Acyloxy derivatives of trivalent phosphorus in amidoalkylation of hydrophosphoryl compounds

In order to model the previously suggested mechanism of the P-C bond formation via the Arbuzov reaction, we have studied the interaction of diethylacylphosphite (prepared beforehand as well as generated in situ from tetraethylpyrophosphite) with the in situ generated acyliminium cation. Various conditions of in situ generation of acylphosphite derivatives of P(III) from hydrophosphoryl compounds and acyliminium ions from N,N′-alkylidenebiscarbamates have been investigated: solvent nature, acid catalyst, and the reagents mixing order). The results obtained have confirmed the suggested mechanism of three-component reaction of amidoalkylation of hydrophosphoryl compounds with the formation of P-C bond via the Arbuzov reaction of in situ formed intermediates.     

Synthesis and nitration of <Emphasis Type="Italic">N,N</Emphasis>´-bis(3-R-furoxan-4-yl)methylenediamines

A Mannich reaction of 4-amino-3-R-furoxans with paraformaldehyde in 10% aqueous H₂SO₄ led to the high yields of N,N′-bis(3-R-furoxan-4-yl)methylenediamines, whose structure (using R = Me as an example) was confirmed by X-ray diffraction study. The N,N′-bis-(3-R-furoxan-4-yl)methylenediamines obtained were nitrated to N,N′-dinitro-N,N′-bis-(3-R-furoxan-4-yl)methylenediamines upon the action of 100% HNO₃ in acetic or trifluoroacetic anhydride.     

Synthesis and chemical transformations of silicon-containing derivatives ofN,N-dimethylhydrazine

Reactions of carbofunctional organosilicon compounds withN,N-dimethyl-N′-trimethylsilylhydrazine andN,N-dimethyl-N′,N′-bis(trimethylsilyl)hydrazine were studied. The composition and structure of the reaction products were found to be dependent on the reagent nature and the reaction conditions. 1,4-Dimethylamino-2,2,5,5-tetramethyl-1,4-diaza-2,5-disilacyclohexane, a first representative of a new type of 2,5-disilapiperazines, was synthesized. A scheme of its formation was proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 169–173, January, 1999.     

A modified bischler-napieralski reaction. Synthesis of 2,3,4,9- tetrahydro-1H-pyrido[3,4-B]indole derivatives and their base-catalyzed transformation to N-acetyl-N-[2-[1 -acetyl-2-[1 -(acetyloxy)-1-propenyl]- 1H-indol-3-yl]ethyl]acetamides

The treatment of N-[2-(1H-indol-3-yl)ethyl]alkanamide, 1 (1), with phosphorus oxychloride under controlled conditions gave l-alkyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-ol, 2 . The reaction of 2 with acetic anhydride or with methyl isocyanate at room temperature resulted in the formation of amido carbinol 3 and urea carbinol 7, respectively. The former was transformed into amido ester 4 by boiling acetic anhydride. When the reaction of 3 with acetic anhydride was carried out in the presence of excess triethylamine at 105°, C-N bond cleavage of the tetrahydropyridine ring took place with concurrent bis(N-acetylation) to give the enol ester derivative 5 . The structures of all compounds are consistent with chemical and spectral evidence.     

Synthesis and properties of <Emphasis Type="Italic">N</Emphasis>-[2,2-bis(2,4-dihydroxyaryl)ethyl]-<Emphasis Type="Italic">N</Emphasis>-methylamines and their hydrohalides

Condensation of one molecule of α-methylaminoacetaldehyde dimethyl acetal with two molecules of resorcinol or methylresorcinol in hydrohalogen acid solutions led to substituted N-(2,2-diarylethyl)-N-methylamine hydrohalides. Reactions of the corresponding amines with acetic anhydride, mono-and diisocyanates, and formaldehyde were studied. Conditions for formation of calixarene from resorcinol and α-methylaminoacetaldehyde dimethyl acetal were invented. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 319–324, February, 2007.     

