Features of reactions of polyfluorinated ethyl 4-oxo-2-pnenyl-4H-chromene-3-carboxylates with N-nucleophiles

Ethyl 5,6,7,8-tetrafluoro-4-oxo-2-phenyl-4H-chromene-3-carboxylate in reactions with primary amines is characterized by a chromone-coumarin rearrangement affording 3-[amino(phenyl)methylene]-6,7,8-trifluoro-2H-chromene-2,4(3H)-diones, and ethyl 4-oxo-2-phenyl-5,6,7,8-tetrafluoro-4H-chromene-3-carboxylate characteristically adds the amine at the C² site of the flavone furnishing 3-amino-3-phenyl-2-(2,3,4,5-tetrafluoro-6-hydroxybenzoyl)acrylates which depending on the substituent at the amino group are capable of intramolecular cyclization into 3-[(alkylamino)(phenyl)methylene]-5,6,7,8-tetrafluoro-2H-chromene-2,4(3H)-dione or in the case of benzylamine substituent, into ethyl 1-benzyl-5-hydroxy-4-oxo-2-phenyl-6,7,8-trifluoro-1,4-dihydroquinoline-3-carboxylate. The main process in the reaction of tri- and tetrafluoroflavones with secondary amine (1-methylpiperazine) is the nucleophilic substitution at the C⁷ of flavone. In the reaction with 1,2-phenylenediamine 3-[(2-aminophenyl)amino]-3-phenyl-2-(2,3,4,5-tetrafluoro-6-hydroxybenzoyl)acrylate was obtained from tetrafluoroflavone and 1H-benzimidazol-2-yl(3,4,5-trifluoro-2-hydroxyphenyl)methanone, from trifluoroflavone.     

Fluorocontaining 1,3-Dicarbonyl Compounds in the Synthesis of Pyrimidine Derivatives

Hexafluoroacetylacetone reacts with urea (thiourea) to yield respectively 4,6-bis(hydroxy)-4,6-bis(trifluoromethyl)hexahydropyrimidin-2-one(thione). The dehydration of the products and also reaction of nonsymmetrical fluoroalkyl-containing 1,3-diketones with urea (thiourea) afford substituted pyrimidines. The condensation of fluorinated 3-oxoesters and 1,3-diketones with benzaldehyde and urea (thiourea) results in 5-alkoxycarbonyl(acyl)-4-hydroxy-2-oxo(thioxo)-6-phenyl-4-fluoroalkylhexahydropyrimidines that on dehydration furnish 5-alkoxycarbonyl(acyl)-2-oxo(thioxo)-4-phenyl-6-fluoroalkyltetrahydropyrimidines. Ethyl 7-nonafluorobutyl-5-phenyl-2,3-dihydrothiazolo[3,2-a]pyrimidine-6-carboxylate hydrobromide forms in reaction of dibromoethane with ethyl ether of 2-thioxo-4-phenyl-6-nonafluorobutyltetrahydropyrimidine.     

Iodine catalyzed one-pot multi-component reaction to CF3-containing spiro[indene-2,3′-piperidine] derivatives

In the presence of a catalytic amount of molecular iodine (0.1 equiv.), the one-pot multi-component reaction of ethyl trifluoroacetoacetate 1, indan-1,3-dione 2, ammonium acetate 3 and aromatic aldehyde 4 mainly gave the ethyl-6′-hydroxy-1,3-dioxo-2′,4′-diaryl-6′-(trifluoromethyl)-1,3-dihydrospiro[indene-2,3′-piperidine]-5′-carboxylate derivatives 5, along with the minor product 2-trifluoromethyl-2,3,4,5-tetrahydro-1H-indeno[1,2-b]pyridine derivatives 6. A plausible reaction mechanism for the formation of 5, 6 was presented. The structures of compounds 5, 6 were fully confirmed by ¹H NMR, ¹⁹F NMR, MS, IR spectroscopies and elemental analysis or high resolution mass spectra (HRMS). Meanwhile, the representative 5a and 6h were further confirmed by XRD analysis.     

