Three-Component Spiro Heterocyclization of Pyrrolediones with Indan-1,3-dione and Acyclic Enamines

Ethyl 4,5-dioxo-2-phenyl-4,5-dihydro-1H-pynole-3-carboxylates reacted with indan-1,3-dione and 3-amino-1-phenylbut-2-en-1-one or 3-aminobut-2-enenitrile to give 3-benzoyl-2-methyl-2′,5-dioxo-5′-prienyl-1,1′,2′,5-tetrahydrospiro[indeno[1,2-b]pyridine-4,3′-pyrroles] and 2-methyl-2′,5-dioxo-5′-phenyl-1,1′,2′,5-tetrahydrospiro[indeno[1,2-b]pyridine-4,3′-pyrrole]-3-carbonitriles, respectively.

     

Pyrimidines. 24. Analogues and derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP)

Preparation of a number of derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP) including the 2-dialkylaminoalkylamino-, 2-hydroxyalkylamino-, 2-ethoxycarbonylamino- and 2-alkylaminocarbonyl-amino- groups substituted on the pyrimidine ring as well as preparation of 1-(alkylaminoalkyl)-4,6-dioxo-8-phenyl-2,3,4,6-tetrahydro-1H-pyrimido[1,2-α]pyrimidines and 3,5-dioxo-7-phenyl-1,2,3,5-tetrahydroimidazo-[1,2-α]pyrimidines with or without the bromo-substitution are reported.     

Isomeric Dioxodihydro-1H-Benzo[b]thiophenoindole Synthesis and Properties

The synthesis and properties of new heterocyclic systems are described: isomeric 2,3-dioxo-2,3-dihydro-1H-benzo[b]thiopheno[2,3-g]-, 1,2-dioxo-1,2-dihydro-1H-benzo[b]thiopheno[3,2-e]-, and 2,3-dioxo-2,3-dihydro-1H-benzo[b]thiopheno[2,3-f]indoles. The reduction of the latter to the corresponding unsubstituted benzo[b]thiophenoindoles depends on both the nature of the reducing agent and the reaction conditions.     

Chemistry of acyl(imidoyl)ketenes. 7. Synthesis and thermolysis of 5-aryl-4-quinoxalinyl-2,3-dihydrofuran-2,3-diones

3-Aryl-Z-2-aroylmethylidene-1,2-dihydroquinoxalines react with oxalyl chloride to form 3-aryl-2-(2-aryl-4,5-dioxo-4,5-dihydro-3-furyl)quinoxalines, whose thermal decarbonylation generate 5-aryl-2-3(arylquinoxalin-2-yl)-4-aroyl-3-aroyloxy-1H-pyrido[1,2-a]quinoxalin-1-ones. The crystal and molecular structures of one of them (Ar = Ph) were established by X-ray diffraction analysis.     

A novel oxamide rearrangement

An efficient, base-induced rearrangement of 2-[(1,2-dioxo-2-(methylamino)ethyl)phenylamino]benzoic acid methyl ester ( 7a ) to the isomeric 2-[(1,2-dioxo-2-(phenylamino)ethyl)methylamino]benzoic acid methyl ester ( 27a ) is described. This novel rearrangement must proceed through a spiro intermediate wherein benzoate is acting as a Michael receptor. When 2-[(1,2-dioxo-2-(methylamino)ethyl)methylamino]benzoic acid methyl ester ( 28 )-an oxamide which would produce a degenerate spiro intermediate — was subjected to rearrangement conditions, the product obtained was 1,3-dimethyl-2,4-(1H,3H)quinazolinedione ( 29 ). This latter transformation may have proceeded via a benzodiazepinetrione intermediate.     

