Reaction of 2-(2-oxo-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-indol-3-ylidene)acetic acid esters with benzene-1,2-diamine and 2-aminobenzenethiol

2-(2-Oxo-2,3-dihydro-1H-indol-3-ylidene)acetic acid esters reacted with benzene-1,2-diamine or 2-aminobenzenethiol to give (2-oxo-2,3-dihydro-1H-indol-3-yl)-substituted 3,4-dihydroquinoxalin-2(1H)-ones or 2H-1,4-benzothiazin-3(4H)-ones.     

Transformations of <Emphasis Type="Italic">N</Emphasis>-(2-acylaryl)benzamides and their analogs under the Camps cyclization conditions

N-(2-Acylaryl)benzamides and analogous N-substituted furan-2-, thiophene-2-, and cyclopropane-carboxamides in the systems EtONa–EtOH, EtONa–THF, and t-BuOK–t-BuOH undergo Camps cyclization to 2-aryl-, 2-hetaryl-, and 2-cyclopropylquinolin-4(1H)-ones with high yields. The same substrates in the system t-BuOK (5 equiv)–THF are converted mainly to the corresponding N-(2-hydroxyaryl) amides as a result of oxidative transformation of the acyl fragment into hydroxy group.     

Reactions of vinyl 2,3-epoxypropyl ethers with 4,5-dihydro-1H-pyrazoles

Reactions of vinyl 2,3-epoxypropyl ether and 2-(vinyloxy)ethyl 2,3-epoxypropyl ether with 4,5-dihydro-1H-pyrazoles give, respectively, 3-vinyloxy-1-(4,5-dihydro-1H-pyrazol-1-yl)propan-2-ols and 3-(2-vinyloxyethoxy)-1-(4,5-dihydro-1H-pyrazol-1-yl)propan-2-ols in 70–91% yield.     

Hetero-diels–alder reaction of 5-ylidene-4-sulfanylidene-1,3-thiazolidin-2-ones with <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-bis(methoxycarbonyl)-1,4-benzoquinone diimine

Hetero-Diels–Alder reaction of 5-(propan-2-ylidene)-4-sulfanylidene-1,3-thiazolidin-2-one with N,N′-bis(methoxycarbonyl)-1,4-benzoquinone diimine in boiling toluene afforded 87% of dimethyl 9,9-dimethyl-2-oxo-8a,9-dihydro-2H-thiochromeno[2,3-d][1,3]thiazole-5,8(3H,4aH)-diylidenedicarbamate. Analogous reactions of 5-benzylidene-, 5-{[4-(dimethylamino)phenyl]methylidene}-, and 5-[(2-hydroxyphenyl)-methylidene]-4-sulfanylidene-1,3-thiazolidin-2-ones led to the formation of the corresponding dimethyl 9-aryl-2-oxo-3,9-dihydro-2H-thiochromeno[2,3-d][1,3]thiazole-5,8-diyldicarbamates in 64–82% yield.     

Synthesis of 1-(1,3-dialkyl-2-oxo-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-imidazo-[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acids

Nitration of 2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one gave its 5-nitro derivative which was subjected to alkylation with dimethyl sulfate, diethyl sulfate, and benzyl(dimethyl)phenylammonium chloride. The resulting 1,3-dimethyl-, 1,3-diethyl-, and 1,3-dibenzyl-5-nitro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones were reduced to the corresponding 1,3-dialkyl-5-amino-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones, and the latter reacted with itaconic acid to produce 1-(1,3-dialkyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acids. 1-(2-Oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acid was obtained by analogous reaction with 5-amino-2,3-dihydro-1H-imidazo[4,5-b]-pyridin-2-one.     