Novel,Simple, and Efficient Synthesis of 3-(2-(5-(Benzylideneamino)-3-phenyl-1H-pyrazol-1-yl)thiazol-4-yl)-4-hydroxy-6-methyl-2H-pyran-2-one Derivatives via a One-Pot,Four-Component Condensation Reaction

The synthesis of 3-(2-(5-(benzylideneamino)-3-phenyl-1H-pyrazol-1-yl)thiazol-4-yl)-4-hydroxy-6-methyl-2H-pyran-2-one derivatives was achieved through a one-pot, four-component reaction involving condensation of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, thiosemicarbazide, phenacylcyanaide, and various aryl aldehydes in dry alcohol and few drops of acetic acid under reflux condition. This four-component reaction has some advantages such as ease of handling, good yields, and easy workup. All structures of newly prepared compounds were confirmed by analytical and spectral data.     

Convenient one-pot synthesis of fluorinated DHPs derivatives and their further transformations

One-pot four-component reactions of aromatic aldehyde, Meldrum’s acid, ethyl-4,4,4-trifluoro-1,3-dioxobutanoate, and ammonium acetate afford ethyl 2-hydroxy-6-oxo-4-aryl-2-(trifluoromethyl)piperidine-3-carboxylate in good yields. The one-pot four-component process consists of an initial Michael addition, and a subsequent intramolecular cyclization. The effect of solvents on the reaction efficiency and yield is briefly investigated. The structure of product is further confirmed by XRD analysis. Meanwhile, the further transformation of hemi-aminal moiety to the corresponding dehydrated product is also achieved under the mild reaction conditions. The possible mechanism for the formation of product is presented.     

Condensation of Stereoisomeric 2-Acetyl-2,3-diphenyloxiranes with Ethyl Trifluoroacetate

The reaction of E-2-acetyl-2,3-diphenyloxirane with ethyl trifluoroacetate in the presence of sodium isopropoxide leads to 3-hydroxy-2,3-diphenyl-6-trifluoromethyl-2,3-dihydro-4H-pyran-4-one. Under the same conditions Z-acetyloxirane forms 3-hydroxy-2-phenyl-5-trifluoromethylfuran as a result of retroaldol cleavage of the initial cyclocondensation product.     

Synthesis and reactions of 3-(3-ethoxycarbonyl-1-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-4-yl)propenic acid

The reaction of ethyl 4-formyl-1-phenyl-1H-pyrazole-3-carboxylate with the malonic acid led to the formation (2E)-3-(3-ethoxycarbonyl-1-phenyl-1H-pyrazol-4-yl)propenic acid. In reactions of this acid chloride with 4-amino-5-aryl(hetaryl)-4H-1,2,4-triazole-3-thiols were obtained ethyl 4-[(E)-2-{3-aryl(hetaryl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl}ethenyl]-1-phenyl-1H-pyrazoe-3-carboxylates, with 5-aryltetrazoles, ethyl 4-[(E)-2-(5-aryl-1,3,4-oxadiazol-2-yl)-ethenyl]-1-phenyl-1H-pyrazole-3-carboxylates, with 1-(2-hydroxy-3,5-dimethylphenyl) followed by the Baker-Venkataraman rearrangement and the cyclization, ethyl 4-[(E)-2-(6,8-dimethyl-4-oxo-4Hchromen-2-yl)ethenyl]-1-phenyl-1H-pyrazole-3-carboxylate.     

Novel sequence of two base-catalyzed 1,3 proton shifts and [1,2] Wittig rearrangement in the synthesis of 2,4-bis-(trifluoromethyl)-6-phenylpyridine

The reaction of 1,1,1,5,5,5-hexafluoro-2,4-pentanedione with (R)-phenylglycinol was found to proceed via intermediate formation of (R, 4E, 6Z)-5,7-bis-(trifluoromethyl)-2,3-dihydro-3-phenyl-1,4-oxazepine which further underwent a base-catalyzed 1,3-proton shift reaction followed by [1,2] Wittig rearrangement giving rise to 2,4-bis-(trifluoromethyl)-6-phenylpyridine.     

