[2 + 2]-Cycloadditions to Strained Bridgehead Olefins. II. Diphenylketene

The strained bridgehead olefins bicyclo [3.3.1]non-1-ene ( 1 ), bicyclo [4.2.1 ]non-1(8)-ene ( 2 ), and bicyclo [4.2.1]non-1-ene (3), and the comparable monocyclic (E)-1-methylcyclooctene ( 4 ) react with diphenylketene ( 6 ) to give a single cycloadduct 7 , 8 , 9 and 10 , respectively, in which the diphenyl-substituted C-atom is bound to the bridgehead. The structure of the cyclobutanone 8 has been determined by X-ray analysis of a twin crystal obtained by crystallization with spontaneous enrichment of enantiomers.     

Condensed isoquinoline. 5. Reaction of the 6-methyl-5-oxoisoquino[2,3-a] Quinazolinium cation with certain nucleophiles

It has been shown that nucleophilic reagents react with the 6-methyl-5-oxoisoquino[2,3-a]quinazolinium cation at the C₍₂₎ atom. The structure of the reaction product is determined by the type of reagent. On reaction with sodium borohydride and secondary amines, 12H- and 12-dialkylamino-12H-6-methyl-5-oxo-5, 6-dihydroisoquino[2,3-a]quinazolines are formed. In the case of primary amines the reaction is accompanied by fission of the C₍₁₂₎-N_(t3) bond with the formation of 2-[o-(N-alkylformimidoyl)-benzyl]-3-methyl-4-oxoquinazolines.See [1) for the preceding communication.T. G. Shevchenko Kiev University, Kiev 252017. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 522–526, April, 1995. Original article submitted March 24, 1995.     

Research on naphthyridines. 10. Synthesis and ionization constants of 10-alkylaminobenzo[b]-1,8-naphthyridines

10-Alkylaminobenzo[b]-1,8-naphthyridines were synthesized by cyclization of 2-arylaminonicotinic acid alkylamides by means of phosphorus oxychloride. The pK_al values of the 10-alkylaminobenzo[b]-1,8-naphthyridines, which range from 8.74 to 8.50, were determined by potentiometric titration in anhydrous ethanol.See [1] for communication 9.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 799–801, June, 1979.     

Über Chalkogenolate. 104. Untersuchungen über Halbester der Monothiokohlensäure. 3. Kristallstruktur von Kaliummethyloxoxanthat

On Chalcogenolates. 104. Studies on Hemiesters of Monothiocarbonic Acid. 3. Crystal Structure of Potassium Methyl Oxoxanthate K[SOC? OCH₃] crystallizes with Z = 4 in the monoclinic space group P2₁/n with cell dimensions a = 6.742(5), b = 6.968(5), c = 10.777(6) Å, β = 104.6(6)°. The structure has been determined from single crystal X-ray data by means of Patterson and Fourier synthesis and refined to a final conventional R value of 0.037 using 1292 independent reflexions. The structure is built up of K⁺ and [SOC? OCH₃]^? ions. The potassium ion is bonded to four oxygen and four sulfur atoms from five oxoxanthate ions. The coordination polyhedron consists of two reciprocally penetrated and distorted O₄ and S₄ tetrahedra.     

Thiophene systems. 7. Pyrido[3,2-b]thieno[3,4-e][1,4]diazepine derivatives with potential cns activity

Pyrido[3,2-b]thieno[3,4-e][1,4]diazepines ( 1a-d ) were synthesized to investigate their potential CNS activity. Synthesis of the desired ring system was effected by condensation of 2,3-diaminopyridine ( 3 ) with methyl tetrahydro-4-oxo-3-thiophenecarboxylate ( 4 ). Structural assignment of the major condensation product 5 was determined by comparison of ¹H nmr absorptions of 5 with those of related methyl lactam derivatives 11 and 14. A discussion of the possible mechanism leading to 5 in preference to isomeric lactam 6 is presented. Biological evaluation of 1a-d revealed no interesting properties.     