Polyfused nitrogen-containing heterocycles 18. 2′-Amino-5-methyl-1,2,3,4,4′,5′-hexahydrospiro[quinoxaline-2,4′-thiazol]-3-ones. Synthesis,structure, and recyclization

Bis-3-(α-bromoethyl)quinoxalin-2-ones with 3-oxapentane or 3,6-dioxaoctane spacer binding two heterocyclic fragments react with thiourea to give the corresponding bis-spirothiazoloquinoxalines, which upon treatment with acetic anhydride can be converted to podands with terminal thiazoloannulated quinoxaline fragments. X-Ray data for 2′-amino-4-ethyl-5-methyl-1,2,3,4,4′,5′-hexahydrospiro[quinoxaline-2,4′-thiazol]-3-one indicate for this compound a potentiality to form clathrate structures with various solvate molecules. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2386–2393, December, 2007.     

Imidazolylcardenolides

The new compounds strophanthidin-19-carbonylimidazole (1), erysimin-19-carbonylimidazole (2), cymarin-19-carbonylimidazole (3), and 17α-strophanthidin-19-carbonylimidazole (4) were synthesized by reacting cardenolide carboxylic acidsand N,N′-carbonyldiimidazole. It was shown for the first time that this reaction can be carried out with an angular carboxylic acid. The preparation and previously unknown properties of erysimin-19-carboxylic acid, cymarin-19-carboxylic acid, and 17α-strophanthidin-19-carboxylic acid were also described. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 373–374, July–August, 2008.     

Synthesis and structures of complexes ofN-2-nitroxyethylpicolinamide and 2-(2-pyridyl)-2-oxazoline with PdCl2

The reaction ofN,N′-bis(2-nitroxyethyl)pyridine-2,6-dicarboxamide with PdCl₂ afforded previously unknowncis-(N-2-nitroxyethylpicolinamide-N,N′)dichloropalladium(II) andcis-[2-(2-pyridyl)-2-oxazoline-N,N′]dichloropalladium(II), which were isolated as a cocrystallizate of the molecular compounds. Its structure was established by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1604–1606, August, 1999.     

Synthesis of poly(pyridazinoquinazolones)

A model reaction of 2-alkyl-3-aminoquinazolones with α-dicarbonyl compounds benzil and its 4, 4′-derivatives, acenaphthenequinone and isatin was studied for the first time. The reaction proceeded in pentafluorophenol and led to the formation of new heterocyclic systems. This approach was used in the synthesis of new thermostable polyheteroarylenes with fluorescent properties, viz., poly(pyridazinoquinazolones).     

Synthesis and complex-forming properties of thiazolyl-containing organophosphorus complexone

Alkaline hydrolysis of the previously prepared ethyl 2-methyl-2-[diethylamido-N-(4′-phenylthiazolyl-2-amido)phosphono]glycidate and 2-phenyl-2-[diethylamido-N-(4-phenylthiazolyl-2-amido)phosphono]glycidate accompanied by decarboxylation in situ of the obtained glycidic acids furnished 2-[diethylamido-(4′-phenylthiazolyl-2′-amido)phosphono]propionic and 2-phenyl-2-[diethylamido-(4′-phenylthiazolyl-2′-amido)phosphono]acetic aldehydes. The qualitative and quantitative evaluation of complex-forming ability of the compounds obtained with respect to transition metal ions was carried out. For identification of copper complex the evaluation of the stability constants of copper, cobalt, nickel, and zinc complexes was performed. Thermodynamic parameters of complex formation reactions were calculated. Correlation dependences between the physicochemical properties of metal ions and thermodynamic characteristics of complex formation with the organophosphorus ligands obtained were established.     

meta-Carborane-containing bismaleimides — New monomers for the synthesis of polyimides

The reaction of maleic anhydride with 1,7-bis(4,4-aminophenylamido)-m-carborane and 1,7-bis(4,4-aminophenylcarboxy)-m-carborane leads to the formation of the corresponding bis(maleamidocarboxylic acids) in quantitative yield. The subsequent dehydration of these compounds in a mixture of acetic anhydride and acetic acid in the presence of sodium acetate and triethylamine leads tom-carborane-containing bismaleimides, whose structure was indicated by IR spectroscopy. The chemical properties of these compounds were studied.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2446–2448, October, 1992.     