Synthesis of 1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide

The reaction of methyl 2-bromo-6-(trifluoromethyl)-3-pyridinecarboxylate ( 1 ) with methanesulfonamide gave methyl 2-[(methylsulfonyl)amino]-6-(trifluoromethyl)-3-pyridine-carboxylate ( 2 ). Alkylation of compound 2 with methyl iodide followed by cyclization of the resulting methyl 2-[methyl(methylsulfonyl)amino]-6-(trifluoromethyl)-3-pyridinecarboxylate ( 3 ) yielded 1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide ( 4 ). The reaction of compound 4 with α,2,4-trichlorotoluene, methyl bromopropionate, methyl iodide, 3-trifluoromethylphenyl isocyanate, phenyl isocyanate and 2,4-dichloro-5-(2-propynyloxy)phenyl isothiocyanate gave, respectively, 4-[(2,4-dichlorophenyl)methoxy]-1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazine 2,2-dioxide ( 5 ), methyl 2-[[1-methyl-2,2-dioxido-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4-yl]oxy]propanoate ( 6 ), 1,3,3-trimethyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide ( 7 ), 4-hydroxy-1-methyl-7-(trifluoromethyl)-N-[3-(trifluoromethyl)phenyl]-1H-pyrido[2,3-c][1,2]thiazine-3-carboxamide 2,2-dioxide ( 8 ), 4-hydroxy-1-methyl-7-(trifluoromethyl)-N-phenyl-1H-pyrido[2,3-c][1,2]thiazine-3-carboxamide 2,2-dioxide ( 9 ) and N-[2,4-dichloro-5-(2-propynyloxy)phenyl]-4-hydroxy-1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2] thiazine-3-carboxamide 2,2-dioxide ( 10 ).     

BCL-2选择性抑制剂——ABT-199的合成工艺改进

以3,3-二甲基环己酮(2)为原料,经5步反应制得中间体1-氯-4-［2-(氯甲基)-5,5-二甲基环己基-1-烯］苯（5）;以5-溴-7-氮杂吲哚为原料,经3步反应制得制得5-羟基-1-三异丙基硅基-7-氮杂吲哚（8）; 8与4-［3-氟-4-(甲氧基羰基)苯基］哌嗪-1-甲酸叔丁酯（9）经取代反应制得4-｛3-［(7-氮杂吲哚)氧］-4-(甲氧基羰基)苯基｝哌嗪-1-甲酸叔丁酯（10）;10脱保护后与5进行S_N2取代反应,所得中间体与3-硝基-4-｛［（四氢-2H-吡喃-4-基)甲基］氨基｝苯磺酰胺经缩合反应合成了BCL-2选择性抑制剂ABT-199,总收率28.4%,其结构经¹H NMR和ESI-MS确证。     

Five-membered dioxoheterocycles: XCIX. Reaction of 1-aryl-4-aroyl-5-methoxycarbonyl-1H-pyrrole-2,3-diones with indoles. Crystal and molecular structure of substituted 2-(indol-3-yl)pyrrole

1-Aryl-4-aroyl-5-methoxycarbonyl-1H-pyrrole-2,3-diones react with indole and 2-methylindole with the formation of methyl 1-aryl-3-aroyl-4-hydroxy-2-(1H-indol-3-yl)-5-oxo-2,5-dihydro-1H-pyrrole-2-carboxylates. Crystal and molecular structure of methyl 3-benzoyl-4-hydroxy-2-(2-methyl-1H-indol-3-yl)-5-oxo-1-phenyl-2,5-dihydro-1H-pyrrole-2-carboxylate was examined.     

A facile synthetic route to 2-trifluoromethyl-substituted polyfunctionalized chromenes and chromones

A method for the preparation of methyl 4-hydroxy-2-(trifluoromethyl)-4H-chromenes-3-carboxylate derivatives 3a–j from readily available trifluoromethylated building block methyl (Z)-2-bromo-4,4,4-trifluoro-2-butenoate 1 was described. Treatment of 3a–j with Sarrett reagent in CH₂Cl₂ generated methyl 4-oxo-2-(trifluoromethyl)-chromene-3-carboxylate derivatives 4a–h with moderate to good yields, which can be converted to 2-trifluoromethyl-substituted multifunctional benzoxepins through cyclopropanation and Lewis acid-catalyzed ring opening.     