Nitroazines. 19. Prototropic tautomerism in 6-nitro-7-oxo-4,7-dihydro-1,2,4-triazolo[5,1-c][1,2,4]triazines

Prototropic reactions of 6-nitro-7-oxo-4,7-dihydro-1,2,4-triazolo[5,1-c][1,2,4]triazines is tautomeric as established from photoionization results. The ratios of the tautomers in the gas phase and in solution have been determined by mass and ¹³C NMR spectroscopy.For Communication 18 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1555–1559, November, 1992.     

Reaction of 4,5-diamino-3-methyl-1-phenylpyrazole with 3-dimethylaminopropiophenones. Synthesis of new 4-aryl-6-methyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines and 4-aryl-8-methyl-6-phenyl-2,3-dihydropyrazolo[4,3-b]diazepines

New 4-Aryl-6-methyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines and 4-aryl-8-methyl-6-phenyl-2,3-dihydropyrazolo[4,3-b]diazepines were obtained from the reaction of 4,5-diamino-3-methyl-1-phenylpyrazole 1 with one equivalent of the 3-dimethylaminopropiophenones 2 in absolute ethanol. The structures of 4-aryl-6-methyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines 3 and 4-aryl-8-methyl-6-phenyl-2,3-dihydropyrazolo[4,3-b]diazepines 4 were determined by detailed nmr measurements.     

Esr and polarography of nitroazoles. 4. Polarographic study of nitrobenzimidazoles

The electrochemical reduction of 2-substituted 5(6)-benzimidazoles has been studied with the aid of classical polarography and cyclic voltammetry in acetonitrile. The influence of the substituents in position 2 on the magnitudes of the half-wave potentials of the first stage is exerted by induction and resonance mechanisms with approximately the same contributions, and that on the magnitudes of the half-wave potentials of the second stage predominantly by the resonance mechanism. The possibilities of taking the radical-stabilizing factor into account in the correlations are discussed. In order to study the 2-substituted 5(6)-nitrobenzimidazole series, their pK _a values in acetonitrile have been determined by potentiometric titration.For communication 3, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1246–1251, September, 1984.     

Bildung Siliciumorganischer Verbindungen. LV. Die Konformeren des 1,3,5,7-Tetrasila-bicyclo[3,3,1]nonans und 2,4,6,8,9-Pentasila-bicyclo[3,3,1]nonans

Formation of Organosilicon Compounds. LV. Conformeres of the 1,3,5,7-Tetrasilabicyclo [3,3,1] nonane and 2,4,6,8,9-Pentasila-bicyclo [3,3,1] nonane Two types of carbosilanes with a bicyclo [3,3,1] nonane structure are reported, derivatives of 1,3,5,7-Tetrasila-bicyclo-[3,3,1] nonane (a) and of 2,4,6,8,9-Pentasila-bicyclo [3,3,1] nonane (b) with an inverse structure in respect to the Si- and C-atoms. By means of NMR-investigations the structure can be determined. Derivatives of (a) are present in the Si₄C₁₁H₂₈ with fully methylated Si-atoms, the 1,5 dichloro-1,3,5,7-tetrasila-bicyclo [3,3,1] nonane and Si₄Cl₆C₅H₁₀ with fully chlorinated Si-atoms with twofold boat conformation. In the derivatives of type (b) as Si₅H₁₀C₄H₆ with hydrogenated Si-atoms as well as in 9,9-dichloro-2,4,6,8,9-pentasila-bicyclo [3,3,1] nonane a change in conformation is observed, whereas a rigid chair conformation is found for both rings in the Si-chlorimated derivative Si₅Cl₁₀C₄H₁₀. A comparison of atom-resp. H? H distances in cyclohexane and 1,3,5-Trisilacyclohexane gives evidence that the boat conformation is more preferable for the 1,3,5-Trisilacyclohexane than for cyclohexane due to larger H? H-distances (caused by Si? C-distances).     

