Synthesis of pyrazoles and oxyquinoxalines from 2,4-dioxohexenoales

Condensation of ethyl 2,4-dioxo-6-phenylhex-5-enoates (I; R = H, I; R = Me, I, R = Ph) with various hydrazines yielded ethyl 5-styrylpyrazole-3-carboxylates (III), which were hydrolyzed to the acids (IV), and ozonized to 5-keto pyrazole esters (VI) and acids (VII). Reduction of the 5-formylpyrazoles (VI; R = II) with borohydride afforded the 5-hydroxymethyl derivatives (VIII). The same 2,4-dioxohexenoates (I) when treated with o-phenylenediamine gave 2-oxy-quinoxalines (V; R = H, V; R = Me, V; R = Ph). The uv spectra data of these compounds are given.     

Cyclic silylamides of vanadium, niobium, tantalum and hafnium. Crystal and molecular structures of spirocyclic tetraamides of V, CH3Nb and Hf

The spirocyclic silylamides M[(NR)₂SiMe₂]₂ (R = t-Bu: M = Hf (III), V (IV); R = SiMe₃: M = V (V), NbCl (VI), TaCl (VII)) have been prepared by reaction of the HfCl₄, VCl₄, NbCl₅ and TaCl₅, respectively, with Me₂Si[N(Li)R]₂. Methylation of VI and VII with MeLi yields the respective NbCH₃ and TaCH₃ derivatives (VIII and IX). The effective magnetic moments of IV and V are 1.67 and 1.66 μ_B respectively. Infrared and Raman spectra are given, and the ¹H, ¹³C and ²⁹Si chemical shifts for the diamagnetic compounds are reported. Single-crystal X-ray studies have been performed on III, IV and VIII. The structures of III and IV possess distorted tetrahedral symmetry (D_2d), with mean M---N distance of 2.030(4) and 1.853(5) Å, respectively. Distorted trigonal-bipyramidal coordination with an equatorial methyl group is found for each Nb atom of the two crystallographically independent molecules of VIII. Mean Nb---C, Nb---N (equatorial) and Nb---N (axial) bond lengths are 2.218(9), 1.997(4) and 2.026(5) Å, respectively.     

A one-step synthesis of 2-methylthio-6-oxopyrimidine derivatives: Preparation of fused pyrimidinones

Condensation of a ternary mixture of ethyl cyanoacetate, S-methylisothiourea and aromatic aldehydes in pyridine afforded directly the 4-aryl-5-cyano-2-methylthio-6-oxopyrimidines IV in good yields. Alkylation of IV with alkyl halides in alkaline medium yielded the 1-alkyl derivatives V. The methylthio group in IV and V could be eliminated by aniline, hydrazine and phenylhydrazine and the corresponding 2-anilino, VII, 2-hydr-azino, VIIIa,b, and 2-phenylhydrazino, VIIIc,d, derivatives were obtained. Compounds VIIIa,b could be cyclised with nitrous acid to give the 3-cyano-4-phenyltetrazolo[1,5-a]pyrimidine-2-one (Xa) and the 1-methyl analogue Xb, respectively. Some derivatives of VIII were prepared to help in elucidating the structures.     

Mass spectrometric study of isatins II. N-propyl(allyl,propargyl)isatins

The mass spectra of N-propyl- (I), N-allyl- (IV), and N-propargylisatin (VII) and their 5-methyl (II, V, VIII) and 7-methyl (III, VI, and IX) derivatives were recorded. It is shown that a portion of the [M-2CO]⁺ ions in the mass spectra of N-propargylisatins undergo rearrangement to give ions with a quinoline structure. A scheme for the fragmentation of the investigated compounds is presented. The mass spectra of the 5- and 7-methyl derivatives are compared.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 639–641, May, 1977.     

