties of the synthesized compounds were studied.
The review highlights the hydantoin syntheses presented from the point of view of the preparation methods. Novel synthetic routes to various hydantoin structures, the advances brought to the classical methods in the aim of producing more sustainable and environmentally friendly procedures for the preparation of these biomolecules, and a critical comparison of the different synthetic approaches developed in the last twelve years are also described. The review is composed of 95 schemes, 8 figures and 528 references for the last 12 years and includes the description of the hydantoin-based marketed drugs and clinical candidates.
A novel and robust route for the synthesis of diversely substituted isoindoline skeletons through a ligand-free Pd-catalyzed cascade consisting of isocyanide insertion into Ugi-tetrazole has been developed. The tetrazole precursor is prepared in one step by the Ugi-four component reaction. The reaction proceeds smoothly under mild conditions with high efficiency. This chemistry is simple, economical, and is believed to be the key step during the synthesis of significant pharmaceuticals.
The simple preparation of the title compounds succeeds in moderate to good yields via cyclocondensation of 4-substituted ethyl 4-alkoxy-2-oxobut-3-eneoates with 2-methyl or 2-benzylisothiourea.
The desulfitative dimethylamination of imidazolones (I) is achieved with DMF under optimized microwave conditions.