The chemistry of 5-hydroxy-6-(hydroxyalkyl)uracils. Synthesis of spiro[pyrimidine-4,2′-pyrano[3,2-d]pyrimidines]

Both 5-acetoxy-6-(acetoxymethyl)-1-methyluracil 1 and its parent diol 11 are converted into the spiro[pyrimidine-4,2′-pyrano[3,2-d]pyrimidine] 6 when treated, respectively, with hot methanolic pyridine and with one equivalent of acetic anhydride. The formation of 6 can be explained in terms of the generation and dimerization of the reactive 5-oxo-6-methylene pyrimidine 2 . The structure of 6 was determined by ¹³C nmr spectroscopy and by chemical transformations that lead to the pyrimidinylethylhydantoin 9 and the 6,6′-[1,2-ethanediyl]bispyrimidine 10 . The more complex 5-hydroxy-6-(hydroxyalkyl)uracils represented by the 6,5′-cyclourid-ines 17 undergo an analogous dimerization when treated with acetic anhydride to give structures 22a and 22b . Dimer 22a was also prepared via the 5-phosphate ester 18 . The stereochemistry of dimers 22a and 22b , which is apparent from their ¹H nmr spectra, indicates that two molecules of the enones 21a or 21b dimerize in a highly stereoselective manner.     

Polyurethanes containing sulfur. II. New thermoplastic nonsegmented polyurethanes with diphenylmethane unit in their structure

New thermoplastic nonsegmented thiopolyurethanes were synthesized from the new low‐melting aliphatic‐aromatic thiodiols bis[4‐(2‐hydroxyethyl)thiomethylphenyl]methane, bis[4‐(3‐hydroxypropyl)thiomethylphenyl]methane, and bis[4‐(6‐hydroxyhexyl)thiomethylphenyl]methane and hexamethylene diisocyanate both by melt and solution polyaddition with dibutyltin dilaurate as a catalyst. All the thiodiols were prepared with high yields by the condensation reaction of bis(4‐mercaptomethylphenyl)methane with 2‐chloroethanol, 3‐chloro‐1‐propanol, or 6‐chloro‐1‐hexanol. The hard‐segment‐type polyurethanes obtained were plastic materials with partially crystalline structures. Polymerization in solution produced products with higher molecular weights (η_red = 0.97–1.24 dL/g) than polymerization in melt (η_red = 0.44–1.05 dL/g). The structures of all the polyurethanes were determined with elemental analysis, Fourier transform infrared, and X‐ray diffraction analysis. Thermal properties of the polymers obtained in solution were examined by differential scanning calorimetry and thermogravimetric analysis. Shore A/D hardness and tensile properties for all the polyurethanes were also determined. Of the two kinds, the polyurethanes obtained in solution possessed better tensile properties and showed yield stress (tensile strength) in a range of 27.8–30.0 MPa at an elongation of 17.4–25.1%. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1767–1773, 2000     

Indolizines. 6. Relative reactivities of isomeric 6-, 7-, and 8-ethoxycarbonylindolizine derivatives

The kinetics of the alkaline hydrolysis of 2-phenyl-6-, -7-, and -8-ethoxycarbonylindolizines were studied. The rate constants for the hydrolysis of these compounds and the indexes of the dissociation constants of 2-phenylindolizine-6-,-7-, and -8-carboxylic acids were determined by spectrophotometry. The indexes of the electronic structures and reactivities of 2-methyl-6-, -7-, and -8-ethoxycarbonylindolizines were calculated from theory.See [1] for Communication [5].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 627–633, May, 1979.     

Polymer reactions. VI. Inhibited autoxidation of polypropylene

The autoxidation of polypropylene inhibited by 2,6-di-tert-butyl-p-cresol (AH) and dilauryl thiodipropionate (S) was studied by the combined methods of electron spin resonance, oxygen absorption, and chemical analysis. With AH alone, there is a critical concentration of about 6 X 10^-3 mole/l. below which there is no inhibition. This critical concentration agrees with that determined for inhibited squalane autoxidation and that calculated from known rate constants. Above the critical concentration there is a well-defined induction period during which the ROO· concentration is estimated to be 10^-8 mole/l. [ROOH] decreased rapidly as did [A·] and [AH]; the latter are kinetically related. The rate constant for the reaction between A· and ROO· is estimated to be 7 X 10⁷ l./mole-sec. at 130°C. At the end of the induction period, [ROOH], [ROO·], and –d[O₂]/dt increased rapidly until steady-state values were attained for all of them. With S alone, there are only retarded oxidation but no well-defined induction periods. [ROOH] is greatly reduced by S. In all systems where the oxidation rates were appreciably suppressed there was formed a very stable paramagnetic species, S·, which was inert toward AH and I₂ but reactive toward triethyl phosphite. Because of its similarity with spin centers in carbon black, S· is postulated to be a delocalized polysulfide spin center. With both S and AH present, the combined effect of stabilization is synergistic. The observed time-dependent variations of [ROOH], [ROO·], and [A·] follow familiar mechanisms. Mathematical relationships describing each of these three systems are included.     