Catalytic alkylation of cycloalkaneindoles and tetrahydro-γ-carboline with 9-oxiranylmethylcarbazole

Catalytic alkylation of substituted indoles such as cycloalkaneindoles and tetrahydro-γ-carboline using 9-oxiranylmethylcarbazole leads to the formation of 1-(carbazol-9-yl)-3-{dihydrocycloalkane[b]indol-4(1H)-yl}propan-2-ols and 1-(carbazol-9-yl)-3-{2,8-dimethyl-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl}propan-2-ol, conjugates containing 2-hydroxypropylene spacer.     

Synthesis and Characterization of Zn(II) Complexes of 2-(7-Bromo-2-oxo-5-phenyl-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-1,4-benzodiazepin-1-yl)acetohydrazide and Its Condensation Products with Pyruvic Acid and Isatin

The systems ZnCl₂–2-(7-bromo-2-oxo-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepin-1-yl)acetohydrazide (Hydr)–propan-2-ol, ZnCl₂–Hydr–pyruvic acid (HPv), and Zn(CH₃COO)₂–Hydr–isatin(HIz)–propan-2-ol were studied. Optimal synthesis conditions were determined, and the complexes [Zn(Hydr)₂Cl₂], [Zn(HydrHPv)₂Cl₂], and [Zn(HydrIz)₂] were isolated. The complexes were characterized by elemental analysis, thermogravimetry, IR spectroscopy, and mass spectrometry. The electrical conductivities of the complexes were measured. The local environment of the central atom in the coordination entity was determined by X-ray absorption spectroscopy.     

Reaction of Imidazoles and Triazoles with 1-(Benzotriazol-1-yl)-2-iodoethanone

Reactions of 2-methyl-1H-imidazole, 1H-benzimidazole, 4H-1,2,4-triazole, and 1H-benzotriazole with 1-(1H-benzotriazol-1-yl)-2-iodoethan-1-one in the absence of a base gave the corresponding N-mono- and N,N′-disubstituted derivatives. 4H-1,2,4-Triazole-3-thiol reacted with 1-(1H-benzotriazol-1-yl)-2-iodoethan-1- one to afford 1-([1,3]thiazolo[2,3-c][1,2,4]triazol-5-yl)-1H-benzotriazolium triiodide.     

Acylation of Fischer’s Base with Methyl Aroylpyruvates

Methyl (Z)-4-aryl-2-hydroxy-4-oxobut-2-enoates (methyl aroylpyruvates) reacted with 1,3,3-trimethyl- 2-methylidene-2,3-dihydro-1H-indole (Fischer’s base) to give (2Z,5E)-1-aryl-3-hydroxy-5-(1,3,3-trimethyl-2,3-dihydro-1H-indol-2-ylidene)pent-2-ene-1,4-diones.     

Azines and azoles: CXXV. New regioselective synthesis of 1-amino-6-methyluracils

Readily accessible 5-acetyl-4-hydroxy-3,6-dihydro-2H-1,3-thiazine-2,6-dione reacts with substituted hydrazines and carboxylic acid hydrazides under mild conditions to give the corresponding hydrazones. Under severe conditions (heating in boiling dimethylformamide) the reaction is accompanied by extrusion of COS with formation of substituted 1-amino-6-methyluracils. Reactions of 5-acetyl-4-hydroxy-3,6-dihydro-2H-1,3-thiazine-2,6-dione with monosubstituted alkyl-and arylhydrazines take different pathways, depending on the conditions. Heating of equimolar mixtures of the reactants in ethanol or propan-1-ol leads to the formation of 2-substituted 5-methyl-3-oxo-2,3-dihydro-1H-pyrazole-4-carboxamides rather than 1-amino-6-methyluracil derivatives.     

