Amination of isomeric bromo-1-methylnitropyrazoles

A method was developed for the synthesis of 5-bromo-1-methyl-4-nitropyrazole from 1-methylpyrazole. In the reaction with 25% aqueous ammonia at 180–190 °C, 5-bromo-1-methyl-4-nitropyrazole is readily converted to 5-amino-1-methyl-4-nitropyrazole; the production of 4-amino-1-methyl-5-nitropyrazole from 4-bromo-1-methyl-5-nitropyrazole requires the presence of a copper catalyst; under the same conditions in the amination of 4-bromo-1-methyl-3-nitropyrazole, 4-amino-1-methyl-3-nitro- and 1-methyl-3-nitropyrazoles are formed in a 23 ratio.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1672–1675, December, 1983.     

Investigation of the structure and thermolysis of quaternary salts of 2-alkyl- and 2-arylamino derivatives of thiazolines

2-Arylamino derivatives of 5-methylthiazoline react with alkyl iodides to give quaternary salts with primarily an exocyclic orientation of the C=N bond, while the C=N bond is localized in the: ring in the corresponding salts of 2-alkylamino derivatives of thiazoline. The decomposition of these salts leads to the corresponding 2-arylaminothiazolidines and 2-alkylaminothiazolines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 917–920, July, 1981.     

Characteristic features of the reaction of 3(5)amino-5(3)-methylpyrazole with 1-nitroanthraquinone-2-carboxylic acid

In the reaction of 3(5)-amino-5(3)-methylpyrazole with 1-nitroanthraquinone-2-carboxylic acid in sulfolane at 150°C, 2-methyl-pyrazolo[5,1-b]naphtho[2,3-h]quinazoline-5,10,13-trione is formed with an admixture of 1-aminoanthraquinone-2-carboxylic acid and 1-aminoanthraquinone. Under similar conditions, from 4-amino-1,5-dimethylpyrazole, only 1-(1,5-dimethyl-4-pyrazolylamino)anthraquinone-1-carboxylic acid is formed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1191–1192, September, 1992.     

Catalytic synthesis of diazines from 1,3-diaminopropane and 3-amino-1-propanol

The transformations of 1,3-diaminopropane and 3-amino-1-propanol under pulse conditions over tungsten trioxide in an inert atmosphere at 300–500 °C were investigated. The transformation of 1,3-diaminopropane leads to the formation of saturated pyrimidine bases; the maximum selectivity of the formation of hexahydropyrimidine bases at 300 °C is 60%, while the selectivity of the formation of tetrahydropyrimidine bases is 20% (400 °C). In the case of 3-amino-1-propanol the overall yield of heterocyclic bases was less than 5%, and piperazine and pyrazine derivatives were observed as the cyclic products; the formation of pyrimidine bases was not observed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 967–973, July, 1982.     

Researches on 2, 1, 3-thia- and selenadiazole

4-Hydroxy-, 4-hydroxy-5-methyl-, 4-hydroxy-7-methylbenzo-2,1,3-thiadiazoles are polymorphous.4-Hydroxybenzo-2,1,3-thiadiazole (I), 4-hydroxy-5-methyl- and 4-hydroxy-7-methylbenzo-2, 1, 3-thiadiazoles (II and III) melt at 114–115°, 110–112°, 100–102° C, respectively, after recrystallization from water [2–4], but after recrystallization from petrol ether [5] they melt at 128–129°, 124–125°, and 119–120° C [5]. In this connection we recrystallized these phenols repeatedly from petrol ether after recrystallizing them from water, and their melting points rose as expected [5]. On the other hand, the compounds with melting points 128–129°, 124–125°, 119–120° C (ex petrol ether), after repeated crystallization from water melted at 114–115°, 110–112°, 100–102° C, respectively.For Part XXXVIII see [1].     