Macroheterocycles. 34. Synthesis and enantiomeric selectivity of chiral azacrown

Chiral azacrown ethers were obtained by the condensation of (4S,5S)-4,5-ditosyl-oxymethyl-2,2-dimethyl-1,3-dioxolane with 6-benzyl-3,9-dioxa-6-azaundecane-1,11-diol. Their debenzylation and deacetalization were realized. The enantiomeric selectivity in the complex formation between the obtained crown ethers and the hydrochlorides of L- and D-valine methyl esters was determined by a potentiometric method. The chiral azacrown ethers exhibit higher enantioselectivity than their oxygen analogs.See [1] for Communication 33.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 687–691, May, 1988.     

Investigation of phenanthridone and dioxotetrahydrodiazapyrene. 3. Investigation of the nitration of 5H-phenanthridin-6-one and its derivatives

The nitration of 5H-phenanthridin-6-one (I), 5H-phenanthridin-6-one-10-carboxylic (II) and 5H-phenanthridin-6-one-1-carboxylic acids (III), 4H-cyclopenta[k,l,m]-phenanthridine-5,9-dione (IV), 4H-cyclopenta[k,l,m]phenanthridine-5-one (V), 5,10-dioxo-4,5,9,10-tetrahydro-4,9-diazapyrene (VI), and 5,9-dioxo-4,5,9,10-tetrahydro-4,10-diazapyrene (VII) with nitric acid (sp. gr. 1.42–1.51) and a nitrating mixture of 0–120 °C was investigated. The orientation and sequence of incorporation of nitro groups in I-VII are determined by the presence of a phenanthridone structure in them. Mono-, di-, tri-, and tetranitro-substituted I-VII were obtained and characterized.See [l] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 388–393, March, 1981.     

Five-membered 2,3-dioxo heterocycles: LXXV. Reaction of methyl 1-aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates with 1,3-diphenylguanidine. Crystalline and molecular structure of 9-Benzoyl-8-hydroxy-2-imino-6-(4-methylphenyl)-1,3-diphenyl-1,3,6-triazaspiro-[4.4]non-8-ene-4,7-dione

Methyl 1-aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with 1,3-diphenylguanidine to give the corresponding 6-aryl-9-aroyl-8-hydroxy-2-imino-1,3-diphenyl-1,3,6-triazaspiro[4.4]non-8-ene-4,7-diones. The molecular and crystalline structures of 9-benzoyl-8-hydroxy-2-imino-6-(4-methylphenyl)-1,3-diphenyl-1,3,6-triazaspiro[4.4]non-8-ene-4,7-dione were determined by X-ray analysis.     

Synthetic transformations of higher terpenoids: XXIII. Synthesis of diterpenoid-based dihydroisoindolones

Vilsmeier-Haak reaction of phlomisoic acid methyl ester gave a mixture of 15- and 16-formyllabdanoids. In addition, methyl 2-formyldodecahydrophenanthro[1,2-b]furan-6-carboxylate was isolated, and its structure was determined by X-ray analysis. Reductive amination of 16-formyllabdanoid with benzylamine or α-amino acid methyl esters led to the formation of labdanoid furfurylamines which reacted with maleic anhydride to produce N-substituted 4-oxo-10-oxa-3-azatricyclo[5.2.1.0^1,5]dec-8-ene-6-carboxylic acids. Acylation of labdanoid furfurylamines with (E)-but-2-enoyl chloride afforded the corresponding unsaturated amides which were converted into 10-oxa-3-azatricyclo[5.2.1.0^1,5]dec-8-en-4-ones via intramolecular Diels-Alder reaction. Treatment of the oxa adducts with boron trifluoride-diethyl ether complex gave dihydroisoindol-1-one derivatives containing a diterpene fragment.     