Synthesis of 1-[4-(1,3-diaryl-4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-5-yl)-2,3,5,6-tetrafluorophenyl]piperidin-4-ols and their acrylates

(4-Hydroxypiperidin-1-yl)tetra- and -octafluorochalcones reacted with phenylhydrazine in acetic acid to give mixtures of polyfluoro-1,3,5-triaryl-4,5-dihydro-1H-pyrazoles and their O-acetyl derivatives. Analogous reactions in ethanol afforded in satisfactory yields 1-[4-(1,3-diaryl-4,5-dihydro-1H-pyrazol-5-yl)-2,3,5,6-tetrafluorophenyl]piperidin-4-ols which were treated with acryloyl chloride to obtain the corresponding acrylates that are promising as monomers for the preparation of fluorescent films.     

Synthesis of carbamate derivatives of 2,3-dihydro-4<Emphasis Type="Italic">H</Emphasis>-1,4-benzoxazine

Alkylation of methyl 2-hydroxyphenylcarbamates with 1,2-dibromoethane in acetone in the presence of K₂CO₃ gave the corresponding methyl 6(7)-R-2,3-dihydro-4H-1,4-benzoxazine-4-carboxylate. Alkylation of methyl 2-hydroxyphenylcarbamates with chloromethyloxirane was accompanied by recyclization of the oxirane ring with formation of methyl 6(7)-R-3-hydroxymethyl-2,3-dihydro-4H-1,4-benzoxazine-4-carboxylates.     

Synthesis of substituted 2-(thiophen-2-yl)-1<Emphasis Type="Italic">H</Emphasis>-imidazol-1-ols

Substituted 2-(thiophen-2-yl)-1H-imidazol-1-ols were synthesized by cyclization of the corresponding α-thienyl nitrones in alkaline medium. α-Thienyl nitrones were obtained by reaction of N-(1-hydroxyimine-1-R-propan-2-yl)hydroxylamines with thiophene-2-carbaldehyde in methanol. At boiling α-thienyl nitrones in methanol in the presence of sodium methylate 5-aryl(hetaryl)-2-(thiophen-2-yl)-1H-imidazol-1-ols are formed chemoselectively.     

Five-membered 2,3-dioxo heterocycles: LII. Reactions of 5-aryl-4-(quinoxalin-2-yl)-2,3-dihydrofuran-2,3-diones with Schiff bases and dicyclohexylcarbodiimide. Crystalline and molecular structure of substituted 2-(4-oxo-3,4-dihydro-2<Emphasis Type="Italic">H</Emphasis>1,3-oxazin-5-yl)quinoxalines

Aroyl(quinoxalinyl)ketenes generated by thermolysis of 5-aryl-4-(quinoxalin-2-yl)-2,3-dihydrofuran-2,3-diones react with N-benzylideneanilines and N,N’-dicyclohexylcarbodiimide according to the [4+2]-cycloaddition pattern where the aroylketene acts as diene, and C=N component, as dienophile, to give 3-aryl-2-(2,3,6-triaryl- and 6-aryl-3-cyclohexyl-2-cyclohexylimino-4-oxo-3,4-dihydro-2H-1,3-oxazin-5-yl)quinoxalines. The structure of two cycloaddition products was proved by X-ray analysis.     

Oxidative trifluoroacetamidation of (1<Emphasis Type="Italic">E</Emphasis>,3<Emphasis Type="Italic">E</Emphasis>)-1,4-diphenylbuta-1,3-diene and 1,1,4,4-tetraphenylbuta-1,3-diene

Reactions of trifluoroacetamide with (1E,3E)-1,4-diphenylbuta-1,3-diene and 1,1,4,4-tetraphenylbuta-1,3-diene in the oxidative system t-BuOCl–NaI have been studied. The reaction with (1E,3E)-1,4-diphenylbuta-1,3-diene afforded three products, N,N′-(phenylmethylene)bis(trifluoroacetamide), 3-chloro-4-iodo- 2,5-diphenyl-1-(trifluoroacetyl)pyrrolidine, and trifluoro-N-[(3E)-2-hydroxy-1,4-diphenylbut-3-en-1-yl]acetamide, with a high overall yield. 1,1,4,4-Tetraphenylbuta-1,3-diene failed to react with trifluoroacetamide.     