Reaction of anthranilic acid and methoxy- and nitro-substituted anthranilic acid with p-toluenesulfonyl chloride in pyridine

The reaction of anthranilic acid and methoxy- and nitro-substituted anthranilic acid with p-toluenesulfonyl chloride in pyridine was investigated. Anthranilic acid and its methoxy-substituted derivatives react to give the corresponding 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-ones and N,N'-ditosyldianthranilides. At 20°C, 4-nitroanthranilic acid gives primarily 2-(2-amino-4-nitrophenyl)-7-nitro-4H-3,1-benzoxazin-4-one, while its tosyl derivative is obtained at 114°. The products of the reaction of 5-nitroanthranilic acid with p-toluenesulfonyl chloride are 2-nitro-11H-pyrido[2,1-b]quinazolin-11-one and 2-(2-amino-5-nitrophenyl)-6-nitro-4H-3, 1-benzoxazin-4-one. The yield of benzoxazinone generally increases as the temperature is raised.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1341–1344, October, 1972     

Synthesis of vinylsulfonyl(halo)pyridines and their reactions with binucleophilic reagents

Oxidation of vinylthio(halo)pyridines with 30–33% hydrogen peroxide solution in acetic anhydride at 20–25°C furnished vinylsulfonyl(halo)pyridines. Nucleophilic addition reactions of 2-amino-1-ethanethio hydrochloride and thiosemicarbazide to the multiple bonds of vinylsulfonyl(halo)pyridines were performed.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 11, 2004, pp. 1705–1708.Original Russian Text Copyright © 2004 by Amosova, Gavrilova.     

Synthesis of derivatives of 4-imino-2-amino-2-imidazoline. New example of a multicomponent condensation involving isonitriles

Isonitriles have been found to react with ketones and ammonium and methylammonium thiocyanates in methanol or ethyleneglycol at 20 °C to form derivatives of 4-imino-2-amino-2-imidazoline and 2,4-diaminoimidazolium salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 53–61, January, 1986.     

Synthesis of nitrogen containing heterocycles over copper chromite

The reactions of 1,2-diaminopropane, 1-amino-2-propanol, 1-amino-2-ethanol and N-(-aminoethyl)-1,2-diaminoethane in the gas phase over copper chromite have been investigated with the objective of synthesising nitrogen containing heterocycles. At 240–360°C 1,2-diaminopropane gave principally methyl- and 2,5-dimethylpyrazine, whereas the basic reaction for 1-amino-2-propanol was dehydration to give 1-aminoethyl-2-methylaziridine (with a selectivity of up to 78%). The main cyclic product from the dehydration of 1-amino-2-ethanol was pyrazine, while piperazine was farmed together with pyrazine from N-(-amonoethyl)-1-2-diaminoethane.Latvian Institute of Organic Synthesis, Riga, LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 950–957, July, 1994.     

Nitrile splitting in 2-amino-1-(arylmethyleneamino)-5-aryl-3,4-dicyanopyrroles

Nitrile splitting of the N–N bond with formation of 2-amino-5-aryl-3,4-dicyanopyrroles and the corresponding benzonitrile occurs when 2-amino-5-aryl-1-(arylmethyleneamino)3,4-dicyanopyrroles are boiled in DMSO in the presence of alkali.N. I. Ul'yanov Chuvash State University, Cheboksary 428015, Russia; e-mail:anatoly5@chuvs.ru. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1627–1629, December, 1999.     

Selective acid hydrolysis of 2-substituted-5-dimethylaminomethyleneaminopyrimidines to 5-amino- and 5-hydroxypyrimidines

Conditions are described for the selective acid hydrolysis of 2-substituted-5-dimethylaminomethyleneaminopyrimidines in 0.2–2 M sulfuric acid, to give high yields of the corresponding 5-amino- and difficultly accessible 5-hydroxypyrimidines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 801–803, June, 1990.     