Synthesis of the (Z) and (E) isomers of 1,2-diaryl-3-methyl-4,5-dioxo-3-pyrrolidinecarboxylic acid esters. Structural assignment by nmr and mass spectroscopy

Reaction of N-benzylideneaniline, 1a , with 3-methyl-2-oxobutanedioic acid diethyl ester, 2a , produced isomeric 3-methyl-4,5-dioxo-1,2-diphenyl-3-pyrrolidinecarboxylic acid ethyl esters, 3a and 3b . The higher melting isomer, 3a , was shown to have the (Z) configuration by nmr spectroscopy. The (Z) and (E) isomers of 3-methyl-4,5-dioxo-1,2-diphenyl-3-pyrrolidinecarboxylic acid methyl esters, 3c and 3d , were prepared from 1a and 3-methyl-2-oxobutanedioic acid dimethyl ester, 2b . The higher melting isomer, 3c , was shown to have the (Z) configuration. Similarly, N-benzylidene-p-toluidine, 1b , reacted with 2a to form (Z) and (E) isomers of 3-methyl-4,5-dioxo-1-(4-methylphenyl)-2-phenyl-3-pyrrolidinecarboxlic acid ethyl esters, 3e and 3f . Assignment of the ¹³C carbonyl carbon nmr chemical shift was made by preparing 2-methyl-3-oxobutanedioic-1-¹³C acid diethyl ester, 4 , and from it the corresponding (Z) and (E) isomers of 3-methyl-4,5-dioxo-1,2-diphenyl-3-pyrrolidinecarboxylic ¹³C acid ester, 5a and 5b . The mass spectra of the (Z) isomers exhibit prominent ions corresponding to the masses of the Schiff bases used to make them, and ions corresponding to the loss of ArNCOCO from the parent ion. The (E) isomers 3b, 3d and 5b exhibit a prominent ion of mass 264; 3f gives mass 278, corresponding to the loss of the carboalkoxy group.     

A simple synthesis of 1-phenothiazineethanolamines: Potential antimalarials

Two routes for the synthesis of the 1-phenothiazineethanolamine (4) starting from 1,2-dioxo-1,2-dihydropyrrolo[3,2,1-kl]phenothiazine are described.     

Reaction of 2-dimethylaminomethylene-1,3-diones with dinucleophiles. V. Synthesis of 5-acyl-1,2-dihydro-2-oxo-3-pyridinecarbonitriles and 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarboxamides

The reaction of open-chain sym-2-dimethylaminomethylene-1,3-diones Ia-d with sodium cyanoacetamide gave, generally in good yields, 6-substituted 5-acyl-1,2-dihydro-2-oxo-3-pyridinecarbonitriles IIa-d, whereas cyclohexane sym-2-dimethylaminomethylene-1,3-diones Ie-h afforded in general a mixture of 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarbonitriles and 5,6,7,8-tetrahydro-2,5-dioxo-2H-1-benzopyran-3-carboxamides, the latter being isolated in two cases. The reaction of Ie-h with cyanoacetamide in refluxing anhydrous ethanol gave 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarboxamides IIIe-h in excellent yields, whereas Ia-d did not react with the exception of Ia which afforded in good yield 3-pyridinecarboxamide IlIa. Other 3-pyridine-carboxamides were obtained by partial hydrolysis of nitriles IIb,d. 3-Pyridine and 3-quinoline carboxamides were hydrolyzed in satisfactory yields with hydrochloric acid to the corresponding carboxylic acids, which were decarboxylated in good yields to 5-acyl-2(1H)-pyridinones and 7,8-dihydro-2,5(1H,6H)-quinolinediones, respectively, by reflux in quinoline containing a catalytic amount of copper powder.     

Five-membered 2,3-dioxo heterocycles: LXX. Spiro heterocyclization of 1H-pyrrole-2,3-diones by the action of 1,5-binucleophiles. Crystalline and molecular structure of ethyl 1′-benzyl-7-methoxy-3,3-dimethyl-1,2′-dioxo-5′-phenyl-1′,2,2′,3,4,10-hexahydro-1H-spiro[acridine-9,3′-pyrrole]-4′-carboxylate

Ethyl 1-alkyl-4,5-dioxo-2-phenyl-4,5-dihydro-1H-pyrrole-3-carboxylates reacted with 3-arylamino-5,5-dimethylcyclohex-2-en-1-ones as carbon-centered 1,5-binucleophiles to give the corresponding substituted ethyl 1′-alkyl-3,3-dimethyl-1,2′-dioxo-5′-phenyl-1′,2,2′,3,4,10-hexahydro-1H-spiro[acridine-9,3′-pyrrole]-4′-carboxylates whose structure was proved by X-ray analysis.     