Reaction of a stable silylene with tetrahydrofuran

Reduction of 1,3-di-tert-butyl-2,2-dichloro-2,3-dihydro-1H-1,3,2-diazasilole with metallic potassium gave, instead of a stable silylene, 1,3-di-tert-butyl-2,3-dihydro-1H-1,3,2λ²-diazasilylolene, a product of insertion of the latter into the carbon-oxygen bond of tetrahydrofuran, 1,4-di-tert-butyl-6-oxa-1,4-diaza-5-silaspiro[4,5]dec-2-ene.     

Chemistry of Acyl(imidoyl)ketenes: IX. Synthesis and Thermolysis of 3-Aroyl-8-chloro-1,2-dihydro-4<Emphasis Type="Italic">H</Emphasis>-pyrrolo[2,1-<Emphasis Type="Italic">c</Emphasis>][1,4]benzoxazine-1,2,4-triones

Reactions of 3-Z-aroylmethylene-6-chloro-3,4-dihydro-2H-1,4-benzoxazine-2-ones with oxalyl chloride afford 3-aroyl-8-chloro-1,2-dihydro-4H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones and Z-3-(2-aryl-2-chlorovinyl)-6-chloro-2H-1,4-benzoxazine-2-ones. Aroyl(imidoyl)ketenes generated by decarbonylation of pyrrolobenzoxazinetriones undergo dimerization through [4+2]-cycloaddition to form 4-aroyl-3-aroyloxy-2-(2-oxo-2H-1,4-benzoxazin-3-yl)-1H, 5H-pyrido[2,1-c][1,4]benzoxazine-1,5-diones.     

Functionalization of methyl 3-acetyl-5-[(methoxycarbonyl)amino]-2-methyl-1<Emphasis Type="Italic">H</Emphasis>-indole-1-carboxylate

Oxidative heterocyclization of methyl 3-{1-[2-(carbamoylhydrazinylidene)]ethyl}-2-methyl-5-[(methoxycarbonyl)amino]-1H-indole-1-carboxylate by the action of selenium dioxide in acetic acid and heating of the corresponding thiosemicarbazone in boiling acetic anhydride gave 1,2,3-selenadiazole and 2,3-dihydro-1,3,4-thiadiazole derivatives, respectively. Methyl 3-acetyl-2-methyl-5-[(methoxycarbonyl)amino]-1H-indole-1-carboxylate reacted with selenium dioxide in dioxane–water (30: 1) at 80?90°C to form methyl 5-[(methoxycarbonyl)amino]-2-methyl-3-(2-oxoacetyl)-1H-indole-1-carboxylate whose condensation with o-phenylenediamine afforded methyl 2-methyl-5-[(methoxycarbonyl)amino]-3-(quinoxalin-2-yl)-1H-indole-1-carboxylate.     

Synthesis of <Emphasis Type="Italic">O</Emphasis>-[2-hydroxy-3-(vinyloxy)propyl]oximes and <Emphasis Type="Italic">O</Emphasis>-[(2-methyl-1,3-dioxolan-4-yl)methyl]oximes

By oximes reaction with glycidyl vinyl ether O-[2-hydroxy-3-(vinyloxy)propyl]oximes of ketones and acetaldehyde were synthesized in 54–72% yield, and by acid catalysis the compounds were converted into O-[(2-methyl-1,3-dioxolan-4-yl)methyl]oximes in 61–88% yield.     

Two concurrent pathways of the reaction of pyrrolobenzoxazinetriones with cyclic alkoxyolefins. Synthesis of alkaloid-like pentacyclic 6/6/5/6/5- and 6/6/5/6/6-angularly fused heterocycles

3-Aroylpyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones reacted with 2,3-dihydrofuran and 3,4-dihydro-2H-pyran to give mixtures of the corresponding hetero-Diels–Alder and Michael addition products.