Organosoluble and light-colored fluorinated polyimides based on 9,9-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]fluorene and aromatic dianhydrides

A novel fluorinated diamine monomer, 9,9-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]fluorene (II) was prepared via the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride with 9,9-bis(4-hydroxyphenyl)fluorene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides V were synthesized from diamine II and various aromatic dianhydrides III _a-f via thermal imidization. These polymers had inherent viscosities ranging from 0.84 to 1.03 dL/g and were soluble in a variety of organic solvents such as NMP, DMAc, DMF, and DMSO, and some could even be dissolved in less polar solvents such as m-cresol, pyridine, and dioxane. Polyimide films V _a-f had tensile strengths of 85–105 MPa, elongations to break of 7–9%, and initial moduli of 2.13–2.42 GPa. The glass transition temperature of these polymers were in the range of 277–331 °C, their 10% weight loss temperatures were in the range of 539–594 °C in nitrogen and above 544 °C in air, and their char yields at 800 °C in nitrogen ranged between 55–65 wt%. Compared with nonfluorinated polyimides VI, V showed better solubility and lower color intensity. Low dielectric constants (2.68–2.85 at 1 MHz) and low moisture absorptions (0.12–0.24 wt%) were also observed. In particular, V _c-f afforded lightly-colored films, which had cutoff wavelengths lower than 385 nm and b* values ranging from 6 to 22.     

Spectrophotometric determination of vanadium(V) with p-Sulphobenzeneazo-4-(2-amino-3-hydroxypyridine)

Summary p-Sulphobenzeneazo-4-(2-amino-3-hydroxypyridine) reacts with vanadium to form an orange-red coloured complex having maximum absorbance at 530 nm. The reaction is slow at room temperature, it is complete at 40–45° C in 5 min. The effects of temperature, time, pH, reagent concentration, and other variables have been studied. The system obeys Beer's law over the concentration range of 1–12g vanadium(V) ml^–1. The molar absorptivity is 5.453 x 10³l·mole^–1·cm^–1. The metal:ligand ratio of 12 was confirmed by Job's continuous variation and mole ratio methods.

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Spektrophotometrische Bestimmung von Vanadin(V) mit p-Sulfobenzolazo-4-(2-amino-3-hydroxypyridin)

Zusammenfassung p-Sulfobenzolazo-4-(2-amino-3-hydroxypyridin) bildet mit Vanadin(V) einen orange-roten Komplex, dessen Absorptionsmaximum bei 530 nm liegt. Bei Zimmertemperatur verläuft die Reaktion langsam, bei 40–45° ist sie in 5 min vollständig. Der Einfluß von Temperatur, Zeit, pH, Reagenskonzentration und anderer variabler Faktoren wurde untersucht. Im Konzentrationsbereich 1–12g Vanadin/ml entspricht die Reaktion dem Beer-schen Gesetz. Die molare Absorptivität ist 5,453 x 10³l·mol^–1·cm^–1. Das Verhältnis Metall:Ligand wurde nach Job bestimmt und beträgt 12.

     

New Benzo-15-Crown-5 Ethers Featuring Salicylic Schiff Base Substitutions – Synthesis, Complexes and Structural Study

Condensation reactions between 4'-formyl-5'-hydroxybenzo-15-crown-5and 2-aminopyridine, 2-amino-6-methylpyridine, 2-amino-4-methylpyridine or2-(aminomethyl)furan yielded the new laterally functionalized crown ethers1–4. The crown compounds 1–3 form crystalline 1:1 (Na⁺:ligand) complexes 1a–3a with sodium perchlorate. Ligands and complexes have been characterized by elemental analyses, IR, UV-Vis, ¹H-, ¹³C-NMR and mass spectra. The tautomeric equilibria (phenol-imine, O...H–N and keto-amine, O...H–N forms) have been systematically studied by using UV-Vis absorption spectra. The spectra of the ligands 1–4 and complexes 1a–3a were recorded in polar, non-polar, acidic, and basic media. In solutions of polar solvents, tautomeric interconversion of the Schiff base into the keto-amine form has been observed. A crystal structure [monoclinic, space group P2₁/c,a = 14.292(2), b = 9.449(6), c = 16.059(2) Å, = 114.20(1)°,V = 1978.4(13) ų, Z = 4 and D_x = 1.314 g cm^-3] shows that compound 4 is in the form of phenol-imine in solid state. There is a strong intramolecular [O–H...N 1.78(6), O...N 2.581(7), O–H 0.89(6) Å and N...H–O 148.4(5)°] hydrogen bond between the phenolic oxygen and imine nitrogen atoms. The C=N imine bond reveals a trans planar (1E) configuration. The molecules stack in columns parallel to the a/c plane of the unit cell.     