Acetylenic ketones. Part VI. Reaction of aroylphenylacetylenes with hydrazine derivatives

The reaction of aroylphenylacetylenes (I) with acyl- or aroylhydrazines (II) gave ω-aroyl-acetophenone-N-acyl or N-aroylhydrazones (IV). The latter gave upon treatment with methanolic potassium hydroxide and with acetic anhydride in the presence of sodium acetate, the corresponding pyrazoles (V) and the N-acetylpyrazoles (VII and VIII), respectively. The acetylenic ketones ( 1 ) also reacted with methylhydrazine and 1,1-dimethylhydrazine to give 5-aryl-1-methyl-3-phenylpyrazoles (XII), and 1,1-dimethylhydrazine derivatives (XIII), respectively. When the latter compounds were heated with acetic anhydride, they gave the N-methylpyrazoles (XII).     

Bor-Stickstoff-Verbindungen,LXVII [1]. Zur Kenntnis Gemischter Amino-hydrazino-borane

Boron-Nitrogen Compounds. LXVII. Mixed Amino-Hydrazino-Boranes Mixed amino-hydrazino-boranes have been prepared by the reaction of 1,3-dimethyl-2-chloro-1,3,2-diazaboracycloalkanes with partially substituted hydrazines and by condensation of the corresponding 2-methylthio derivatives with hydrazine. The compounds I to VII were isolated; IV and V may also be viewed as diborylamines. Nuclear magnetic resonance and infrared spectroscopic data of the compounds are discussed.     

QUENCHING OF SINGLET MOLECULAR OXYGEN BY PHTHALOCYANINES AND NAPHTHALOCYANINES

Using the direct measurement of the photosensitized luminescence of singlet molecular oxygen (1O2) the rate constants (kq) have been determined for 1O2 quenching by the monomeric molecules of the following phthalocyanines and naphthalocyanines in chloroform: tetra-(4-tert-butyl) phthalocyanine (I); octa-(3,6-butoxy) phthalocyanine (II), tetra-(6-tert-butyl)-2,3 naphthalocyanine (III), aluminium tetra-(1-tert-phenyl)-2,3 naphthalocyanine (IV), tri-(n-hexyl-siloxy) derivatives of silicon- (V), tin- (VI), aluminium- (VII) and gallium- (VIII) 2,3 naphthalocyanine. The following kq values were obtained (kq x 10(-8) M-1 s-1): 2.9 (I), 59 (II), 100 (III), 20 (IV), 3.9 (V), 53 (VI), 33 (VII), 110 (VIII). As most of the quenchers have the low-lying triplet levels, a contribution of the quenching mechanism based on the energy transfer from 1O2 to these levels has been analysed. A formula is proposed describing the relation between kq values caused by this mechanism, and photophysical constants of the quencher triplet state. This formula was applied to phthalocyanines, naphthalocyanines, beta-carotene and bacterochlorophyll a. The data suggest that the energy transfer can fully explain the activity of V and strongly contributes into the activities of II, III and VI-VIII. A charge transfer interaction might be an additional mechanism involved in 1O2 quenching by compounds studied. As some phthalocyanines and naphthalocyanines are strong physical quenchers of singlet oxygen they can be used as efficient inhibitors for photodestructive processes in photochemical systems.     

Synthesis of novel thiazoles bearing hydrazine,thiosemicarbazide, thiazole,and thiazolidinone moieties

Thiazolecarboxylate esters (I) and (II) react with hydrazine hydrate to give the acid hydrazides (III) and (IV), which then react with KSCN and PhNCS to give high yields of the thiosemicarbazides (V)-(VIII). Cyclocondensation of the thiosemicarbazide (V) with 3-phenyl-3-chloro-2-oxopropionic acid derivatives gives compounds with two thiazole moieties (IX)-(XIV). The reaction of the phenylthiosemicarbazides (VII) and (VIII) with chloroacetyl chloride and (or) chloroacetic acid affords the thiazolidinonethiazoles (XV) and (XVI).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2832–2836, December, 1991.     