D-Glucosyl Kojic Acid Derivatives,Potential Precursors for the Cyclic Carboxylate Equivalents of Gaba Mimetic Agents

Abstract

Precursors for the cyclic carboxyl equivalents of γ-aminobutyric acid (GABA) were synthesized. 5-O-(2, 3, 4, 6-Tetra-O-acetyl-β-D-gluco-pyranosyl-2-[4-phenyl-1, 2, 3-triazol-1-yl)methyl]-4H-pyran-4-one could be prepared by the glucosidation of 2-chloromethyl-5-hydroxy-4H-pyran-4-one. Nucleophilic displacement of the chlorine with azide ion gave the corresponding azidodeoxy derivative that upon 1, 3-dipolar cycloaddition with phenylacetylene yielded the triazolyl derivative.     

The first application of 4-alkoxy-1,1,1-trifluoroalk-3-en-2-ones in a three-component condensation protocol for the synthesis of 3-acyl-4-aryl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2H-chromen-5(6H)-ones

The one-pot, simple and efficient three-component condensation protocol for the preparation of a series of twenty-five new 3-acyl-4-aryl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2H-chromen-5(6H)-ones, where aryl = Ph, 4-tolyl, 4-ClPh, 4-NO₂Ph and 4-CHOPh, and acyl = Ac, Bz, 4-FBz, furan-2-oyl, thien-2-oyl and naphth-1-oyl, employing 1,3-cyclohexanedione, five aryl aldehydes and for the first time, six 4-alkyl(aryl/heteroaryl)-4-methoxy-1,1,1-trifluoroalk-3-en-2-ones, is described. Yields in 15-75% were obtained when the MCRs were performed in the presence of a catalytic amount of triethylamine (25 mol%) and in ethanol as solvent under reflux for 16 h. A representative X-ray diffraction data for 3-acetyl-4-phenyl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2H-chromen-5(6H)-one is also showed.     

Reaction of 5-oxo-2-phenyl-4,4-bis(trifluoromethyl)-4,5-dihydro-1,3,2-benzodioxaphosphepine with chloral. The synthesis and spatial structure of 5-carbaphosphatrane containing a four-membered ring

Phosphorylation of 2-hydroxyphenyl 2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl ketone with dichloro(phenyl)phosphine gave 5-oxo-2-phenyl-4,4-bis(trifluoromethyl)-4,5-di-hydro-1,3,2-benzodioxaphosphepine. Heating of the latter initiated an intramolecular interaction of the P atom with the carbonyl group. Hydrolysis of the intermediate product yielded 3-hydroxy-2-oxo-2-phenyl-3-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]-2,3-di-hydro-1,2λ⁵-benzo[d]oxaphosphole. The reaction was highly stereoselective (P_RC_S/P_SC_R). The reaction of the starting phosphepine with chloral proceeded highly stereoselectively (P_RC_SC_S/P_SC_RC_R) to give a 5-carbaphosphatrane derivative containing a four-membered ring, namely, 1-phenyl-3-trichloromethyl-10,10-bis(trifluoromethyl)-6,7-benzo-2,4,8,9-tetraoxa-1λ⁵-phosphatricyclo[3.3.2.0¹,⁵]decene. The trigonal bipyramid of the 5-carbaphosphatrane derivative is made up of the equatorial O atoms and the apical C atoms.     

Five-membered 2,3-dioxo heterocycles: XCIII. Spiro heterocyclization of 4,5-diaroyl-1H-pyrrole-2,3-diones with acyclic enamine. Crystalline and molecular structure of substituted 1,7-diazaspiro[4.4]nonane

4,5-Diaroyl-1-aryl-1H-pyrrole-2,3-diones reacted with ethyl 3-amino-3-phenylprop-2-enoate to give ethyl 4-aroyl-1,6-diaryl-3-hydroxy-2-oxo-8-phenyl-1,7-diazaspiro[4.4]nona-3,6,8-triene-9-carboxylates. The crystalline and molecular structures of ethyl 4-benzoyl-3-hydroxy-1-(4-methylphenyl)-2-oxo-6,8-diphenyl-1,7-diazaspiro[4.4]nona-3,6,8-triene-9-carboxylate were determined by X-ray analysis.     

