Regiospecific synthesis of α-chloro- and α-fluoro-1,2-diones

α-Chloro-1,2-diones and α-fluoro-1,2-diones were prepared from the corresponding α-chloroaldimines by a sequence of reactions involving cyanation to α-cyanoenamines, α-halogenation to form α-chloro- or α-fluoroimidoyl cyanides and addition of organolithium reagents across the nitrile moiety, followed by acidic hydrolysis. All steps are straightforward and occur without side reactions finally leading to regiospecifically chlorinated and fluorinated 1,2-diones in good yields.     

Reactions of bromine-containing organozinc compounds derived from α,α-dibromo ketones with 2-arylmethylideneindan-1,3-diones and 5-arylmethylidene-2,2-dimethyl-1,3-dioxane-4,6-diones

Bromine-containing organozinc compounds generated from 1,1-dibromo-3,3-dimethylbutan-2-one reacted with 2-arylmethylideneindan-1,3-diones and 5-arylmethylidene-2,2-dimethyl-1,3-dioxane-4,6-diones to give 3-aryl-2-(2,2-dimethylpropanoyl)spiro[cyclopropane-1,2′-indan]-1′,3′-diones and 1-aryl-6,6-dimethyl-2-(2,2-dimethylpropanoyl)-5,7-dioxaspiro[2.5]octan-4,8-diones, respectively. Reactions of 2-arylmethylideneindan-1,3-diones with bromine-containing zinc enolates derived from 1-aryl-2,2-dibromopropan-1-ones and 2,2-dibromo-1,2,3,4-tetrahydronaphthalen-1-one resulted in the formation of 2-aroyl-3-aryl-2-methylspiro-[cyclopropane-1,2′-indan]-1′,3′-diones and 2,3: 8,9-dibenzo-12-phenyldispiro[4.0.5.1]dodecane-1,4,7-trione, respectively.     

A convenient route to azetidine-2,3-diones and cis-3β-amido azetidinones

The synthesis of 3β-amido azetidinones, 8a and 8b, via azetidine-2,3-diones is described.     

Synthesis and Structure of 3-Aryl-5-cyano-6-methylthio pyrimidine2,4-diones

Polarizedketenedithioacetalsl,(XY)C=C(SR)2(X,Y=CN,NO2,COOEt,CONH=,R=alkyl,benzyl).havebeenextensivelyusedasbuildingblocksinorganicsynthesisespeciallyinthepreparationofheterocycliccompounds''.Inanextensionofourrecentstudies'intheapplicationofketokete...     

Rational design and synthesis of some PPAR-γ agonists: Substituted benzylideneamino-benzylidene-thiazolidine-2,4-diones

The peroxisome proliferator activator receptor-γ (PPAR-γ) remained the most successful target for management of diabetes mellitus. The present work endeavors rational designing of some novel PPAR-γ agonists bearing benzylideneamino-benzylidene-thiazolidine-2,4-dione scaffold. The research involved virtual screening of 37 different molecules by molecular docking studies performed by Molecular Design Suite (MDS) into the ligand binding domain of PPAR-γ receptor to explore the binding affinity and conformations of the molecules. Eight compounds; TZD1, TZD-4, TZD-7, TZD-16, TZD-25, TZD-28, TZD-34, and TZD-37 demonstrated high affinity for PPAR-γ binding site. The following compounds were taken into the account and synthesized using a multi-step synthesis protocol. The purity of the synthesized compounds was ascertained by sophisticated analytical techniques such as IR, NMR, Mass and elemental analysis. The compounds were tested for glucose uptake assay by using 3T3-L1 cell lines, where all the candidates exhibited nearly similar potential for uptake of glucose into the lines as that of standard drug rosiglitazone. Three molecules; TZD-1, TZD-4, and TZD-34 showed most prominent activity over hyperglycemic control. This research opened new avenues for smart designing of molecules with high efficiency towards the management of hyperglycemia.     

One-pot Synthesis of 3-Aryl-1,5-bis（2-hydroxyaryl）pentane-1,5-diones

A simple method for the synthesis of 3-aryl-1,5-bis(2-hydroxyaryl)pentane-1,5-diones is developed by one-potreaction involving 2-hydroxyacetophenone and arylaldehyde in aqueous potassium hydroxide.     

Novel Fluorinated Spiro [Indole-indazolyl-thiazolidine]-2,4′-diones: Design and Synthesis

The reaction of indol-2,3-diones ( 1a–i ) with 5-aminoindazole ( 2 ) has resulted in the formation of hitherto unknown 3-(indazol-5-yl)iminoindol-2-ones ( 3a–i ) in quantitative yields which, on 1,3-dipolar cyclocondensation with mercaptoacetic acid ( 4 ), has afforded a series of new spiro heterocycles, 3′-(indazol-5-yl) spiro[3H, indol-3, 2′ -thiazolidine]-2,4′-diones* ( 5a–i ).     

Facile Synthesis of 3-Alkyl-5-methyloxazolidine-2,4-diones and N-Lactoyl-N,N′-dialkylureas

The reaction between aliphatic amines and propylene carbonate can be performed in solventless conditions under microwave irradiation, becoming nearly complete within 15 min of irradiation. Oxidation of the formed mixture of 2-hydroxyethylcarbamates gives 3,5-methylalkyl-oxazolidine-2,4-diones. These compounds can react further with aliphatic primary amines to give N-lactoylureas.