3-Methylidene-2,4-dioxo-4-pentafluorophenylbutanoates in the Synthesis of Heterocycles

3-Ethoxy- and 3-arylaminomethylidene-2,4-dioxo-4-pentafluorophenylbutanoates undergo cyclization by the action of hydrazine hydrate and phenylhydrazine to give ethyl 4-pentafluorobenzoylpyrazole-5-carboxylates. The reaction of 3-ethoxymethylidene-2,4-dioxo-4-pentafluorophenylbutanoate with o-phenylene-diamine leads to formation of 3-[2-(2-aminophenylamino)-1-pentafluorobenzoylethenyl]-1,2-dihydroquinoxa-lin-2-one. 3-Arylaminomethylidene-2,4-dioxo-4-pentafluorophenylbutanoates react with o-phenylenediamine to afford 3-(1-aryl-5,6,7,8-tetrafluoro-4-oxo-1,4-dihydroquinolin-3-yl)-1,2-dihydroquinoxalin-2-ones and/or 3-(2-arylamino-1-pentafluorobenzoylethenyl)-1,2-dihydroquinoxalin-2-ones.     

Three-component reaction of methyl 2,4-dioxo-4-phenylbutanoate and methyl 2,4-dioxopentanoate with aromatic aldehydes and propane-1,2-diamine and chemical properties of the products

The reactions of methyl 2,4-dioxo-4-phenylbutanoate and methyl 2,4-dioxopentanoate with a mixture of an aromatic aldehyde and propane-1,2-diamine, depending on the initial reactant ratio, gave 4-acyl-1-(2-aminopropyl)-5-aryl-3-hydroxy-2,5-dihydro-1H-pyrrol-2-ones and 1,1′-(propane-1,2-diyl)bis(4-acetyl-3-hydroxy-5-phenyl-2,5-dihydro-1H-pyrrol-2-one). Reactions of substituted 1-(2-aminopropyl)-2,5-dihydro-1H-pyrrol-2-ones with aromatic amines and hydrazines were studied, and the structure of one of the products, 5-(2-aminopropyl)-3,4-diphenylpyrrolo[3,4-c]pyrazol-6-one, was proved by X-ray analysis.     

Conformational Energies in Organic Six-Membered Cyclic Sulfoxides

Ab initio Hartree–Fock calculations at the HF/6?31 G* level of theory for geometry optimization and the MP2/6?31 G*//HF/6?31 G* and B3LYP/6-311G(2df,p)//HF/6?31 G* levels for a single point total energy calculation are reported for the important energy-minimum conformations of 1-oxo-thiane (1), 1-oxo-1,2-dithiane (2), 1-oxo-1,3-dithiane (3), 1-oxo-1,4-dithiane (4), 1,2-dioxo-1,2-dithiane (5), 1,3-dioxo-1,3-dithiane (6), and 1,4-dioxo-1,4-dithiane (7). According to the MP2/6-31G*//HF/6-31G* calculations, while the axial conformations of compounds 1, 2, and 4 are more stable than the equatorial forms by 6.0, 20.0, and 9.9 kJ mol^?1, respectively, the equatorial geometry of 3 is 3.0 kJ mol^?1 more stable than the axial form. The diaxial conformations of 5 and 7 are calculated to have similar energies, but the diaxial form of 6 is about 43 kJ mol^?1 less stable than that of 5 or 7.     

