Synthesis and structure of the complex of 2-(2-pyridyl)-2-oxazoline with PdCl2

The reaction ofN-2-nitroxyethylpicolinamide with PdCl₂ afforded the new complexcis-[2-(2-pyridyl)-2-oxazoline-N,N′]dichloropalladium(u). The structure of this complex was established by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 561–563, March, 2000.     

Alkylation of salts ofN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxides with alkyl halides and dimethyl sulfate

Salts ofN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxides, RCH(OH)CH₂N(O)=NO⁻ M⁺ (R=Me, Prⁱ, or Bu^t; and M=Li, Na, K, Ag, NH₄, or Me₄N), were prepared. Their alkylation with alkyl halides R′X (X=Cl, Br, or I) and dimethyl sulfate was studied. Generally, alkylation afforded mixtures ofN-(β-hydroxyalkyl)-N′-alkoxydiazeneN-oxides RCH(OH)CH₂N(O)=NOR′ andO-alkyl-N-(β-hydroxyalkyl)-N-nitrosohydroxylamines RCH(OH)CH₂N(NO)OR′. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1996–2001, October, 1998.     

Intramolecular cyclization ofN-acetyl-6-(cyclopent-1-enyl)-2-methylaniline

N-Acetyl-6-(cyclopent-1-enyl)-2-methylaniline underwent intramolecular cyclization in the presence of HCl in CH₂Cl₂ at 20°C to form 2,8-dimethylspiro[cyclopentane-1,4′-4′H-3,1-benzooxazine] in quantitative yield. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 398–400, February, 1999.     

Synthesis of 2-(2-hydroxyaroylmethylene)hexahydropyrimidines from 2-trichloromethylchromones and trimethylenediamine

The reactions of 2-trichloromethylchromones with trimethylenediamine in ethanol at room temperature afford 2-(2-hydroxyaroylmethylene)hexahydropyrimidines. Under analogous conditions, 2-methylchromone gives a mixture ofN,N′-trimethylenebis[3-amino-1-(2′-hydroxyphenyl)-2-buten-1-one] andN,N′-trimethylenebis(imine) of 2-hydroxyacetophenone. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2140–2143, November, 1999.     

Thiocarbamoylation of amine-containing compounds

Thiocarbamoylation of 5-aminosalicylic acid with tetramethylthiuram disulfide afforded 5-(N′,N′-dimethylthioureido)salicyclic acid. Treatment of the latter with mineral acids or Ac₂O gave 5-isothiocyanatosalicylic acid whose reaction with ethanolamine yielded 5-[N′-(2-hydroxyethyl)thioureido]salicylic acid. The latter underwent cyclization under the action of TsOH to form 5-(2-thiazolin-2-ylamino)salicylic acid. For Part 2, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2315–2318, December, 1999.     

1-( p -Fluorophenyl)-2-(2′-pyridyl)ethanol and 1-( p -fluorophenyl)-2-(2′-pyridyl)ethene obtained from the condensation reaction of 2-picoline and p -fluorophenylaldehyde under catalyst-and solvent-free conditions

The novel intermediate 1-(p-fluorophenyl)-2-(2′-pyridyl)ethanol or 2-[2′-(1-hydroxy-1-(p-fluorophenyl)ethyl]pyridine and the corresponding novel dehydration compound 1-(p-fluorophenyl)-2-(2′-pyridyl)ethene or 2-[p-fluorophenylvinyl]pyridine were obtained from the condensation reaction of p-fluorophenylaldehyde and 2-picoline under catalyst-and solvent-free conditions. The intermediate 1-(p-fluorophenyl)-2-(2′-pyridyl)ethanol was obtained at 42 h reaction time and temperature of 120°C, respectively. ¹H-NMR, IR spectroscopic data of the 1-(p-fluorophenyl)-2-(2-pyridyl)ethanol clearly showed the presence of the-CH₂-CHOH-group. The compound was obtained as a white powder with m.p. 121–122°C and a yield of 8%. For 1-(p-fluorophenyl)-2-(2-pyridyl)ethene, the reaction conditions were similar, but the reaction temperature was increased to yield the double bond in the 1-(p-fluorophenyl)-2-(2′-pyridyl)ethene. At the reaction temperature of 140°C, the compound was a slightly brown powder with a m.p. of 78°C and yield of 18%. ¹H-NMR, IR spectroscopic data for the 1-(p-fluorophenyl)-2-(2′-pyridyl)ethene showed the presence of a double bond in trans configuration (-CH=CH-), characteristic of a styrylpyridine.     