New method for the synthesis of 2-(9-adeninyl)alkanediols

Condensation of 4-amino-5-nitro-6-chloropyrimidine with 2-amino-1,3-dihydroxypropane and 2-amino-1,4-dihydroxybutane gave 4-amino-5-nltro-6-dihydroxyalkylpyrimidines, which are cyclized to 2-(9-adeninyl)alkanediols after reduction of the nitro group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 129–130, January, 1973.     

Synthesis of derivatives of 2-amino-1,3,4-oxadiazole-5-hydroxamic acid

A series of derivatives of 2-amino-1,3,4-oxadiazole-5-hydroxamic acid has been prepared by the reaction of 2-amino-5-chloroximinomethyl-1,3,4-oxadiazole with nucleophiles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, 529–531, April, 1993.     

Dipole moments,kerr constants,and conformations of some substituted methyl cyclopropyl ketones

Conclusions The acetyl group in a substituted cyclopropane ring has an s-cis conformation that is distorted by either 15–20° (cis-2-halo-cis-3-methyl derivatives) or by 55–70° (cis-2-halo-1-methyl derivatives).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1174–1177, May, 1977.     

Synthesis of derivatives of 5-amino-7-oxo(6h)-1,3-dithiolo[4,5-d]pyrimidine on the basis of 2-amino-(1h,5h)pyrimidine-4,6-dione

The betaine of 2-amino-5-phenyliodonio(1H,5H)pyrimidine-4,6-dione, upon interaction with sodium diethyldithiocarbamate, forms the previously unknown 2-amino-5-diethylaminothiocarbonylthio (1H,5H)pyrimidine-4,6-dione, the cyclization of which in concentrated sulfuric acid leads to salts of 2-diethylimmonio-5-amino(6H)-1,3-dithiolo[4,5-d]pyrimidin-7-one — a new heterocyclic system. The salts serve as the starting material for obtaining 5-amino-7-oxo(6H)-1,3-dithiolo[4,5-d]pyrimidine-2-selenone and -2-thione.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1117–1121, August, 1992.     

Kinetik der Diazotierung des Anilins in methanolischer Bromwasserstoff- und Chlorwasserstofflösung, 2. Mitt.

The kinetics of the diazotization of aniline in 0.003n to 0.4n methanolic HBr-and HCl-solution, resp., were determined (HBr at 25 and 15°C, HCl at 25, 15, –10, –20, and –30°C).It was found that the nitrosation reaction is a preceeding advance-back-reaction.The velocity coefficients of the nitrosation from bromide (at 15 and 25°C) and from chloride (at 25, 15, –10, –20, and –30°C) were determined. The decomposition of I (splitting off a proton) is the rate determining reaction. The free enthalpies of activation for the nitrosation reaction above bromide and chloride at the said temperatures are calculated (table 3).     

Chemical behavior of 5-alkoxy-2-alkylthiophenes under the conditions of the vilsmeier reaction

Dealkylation of the methoxy group and formation of N-substituted 5-alkyl-3-aminomethylene-4-thiolen-2-ones occur during the action of substituted formamides and phosphorus oxychloride on 5-methoxy-2-alkylthiophenes on heating at 50–70 deg C. At 20 deg the major reaction products are 5-alkyl-2-methoxy-3-formylthiophenes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 171–177, February, 1971.