Synthesis of 9-Deoxynanaomycin,a Methyl Ester via 1,2-Ketone Transposition

The title compound, methyl trans 1-methyl-5,10-dioxo-3,4,5,10-tetrahydro-1H-naphthol[2,3-c] pyran-3-yl-acetate has been synthesised using the key intermediate, 1-(1,4-dimethoxy-2-naphthyl)-2-oxo-4-acetoxybutane, prepared through 1,2-ketone transposition of the 1-(1,4-dimethoxy-2-naphthyl)-4-acetoxy-1-butanone.     

Reaktionen von o-Chinonen mit Aminen und Proteinen. 4. Mitteilung. 7a-Methyl-5,6-dioxo-5,6,7,7a-tetrahydroindol-Derivate aus 4-Methylbrenzcatechin und Enaminen

Reactions of o-Quinones with Amines and Proteins. 7a-Methyl-5,6,7,7a-tetrahysroindole Derivatives from 4-Methylcatechol and Enamines Methyl l-[2′-(methoxycarbonyl)ethyl]-7a-methyl-5,6-dioxo-5.6.7,7a-tetrahydro-indole-3-carboxylate ( 1 ) was isolated after the oxidation of 4-methylcatechol with silver ( 1 ) oxide in the presence of b?-alanine methyl ester in glacial acetic acid. The formation of 1 requires in situ dehydrogenation of the b?-aminocarboxylate and addition of the resulting enamine to 4-methyl-1,2-benzoquinone. Reaction of ethyl 3-(phenylamino)crotonate with 4-methyl-1,2-benzoquinone afforded ethyl 2,7a-dimethyl-5,6-dioxo-1-phenyl-5,6,7,7a-tetrahydroindole-3-carboxylate ( 6 ). Despite the fact that the yields are low, the addition of enamines to o-quinones represents an interesting novel extension of the Nenitzescu-reaction which is well known in the p-quinone series. Compound 1 may be considered as a novel model for the crosslinking of proteins by o-quinones. Formation of 1 was, however, not observed under physiological conditions.     

Synthesis and structure of novel 1,2-dihydro-phthalazine containing betaines

1,2-Dihydro-2-(4,5-dihydroimidazol-2yl)phthalazin-1-ol 1 reacts exothermically with dialkyl acetylenedicarboxylates to give 3-[2-(4,5-dihydro-1H-imidazol-3-iurn-2-yl)-1,2-dihydro-1-phthalazin]-1,4-dialkoxy-1,4-dioxo-2-buten-2-olates 7 and 8 . Enolic ester compounds underwent further transesterification reactions with formation of the betaines 9 and 10 . The unequivocal structural assignement of these compounds was achieved by spectroscopic ¹H and ¹³C nmr methods as well as X-ray analysis of 7 .     

Combining a Click–Multicomponent Reaction: One-Pot Synthesis of 1,2,3-Triazol-4-ylmethyl 3-Amino-5,10-dihydro-5,10-dioxo-1H-pyrazolo[1,2-b]phthalazine-2-carboxylate Derivatives

(1,2,3-Triazol-4-yl)methyl-3-amino-5,10-dihydro-5,10-dioxo-1H-pyrazolo[1,2-b]phthalazine-2-carboxylate derivatives were synthesized by a four-component, one-pot condensation reaction of benzaldehyde derivatives, an active methylene compound (prop-2-ynyl-2-cyanoacetate), azides, and phthalhydrazide in the presence of Cu(OAc)₂/sodium ascorbate as catalysts and 1-methyl-1H-imidazolium trifluoroacetate ([Hmim]TFA) as an ionic liquid medium in good to excellent yields.     

A reaction of 6-bromo-1,2-naphthoquinone with tri(<Emphasis Type="Italic">n</Emphasis>-butyl)phosphine: A convenient route to phosphorus-containing 1,2-naphthoquinones and 1,2-dihydroxynaphthalenes

A reaction of 6-bromo-1,2-naphthoquinone with tri(n-butyl)phosphine gave 2-hydroxy-4-tri(n-butyl)phosphonionaphth-1-olate (betaine with the P—C bond). When treated with bromine, this betaine changed into (6-bromo-1,2-dihydroxy-4-naphthyl)tri(n-butyl)phosphonium bromide and (6-bromo-1,2-dioxo-1,2-dihydro-4-naphthyl)tri(n-butyl)phosphonium bromide in the ratio ∼1: 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 534–536, March, 2007.     