Design, synthesis, and biological evaluation of a library of 1-(2-thiazolyl)-5-(trifluoromethyl)pyrazole-4-carboxamides

A library of 422 1-(2-thiazolyl)-5-(trifluoromethyl)pyrazole-4-carboxamides was prepared in five steps using solution-phase chemistry. The first step in the synthesis was the reaction of ethyl 2-ethoxymethylene-3-oxo-4,4,4-trifluorobutanoate with thiosemicarbazide, which is reported in the literature to afford a 1:1 mixture of ethyl 1-thiocarbamoyl-5-(trifluoromethyl)pyrazole-4-carboxylate and ethyl 1-thiocarbamoyl-3-(trifluoromethyl)pyrazole-4-carboxylate. We reassigned the structure of the product to be a single compound, ethyl 5-hydroxy-1-thiocarbamoyl-5-(trifluoromethyl)-4,5-dihydro-1H-pyrazole-4-carboxylate. This common intermediate was diversified by reaction with 17 alpha-bromoketones affording, in two steps, 17 1-(2-thiazolyl)-5-(trifluoromethyl)pyrazole-4-carboxylic acids. Scavenger resins were used to facilitate formation and purification of up to 27 amides from each of these acids in the last step. In addition, the Curtius reaction was applied to 12 of the acids followed by quenching with alcohols to afford a 108-member carbamate library. Certain compounds in the two libraries were toxic to C. elegans.     

Trifluoroacetylation of ethyl 2,4-dioxopentanoate. The first synthesis of 4-oxo-6-(trifluoromethyl)-4<Emphasis Type="Italic">H</Emphasis>-pyran-2-carboxylic acid and its derivatives

Condensation of ethyl 2,4-dioxopentanoate with ethyl trifluoroacetate in the presence of NaOEt leads to ethyl 4-oxo-6-(trifluoromethyl)-4H-pyran-2-carboxylate, from which the corresponding acid and its amide, as well as 4-hydroxy-6-(trifluoromethyl)pyridine-2-carboxamide were obtained. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 537–538, March, 2007.     

Domino reaction of 3-nitro-2-(trifluoromethyl)-2H-chromenes with 2-(1-phenylalkylidene)malononitriles: synthesis of functionalized 6-(trifluoromethyl)-6H-dibenzo[b,d]pyrans and a rare case of [1,5] sigmatropic shift of the nitro group

A variety of functionalized 6-(trifluoromethyl)-6H-dibenzo[b,d]pyrans were easily synthesized in good yields under mild conditions by a domino reaction of 3-nitro-2-(trifluoromethyl)-2H-chromenes with 2-(1-phenylethylidene)- and 2-(1-phenylpropylidene)malononitriles. In the latter case, intermediate 7-amino-10-methyl-10-nitro-9-phenyl-6-(trifluoromethyl)-10,10a-dihydro-6H-benzo[c]chromene-8-carbonitriles were isolated as a result of a rare [1,5] sigmatropic shift of the nitro group.     

Synthesis of 5-(trifluoromethyl)cyclohexane-1,3-dione and 3-amino-5-(trifluoromethyl)cyclohex-2-en-1-one: new trifluoromethyl building block

A simple synthesis of 5-(trifluoromethyl)cyclohexane-1,3-dione and 3-amino-5-(trifluoromethyl)cyclohex-2-en-1-one from the sodium salt of methyl or ethyl-4-hydroxy-2-oxo-6-(trifluoromethyl)cyclohex-3-en-1-oate is demonstrated. The compounds represent highly functionalized reactive intermediates for the synthesis of organic and heterocyclic compounds containing a trifluoromethyl group.