Synthesis and the crystal structures of N-(2-nitroxyethyl)isonicotinamide and its complexes with PdCl2 and PtCl2 as potential antitumor medicines

Previously unknown N-(2-nitroxyethyl)isonicotinamide was synthesized by the reaction of isonicotinoyl chloride with 2-nitroxyethylamine and was used as a ligand in the reactions with PdCl₂ and PtCl₂ to prepare new complexes, viz., trans-bis[(2-nitroxyethyl)isonicotinamide-N]dichloropalladium(ii) and cis-bis[(2-nitroxyethyl)isonicotinamide-N]dichloroplatinum(ii), respectively. The structures of the ligand and the resulting complexes were established by X-ray diffraction analysis.     

Solvation Structure and Complexation of the Manganese(II) Ion in N,N-Dimethylpropionamide and N,N,N′,N′-Tetramethylurea Studied by Means of Titration Calorimetry and Raman Spectroscopy

Aprotic N,N-dimethylpropionamide (DMPA) and N,N,N′,N′-tetramethylurea (TMU) are both strong donor solvents and coordinate to metal ions through the carbonyl oxygen atom. These solvents show a different conformational aspect in the bulk phase, i.e., DMPA exists as either a planar cis or a nonplanar staggered conformer, while TMU exists in a single planar cis conformer. It has been established that the manganese(II) ion is solvated by five molecules in both solvents. Interestingly, although the planar cis conformer of DMPA is more favorable than the nonplanar staggered one in the bulk phase, the reverse is the case in the coordination sphere of the metal ion, i.e., a conformational change occurs upon solvation. To reveal the thermodynamic aspect of this conformational change, the complexation of Mn(II) with bromide ions in DMPA and TMU has been studied by titration calorimetry at 298 K. It was found that the Mn(II) ion forms mono-, di- and tri-bromo complexes in both solvents, and their formation constants, enthalpies and entropies were obtained. The Δ H∘₁ value for MnBr⁺ strongly depends on the solvent, i.e., it is positive (19.4 kJ-mol⁻¹) in DMPA and negative (−8.7 kJ-mol⁻¹) in TMU, whereas the Δ H^∘₂ and Δ H∘₃ values for the stepwise formation of MnBr₂ and MnBr₃⁻ are both small and negative. The enthalpy of transfer Δ_tH^∘ from DMPA to TMU, which is evaluated on the basis of the extrathermodynamic TATB assumption, is 25.5 kJ-mol⁻¹ for Mn²⁺ and −3.6 kJ-mol⁻¹ for MnBr⁺. These values indicate that the difference between the formation enthalpy of MnBr⁺ in the two solvents, Δ H^∘₁ (DMPA) – Δ H∘₁ (TMU), is mainly ascribed to the value of Δ_tH^∘(Mn²⁺). It is found that the metal ion is also five-coordinated in the monobromo complex, MnBr(DMPA)₄⁺ . The enthalpy for the conformational change of DMPA from its planar cis to the nonplanar staggered form is evaluated to be −11 and −5.5 kJ-mol⁻¹ for Mn(DMPA)₅^{2 +} and MnBr(DMPA)₄⁺, respectively. Note that these values are significantly smaller than the corresponding value (5.0 kJ-mol⁻¹) in the bulk phase. We thus conclude that, although steric hindrance among solvent molecules is reduced by replacing one DMPA of Mn(DMPA)₅^{2 +} with the relatively small bromide ion, DMPA molecules are still sterically hindered in the MnBr(DMPA)₄⁺ complex.     