A reinvestigation of the synthesis of 3H-[1,2]diazepino[5,6-b]indoles. The synthesis of pyrido[4,3-b]indoles

Recently reported [1] syntheses of 6-methyl-1,2,4,5-tetrahydro-1,4-dioxo-3H[1,2]diazepino[5,6-b]indole ( 5 ) and 4-hydroxy-6-methyl-3H[1,2]diazepino[5,6-b]indole ( 12 ) were reinvestigated and shown to be in error. The correct assignments for these respective structures are 3-amino-1,9-dihydro-9-methyl-2H-pyrido[4,3-b]indol-2,4(3H)-dione ( 6 ) and 3-amino-3,9-dihydro-9-methyl-2H-pyrido[4,3-b]indol-2-one ( 13 ). Condensation of 6 and 13 with p-nitrobenzaldehyde produced benzylidene derivatives, which confirmed the presence of the amino groups.     

Reversible cyclization of N-(3-hydroxy-1-alkenyl)pyridinium salts to pyridooxazines

Partially hydrogenated pyrido[2,1-b][1,3]oxazine, cyclopenta[d]pyrido[2,1-b][1,3]oxazine and pyrido[1,2-a]-[3,1]benzoxazine ring systems were easily formed in the reaction of 3-hydroxy-2-(2-hydroxy-1,3-dioxo-2-indanyl)-2-alken-1-one derivatives with tosyl chloride and pyridine bases. A facile interconversion between pyridooxazines and the corresponding pyridinium salts was also realized.     

5,6-Dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepine-4,4-diacetic acid diethyl ester,an useful synthon for the synthesis of new polycyclic nitrogen systems of pharmacological interest

This report describes the synthesis of derivatives of two nitrogen tetracyclic ring systems, respectively 9H,11H-pyrimido[4,3-c]pyrrolo[1,2-a][1,4]benzodiazepine and spiro[piperidine-4,4′-[4H]pyrrolo[1,2-a][1,4]-benzodiazepine], by the use of the diethyl ester of 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepine-4,4-diacetic acid as a synthon. This compound was obtained by condensation of 1-(2-aminomethylphenyl)-1H-pyrrole with diethyl 1,3-acetonedicarboxylate in acid medium. Pyrimidopyrrolobenzodiazepine derivatives were obtained by treating either the pyrrolobenzodiazepine 4,4-diacetate or the related 4-methyl-4-acetate with phenylisocyanate in boiling diethyl ether in the presence of sodium metal. The structure of 12,13-dihydro-11,13-dioxo-12-phenyl-9H,11H-pyrimido[4,3-c]pyrrolo[1,2-a][1,4]benzodiazepine, a product formed by loss of an acetate unit when 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepine-4,4-diacetate, sodium metal and phenyl-isocyanate reacted in boiling xylene, was proved by catalytic reduction to 11,13-dioxo-12-phenyl-12,13,14,14a-tetrahydro-9H,11H-pyrimido[4,3-c]pyrrolo[1,2-a][1,4]benzodiazepine, which was synthesized by unambiguous pathway via 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepine-4-acetate. The 2,6-dioxospiro[piperidine-4,4′-[4H]pyrrolo[1,2-a][1,4]benzodiazepine] derivatives were synthesized from the N-BOC derivative of 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepine-4,4-diacetic acid diethyl ester, by hydrolysis followed by treatment with 2 equivalents of 1,1′-carbonyldiimidazole (CDI) and then with aniline or benzylamine. Removal of BOC from the N-phenyl-2,6-dioxopiperidine derivative was obtained by heating the related spiroderivative in toluene in the presence of p-toluenesulphonic acid. Similar reaction failed when the N-benzyl-2,6-dioxopiperidine analog was used as substrate.