Studies on the series of azoles and azines. 66. Synthesis,spectra and structure of 5-arylazo- and 5-arylideneamino-2,4,6-triaminopyrimidines and their 6-hydroxy analogs

5-Arylazo and 5-arylideneamino-2,4,6-triaminopyrimidines and their 6-hydroxy analogs were obtained by azo coupling of 2,4,6-triamino- and 2,4-diamino-6-hydroxypyrimidines with aryldiazonium salts, and also by the reaction of benzaldehydes with 2,4,5,6-tetraamino- and 2,4,5-triamino-6-hydroxypyrimidines, respectively. According to spectral data, in solvents with different polarity, these compounds exist preferentially in the triamino- or diaminohydroxy form. The main paths of the mass spectrometric fragmentation of the compounds studied have been determined.See [1] for Communication 65.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 659–667, May, 1988.     

Reactions with diazoazoles. Part VI. Unequivocal synthesis of 3-methyl-3h-azolotetrazoles. Correction of the formerly described 3-methylazolotetrazoles in favour of mesoionic 2-methylazolotetrazoles

3-Methyl-3H-pyrazolo[1,5-d]tetrazoles 2 and 3-methyl-6-phenyl-3H-1,2,4-triazolo[1,5-d]tetrazole (4) have been unequivocally synthesized by annulation of the tetrazole moiety to the pyrazole resp. 1,2,4-triazole system. The constitution of some N-methyl substituted azolotetrazoles, formerly described as 3-methyl-3H-pyrazolo[1,5-d]tetrazoles 2, 3-methyl-6-phenyl-3H-1,2,4-triazolo[1,5-d]tetrazole (4) and 1-methyl-6-phenyl-1H-1,2,4-triazolo[4,3-d]tetrazole (5), has to be revised in favour of the corresponding mesoionic 2-methyl derivatives 2′, 4′, 5′. The structures of 3-methyl-3H- as well as of 2-methyl-2H-pyrazolo[1,5-d]tetrazole derivatives 2a, 2c, 2′a have been determined by X-ray analyses. The azapentalenic system is aromatic in all three measured compounds and mesoionic in the case of the 2-methyl-2H- substitution pattern. The phenyl and ester substituents are coplanar with the azapentalene system. 3-, 2-, and 1-Methylpyrazolo[1,5-d]tetrazoles exhibit different behaviour when allowed to react with stannous chloride or sodium ethoxide. Azolotetrazoles with a methyl substituent at N-1, N-2 or N-3 of the tetrazole moiety can be distinguished by a combination of ¹H and ¹³C nmr with respect to the chemical shifts of the N-methyl group and the bridgehead carbon. Results of semiempirical calculations of the pyrazolo[1,5-d]tetrazole anion and of its N-methyl derivatives are discussed.     

A study of the catalytic reductive products of 2,3-dihydro-6-methoxy-3-(6-nitroveratrylidene)-4H-benzopyran-4-one. Part II

Although the previously reported (1,2) chemical reduction of 2,3-dihydro-3-(6-nitroveratry-lidene)-4H-benzopyran-4-one with stannous chloride occurred with cyclization to the 6H-[1]-benzopyrano [4,3-b]quinoline ring system, the present study of the catalytic (palladium/carbon) reduction of 2,3-dihydro-6-methoxy-3-(6-nitroveratrylidene)-4H-benzopyran-4-one ( 1 ) (3) has indicated that other products in addition to the expected benzopyranoquinoline ( 3 ) may be isolated, depending upon the conditions of the reduction. The products of the reduction of 1 , isolated and structurally determined, include 2,9,10-trimethoxy-6H-[1]benzopyrano-[4,3-b]quinoline(3),2,9,10-trimethoxy-6a,7,12,12a-tetrahydro-6H-[1]benzopyrano[4,3-b]-quinoline (2), the N-oxide of 3 (6 ), and 6-hydroxy-2,9,10-trimethoxy-6H-[l]benzopyrano-[4,3-b Jquinoline ( 8 ).