Reactions of 2-(4,5-dihydro-3-furyl)-1,3-diphenyl-1,3-diaza-2λ<Superscript>3</Superscript>-phospholidine and 4,5-dihydro-3-furylphosphonous diamides with nitrile imines

Reactions of 2-(4,5-dihydro-3-furyl)-1,3-diphenyl-1,3-diaza-2λ³-phospholidine (1) with nitrile imines are multistep processes involving cleavage of one P-N bond of the diazaphospholidine ring to form substituted 5-(2-chloroethyl)-4-(N,N′-diphenylethylenediamino)-1,4-dihydro-1,2,4λ⁵-diazaphosphorines 4 as final products. Analogs of phospholidine 1, namely, 4,5-dihydro-3-furylphosphonous dipiperidide and dimorpholide, react with C,N-diphenylnitrile imine with retention of both P-N bonds to give 5-(2-hydroxyethyl)-1,2,4-diazaphosphorinium chlorides. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1590–1593, July, 2005.     

Theoretical study on the hydrolysis mechanism of N,N -dimethyl- N ′-(2′,3′-dideoxy-3′-thiacytidine)formamidine

The hydrolysis mechanisms of N,N-dimethyl-N′-(2′,3′-dideoxy-3′-thiacytidine)formamidine (FA-3TC) in the gas phase and in aqueous solution were studied by use of the density functional theory B3LYP/6-31+G(d, p) method. Two possible reaction pathways in the title reaction were considered. In one pathway water attacks the C=N double bond first (path A) while in the other water attacks the C-N single bond first (path B). The calculated results indicate that the first step in both pathways is the rate-limiting process and path A is more favorable than path B in the gas phase. The effect of solvent water on the title reaction was assessed at the B3LYP/6-31+G(d, p) level of theory based on the polarizable continuum model (CPCM). In water the first mechanism (path A) is also favored. Supported by the National Natural Science Foundation of China (Grant Nos. 20473055 and 20773089) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (Grant No. 20071108-18-15)     

Vinamidinium salts of N-substituted aminoacetic acids

Formylation of N-phthaloylglycine with the POCl3-DMF system afforded N,N,N′, N′-tetramethyl-2-(N-phthaloyl)vinamidinium perchlorate (2). X-ray diffraction study showed that molecule 2 is planar and contains two equivalent nitrogen atoms in the three-carbon vinamidinium fragment. Salt 2 undergoes transamination with primary aromatic amines to give the corresponding bis-azomethines. The reactions with hydrazines produce substituted 4-aminopyrazoles. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 832–835, May, 2006.     

OH−-induced β-elimination reactions with 1-(2-Xethyl)-4-nitrobenzene substrates in solvent mixture H2O/CH3CN and H2O/DMSO: Reactivity and mechanism

The behaviour of 1-(2-bromoethyl) 4-nitrobenzene (1), N,N,N-triethyl-2-(4-nitrophenyl)ethanaminium bromide (2) and N,N-diethyl-N-[2-(4-nitrophenyl)ethyl]octan-1-aminium bromide (3) in the OH⁻-induced elimination reactions with formation of 1-nitro-4-vinylbenzene in mixtures of DMSO/H₂O or CH₃CN/H₂O has been investigated. With all three substrates an increase in dipolar aprotic solvent content implies a limited increase of the second-order rate constant k _OH up to ≅605, and then an exponential increase is observed. The variation of activation parameters ΔH ^# and dGS ^#, measured in DMSO/H₂O mixtures, is parallel for 1 and 2. This similar behaviour of 1 and 2 with respect to variation in solvent composition is evidence that it is not possible to use this technique of solvent effect for the mechanistic diagnosis of elimination reactions.     

Reaction of 2-(4,5-dihydrofur-3-yl)-1,3-diphenyl-1,3-diaza-2-2λ3-phospholidine withC,N-diphenylnitriliminewithC,N-diphenylnitrilimine

The reaction of 2-(4,5-dihydrofur-3-yl)-1,3-diphenyl-1,3-diaza-2λ³-phospholidine withC,N-diphenylnitrilimine is a multistage process, in the course of which the 1,2,4-diazaphosphorine ring is formed and both rings of the initial organophosphorus compound are cleaved. 5-(2-Chloroethyl)-4-(N,N′-diphenylethylenediamino)-1,3-diphenyl-1,4-dihydro-1, 2,4λ⁵-diazaphosphorine was obtained as the final product. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 125–128, January, 2000.     