Three-component one-pot synthesis of fused uracils – pyrano[2,3-d]‐pyrimidine-2,4-diones

5-Arylidene-N,N-dimethylbarbituric acids undergo smooth hetero-Diels-Alder reactions with enol ethers to afford cis and trans diastereoisomers of 7-alkoxy-5-aryl-2H-pyrano[2,3-d]pyrimidine-2,4-diones in excellent yields (84–95%). Cycloadducts with cis-configuration were the major products. Three-component one-pot reactions of N,N-dimethylbarbituric acid, aromatic and heteroaromatic aldehydes, and enol ethers in the presence of piperidine gave uracils also in very good yields (87–95%). The structure of the cycloadducts is discussed in terms of configuration and preferred conformation. Correspondence: Aleksandra Pałasz, Department of Organic Chemistry, Jagiellonian University, Kraków, Poland.     

Synthesis of 9-aryl-3,4,6,7,9,10-hexahydroacridine-1,8(2Н,5Н)-diones

The reaction in a mixture of 1,3-cyclohexanedione (dimedone), arylaldehyde, and ammonium acetate at 160°C during 10–15 min in the absence of solvent leads to the formation of 9-aryl-3,4,6,7,9,10-hexahydroacridine-1,8(2H,5H)-diones. The structure of the products has been confirmed by IR and ¹H NMR spectroscopy data. Antimicrobial activity of the obtained compounds has been studied.

     

Alkyl 3-nitroacrylates: Synthesis and reactions with cyclohexane-1,3-diones and Meldrum’s acid

A modified procedure was proposed for the synthesis of alkyl 3-nitroacrylates by nitroiodination of alkyl acrylates and subsequent dehydroiodination of iodonitropropanoates with triethylamine. Alkyl 3-nitroacrylates reacted with cyclohexane-1,3-dione, dimedone, and Meldrum’s acid in the presence of N,N,N-tri-methylanilinium hydroxide (Rodionov’s catalyst) in anhydrous methanol to give the corresponding Michael adducts.     

Versatile synthesis of quaternary 1,3-oxazolidine-2,4-diones and their use in the preparation of α-hydroxyamides

A new approach to the synthesis of 1,3-oxazolidine-2,4-diones, via a two-step reaction sequence, starting from the readily available α-ketols and isocyanates, is reported. The condensation of the latter led to the key precursors 4-methylene-2-oxazolidinones, which are converted into the diones by an oxidative cleavage of the exocyclic double bond. Thus, 5,5-disubstituted 1,3-oxazolidine-2,4-diones can be accessed in good yields from the appropriate functionalized α-ketols. Moreover, two alternative routes are also described either by functionalization of 4-oxazolin-2-ones or by alkylation of the 1,3-oxazolidine-2,4-dione core previously prepared. Upon hydrolysis of the 1,3-oxazolidine-2,4-diones, a series of α-hydroxyamides bearing a quaternary stereocenter were obtained.     

Synthesis of Bicyclo[4.3.0]Non-3-ene-7,9-diones via Solventless Diels–Alder Methodology

Four novel bicyclo[4.3.0]non-3-ene-7,9-diones have been synthesized in moderate to good yields through a solventless Diels–Alder cycloaddition method and characterized. Atom economies after purification ranged from 21% to 32%, and E factors ranged from 2.7 to 3.7. All reaction products exhibited endo selectivity. Dienophiles with heteroatoms that contribute electrons to the π system exhibited faster reaction times than the carbocyclic analog. Hydrogen-bond donating ability in the diene had no noticeable effect on reaction times.

An Easy Approach to Prepare Naphtho [−2, 3-b] Furan-4, 9-diones

From the ethanol extract of the stem bark of Tabebuia cassinoide (Lam.) (Bignoniaceae), Rao and Kingston isolated two new quinones, 5 and 6, that showed activity in KB cell culture assay. The synthesis of these quinones were realized by two routes that would be amenable to relatively large-scale work.     

Thermolysis reactions of N-alkyl-N′-CBZ amino acid amides. A route to substituted imidazolidine-2,4-diones

Reaction of N-alkyl-N′-CBZ amino acid amides under microwave conditions in water and in the presence of an acid catalyst results in the formation of N-substituted imidazolidine-2,4-diones in good yields.     

Functionalization of Csp3–H Bond of Methyl Substituent in Quinaldine with 5-Arylfuran-2,3-diones

Russian Journal of Organic Chemistry - New effective method of direct functionalization of Сsp3–H bond in methyl substituent of quinaldine under the action of 5-arylfuran-2,3-diones was...     

1-Bromo-2,4-dihydro-1H-pyrazino[2,1-b]quinazoline-3,6-diones as α-bromoglycine templates

The title compounds behaved as α-bromoglycine templates. Radical substitutions and S_N1-type nucleophilic additions proceeded with retention of stereochemistry, while S_N2-type displacements occurred with net inversion of configuration. A homocoupling product was obtained in attempting a Stille cross-coupling reaction.     

Synthesis and spatial structure of methyl substituted 2-phenylpiperidine-4-spiro-5′-imidazolidine-2′,4′-diones

Piperidine-4-spiro-5-irnidazolidine-2, 4-diones have been synthesized from the appropriate methyl substituted 2 phenyl-4-hydroxypiperidines and 4-cyano-4-aminopiperidines by the Bucherer—Bergs and Strecker methods. The stereocheinical composition and spatial structure of the compounds synthesized have been established from¹H and¹³C NMR data.Moscow State Academy of Fine Chemical Technology, Moscow 117571. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 798–801, June, 1994. Original article submitted May 11, 1994.