Phosphorylation of <Emphasis Type="Italic">N</Emphasis>-glycosides derived from <Emphasis Type="Italic">para</Emphasis>-substituted aromatic amines

New carbohydrate-containing aminophosphoryl compounds were synthesized on the basis of glycosylamines. The reaction pathway suggested for addition of hydrophosphoryl compounds to N-glycosides was confirmed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1986–1992, September, 2008.     

Spectral and fluorescent properties of cross-conjugated polyene ketones with terminalN-methylpyrrole residues

The spectral and fluorescent properties of a number of cross-conjugated ketones with one or two terminalN-methylpyrrole residues and those of polyene bis-ω, ω′-dimethylamino ketones with methyl substituents in the polyene chain and of some related compounds were studied. The photophysical properties of cross-conjugated ketones with terminalN-methylpyrrole residues are similar to those of the corresponding polyene bis-ω, ω′-dimethylamino ketones studied in detail previously. In both series of compounds, the absorption and fluorescence spectra undergo a bathochromic shift following an increase in the length of the polyene chains or introduction of α,α′-trimethylene or α,α′-dimethylene bridges into these chains; the same trend is observed on passing from less polar solvents to more polar solvents (positive solvatochromism). Thermochromism (long-wavelength shift of the absorption spectra upon cooling the solutions) is observed in both series of compounds. The introduction of methyl substituents into the polyene chains of bis-ω,ω′-dimethylamino ketones results in a decrease in the fluorescence quantum yield. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1293–1298, July, 1999.     

Trimethylsilyl derivatives of aliphatic nitro compounds in α,β-C,C-cross-coupling

A new α,β-C,C-cross-coupling reaction of derivatives of aliphatic nitro compounds, silyl nitronates andN,N-bis(silyloxy)enamines, leading to β-nitro oximes was found. The scope and limitations of this reaction were studied, and a mechanism was proposed.     

Reaction of trifluoromethanesulfonamide with alkenes and cycloocta-1,5-diene under oxidative conditions. Direct assembly of 9-heterobicyclo[4.2.1]nonanes

Reactions of trifluoromethanesulfonamide with α-methylstyrene, 2-methylpent-1-ene, and cycloocta-1,5-diene in the system t-BuOCl-NaI were studied. In the reaction with α-methylstyrene 1-iodo-2-phenylpropan-2-ol was the only isolated product. The reaction with 2-methylpent-1-ene gave a mixture of N,N′-(2-methylpentane-1,2-diyl)bis(trifluoromethanesulfonamide), trifluoro-N-(2-hydroxy-2-methylpentyl)-methanesulfonamide, and N,N′-[oxybis(2-methylpentan-2,1-diyl)]bis(trifluoromethanesulfonamide). Trifluoromethanesulfonamide reacted with cycloocta-1,5-diene to produce a mixture of 2,5-diiodo-9-(trifluoromethylsulfonyl)-9-azabicyclo[4.2.1]nonane and 2,5-diiodo-9-oxabicyclo[4.2.1]nonane; this reaction may be regarded as the first example of direct assembly of bicyclononane skeleton.     

Hydrophosphorylation of monosaccharides oximes and hydrazones

The hydrophosphorylation of monosaccharides oximes and hydrazones was studied; similarity and difference of this process compared to the reaction of secondary glycosylamines with the hydrophosphoryl compounds are shown. A number of the original α-aminophosphoryl compounds is obtained including those containing carbohydrate fragment in their compositions.     