Preparation of (2′-5′)-oligonucleotides based on 6-<Emphasis Type="Italic">N</Emphasis>-benzylaminopurineriboside using the <Emphasis Type="Italic">Spicaria violacea</Emphasis> fungal enzyme complex

A method for chemico-enzymatic synthesis of (2′-5′)-oligonucleotides with 6-N-benzylaminopurineriboside as the nucleoside units was proposed. The method consisted of enzymatic hydrolysis of the oligonucleotides with mixed (2′-5′)-(3′-5′)-phosphodiesterbonds that were prepared by polymerization of 6-N-benzyladenosine-2′(3′)-monophosphate by using (3′-5′)-specific nuclease and phosphatase contained in the filtrate of culture medium of the mycelial fungus Spicaria violacea. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 64–68, January–February, 2009.     

The reaction of salts ofN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxides with dihalomethanes

Methylene-bis[N′-oxydiazene-N-(β-hydroxyalkyl)N-oxides] were synthesized by the reaction of salts ofN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxides with diahalomethanes. The effect of the nature of the starting reagents and the reaction condtions on the yields of the target compounds was studied. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2266–2269, November, 1998.     

Reactions of functionalized alkyl halides withN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxide salts

Some characteristic features of reactions ofN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxide salts with various α- and β-functionalized alkyl halides were established. Some α-and β-functionalizedN-(β-hydroxyalkyl)-N′-alkoxydiazeneN-oxides and e ethylenebis[N-(β-hydroxyalkyl)-N′-oxydiazeneN-oxides] were synthesized for the first time. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 123–129, January, 1999.     

Imino <Emphasis Type="Italic">Diels-Alder</Emphasis> Reactions: Efficient Synthesis of 2-Aryl-4-(2′-oxopyrrolidinyl-1′)-1,2,3,4-tetrahydroquinolines catalyzed by Antimony(III) Sulfate

Summary. Antimony(III) sulfate is found to catalyze the imino Diels-Alder reaction of Schiff’s bases with N-vinylpyrrolidin-2-one to afford 2-aryl-4-(2′-oxopyrrolidinyl-1′)-1,2,3,4-tetrahydroquinolines. One-pot synthesis of 1,2,3,4-tetrahydroquinolines from 3-nitro benzaldehyde and aromatic amines with N-vinylpyrrolidin-2-one catalyzed by antimony(III) sulfate is also reported. This catalyst is inexpensive, easily available, and it was also found that catalyst could be recovered quantitatively and reused without much loss of catalytic activity.     

Simultaneous separation and determination of Cu(II), Fe(III), and Pb(II) by reversed-phase ion-pair chromatography withN,N,N′, N′-ethylene-diaminetetrakis(methylenephosphonic Acid)

Summary A reversed-phase ion-pair chromatographic (RPIPC) method withN,N,N′, N′-ethylenediaminetetrakis(methylenephosphonic acid) (EDTMP) as coordinating agent has been developed for simultaneous separation and detection of Cu(II), Fe(III), and Pb(II) ions. Response is linearly dependent on amount of sample over the range 9.52–50.8 μg mL⁻¹ for Cu(II), 8.31–41.8 μg mL⁻¹ for Fe(III), and 37.3–51.8 μg mL⁻¹ for Pb(II). The method has been applied successfully to an artificial mixed-ore sample.     

Two-fragment α-adrenolytics

Dialkyl β-(2-aroxyethylamino)ethylphosphonates,N-[β-(2-methoxyphenoxy)ethyl]-N′-[β-(diethoxyphosphoryl)ethyl]-α,ω-diaminoalkanes, and diethyl β-(N-arylpiperazino)ethyl-phosphonates were synthesized by the reactions of dialkyl vinylphosphonates with β-aroxyethylamines,N-[β-(2-methoxyphenoxy)ethyl]-α,ω-diaminoalkanes, andN-aryl-piperazines, respectively. The compounds synthesized exhibit hypotensive and α-adrenolytic activities. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 987–991, May 1999.