2-[3-(Trifluoromethyl)phenyl]furo[3,2-b]pyrroles: synthesis and reactions

The synthesis and reactions of methyl 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole-5-carboxylate (1a) are described. Upon reaction with methyl iodide, benzyl chloride, or acetic anhydride, this compound gave N-substituted products 1b-d. By hydrolysis of compounds 1a-c, the corresponding acids 2a-c were formed, or by reaction with hydrazine-hydrate, the corresponding carbohydrazides 3a-c were formed. By heating 2-[3-(trifluoromethyl)phenly]-4H-furo[3,2-b]pyrrole-5-carboxylic acid (2a) in acetic anhydride, 4-acetyl-2-[3-(trifluoromethyl)phenyl]furo[3,2-b]pyrrole (4) was formed. By hydrolysis of 4, 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole (5a) was formed, and reactions with methyl iodide or benzyl chloride gave N-substituted products 5b-c. The reaction of 4 with dimethyl butynedioate gave substituted benzo[b]furan 6. Compound 3a reacted with triethyl orthoesters giving 7a-c, which afforded with phosphorus (V) sulphide the corresponding thiones 8a-c. The thiones 8a-c reacted with hydrazine hydrate to form hydrazine derivatives 9a-c. The reaction of triethyl orthoformiate with compounds 9a-c led to furo[2′,3′: 4,5]pyrrolo[1,2-d][1,2,4]triazolo[3,4-f][1,2,4]triazines 10a-c. Hydrazones 11a-c were formed from 3a-c and 5-[3-(trifluoromethyl)phenyl]furan-2-carboxaldehyde. The effect of microwave irradiation on some condensation reactions was compared with “classical” conditions. The results showed that microwave irradiation shortens the reaction time while affording comparable yields.     

Epimerization,transacylation and bromination of dihydroquercetin acetates; synthesis of 8-bromodihydroquercetin

Dihydroquercetin (dhq) and its 3-acetate react with acetic anhydride in the absence of a base catalyst to yield mixtures of partially acetylated products. Three new esters were characterized by NMR spectroscopy as dhq 3,7,3′-triacetate, 3,7,4′-triacetate and 5,7,3′,4′-tetraacetate. At its melting point neat dhq 3,7,3′,4′-tetraacetate is partially converted to dhq 3,3′,4′-triacetate and dhq pentaacetate by intermolecular acetyl transfer. Dhq 7,3′,4′-triacetate yields exclusively dhq 3′,4′-di- and 3,7,3′,4′-tetraacetate under these conditions. The acetylation/deacetylation reactions are accompanied by partial epimerization: 3 new acetates with 2,3-cis stereochemistry (dhq 3-, 3,7,3′,4′-tetra- and penta-) were identified. Dhq and its 3,7,3′,4′-tetraacetate undergo regiospecific dibromination at C-6 and C-8 with excess N-bromosuccinimide in polar solvents, and 6,8-dibromo-dhq can be regioselectively debrominated to 8-bromo-dhq with sodium sulfite.     

The products of phosphorylation of <Emphasis Type="Italic">N,N</Emphasis>-dialkylureas and dialkylcyanamides with phosphorus pentachloride. NMR spectroscopy study

The study by ¹H and ³¹P NMR spectroscopy has shown that phosphorylation of N,N-dimethylurea and diethylcyanamide with phosphorus pentachloride results in the formation of N′-(N,N-dialkylchloroformamidino) trichlorophosphonium hexachlorophosphorates where the positive charge of the organyltrichlorophosphonium cation is delocalized over the system of the multiple bonds with participation of the lone electron pair of the nitrogen atom. Bis-N′-(N,N-dialkylchloroformamidino)dichlorophosphonium hexachlorophosphorates, dichlorides of N,N-dialkylchloroformamidinophosphonic and thiophosphonic acids are synthesized where the conjugation of the phosphorus-containing substituent with the chloroformamidinium part of the molecules is retained. Organyltetrachlorophosphoranes based on N,N-dimethylurea and diethylcyanamide exist in polar and nonpolar solvents as orhanyltrichlorophosphonium chlorides.     

Reaction of <Emphasis Type="Italic">N,N</Emphasis>′-bis(trimethylsilyl)dicyandiamide with bis(η<Superscript>5</Superscript>-cyclopentadienylvanadium) dichloride

1,3,5-Tris[bis(η⁵-cyclopentadienyl)chlorovanadium]melamin is prepared in high yield by the reaction of N,N′-bis(trimethylsilyl)dicyandiamide with bis(η⁵-cyclopentadienylvanadium) dichloride in tetrahydrofuran. As side products, trimethylchlorosilane and cyclopentadiene formed. Reaction of N,N′-bis(trimethylsilyl) dicyandiamide with benzoyl chloride results in the formation of tris(benzoyl)melamin.