Preparation and some reactions of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5] undecane-3,9-disulfide

3, 9-Dichloro-2, 4, 8, 10-tetraoxa-3, 9-diphosphaspiro[5. 5]undecane-3,9-disulfide (I), has been synthesized by treating a dimethylacetamide solution of 2, 4, 8, 10-tetraoxa-3,9-diphosphaspiro[5. 5]undecane-3, 9-disulfide (III) with carbon tetrachloride. A number of other known methods for converting dialkyl phosphorothioites to thiophosphorochloridates were also applied to III, but all failed to produce I. Chlorination of either I or III gave an acyclic product, 4, 4-bis(chloromethyl)-1, 1, 7, 7-tetrachloro-2, 6-dioxa-1, 7-di-phosphaheptane-1, 7-dioxide (IV), in nearly quantitative yield. The same compound was also obtained by the previously known method of chlorinating 3, 9-dichloro-2,4,8,10-tetraoxa-3, 9-diphosphaspiro[5.5]undecane (II). The treatment of pentaerythritol with phosphorus pentachloride gave IV in minor amount along with a 25% yield of 4,4-bis-(chloromethyl)-1-chloro-2, 6-dioxa-1-phosphacyclohexane-1-oxide (VII). The hydrolysis of I in heated aqueous sodium carbonate gave, after acidification, 3,9-dihydroxy-2,4,8,10-tetraoxa-3, 9-diphosphaspiro[5. 5]undecane-3, 9-disulfide (VIII). A number of derivatives were prepared by reaction of I with phenoxides and amines. The corresponding thio-phosphorofluoridate XI was prepared by treatment of I with potassium fluoride in dioxane.     

Chemistry of 1,3-cyclohexanedione

Summary 1,3-Cyclohexanedione was alkylated with branched allyl bromides. The resulting 2-alkyl derivatives (IV), (V), and (VI), and also their enol acetates (VII), (VIII), and (IX), have an antihelminthic action. The highest antihelminthic activity is shown by the enol acetate (IX).     

Fluorocyclohexanes. Part XVII. Dehydrofluorinations of the cis and the trans isomers of 2H-1-(difluoromethyl)decafluorocyclohexane

2H-1-(Difluoromethyl)octafluorocyclohex-1-ene (I) and cobalt trifluoride at 165 °C afforded 2H-1-(trifluoromethyl)octafluorocyclohex-1-ene (IV) and four decafluorocyclohexane derivatives: the cis (III), and trans (V), -2H-1-(trifluoromethyl)-; the cis (VII), and trans (VI), 2H-1-(difluoromethyl) compounds. Dehydrofluorination of VII, using aqueous potassium hydroxide, gave only one alkene, 1-(difluoromethyl)nonafluorocyclohex-1-ene (VIII). In a slower reaction VI afforded two alkenes, mainly VIII, But also an isomer, 1-(difluoromethyl)nonafluorocyclohex-2-ene (IX) (ratio 2:1).     

Chemical Studies of Formosan Cobra (Naja naja atra) Venom. Part I. Chromatographic Separation of Crude Venom on CM-Sepadex and Preliminary Characterization of its Components

The crude venom of Formosan cobra (Naja naja atra) was separated into 12 fractions by CM-Sephadex (C-50) chromatography with ammonium acetate buffer by two-stage gradient elution. Fr. I was proved to be a mixture of nucleotides and nucleosides. The toxicity was found in Fr. VIII (neurotoxic), X (cardiotoxic), XI (cardiotoxic), and XII (cardiotoxic). Glycerophosphatase, alkaline phosphomonoesterase, and 5′-nucleotidase were found in Fr. III, V and IX, respectively. Phosphodiesterase was distributed in Frs. VI and VII, while lecithinase-A (phospholipase-A) was found in Frs. IV and V. Frs. VIII, IX and XII seem to be homogenous by the n-terminal analysis and the paper electrophoresis.     

Chemistry of fluorinated quinones I. The Diels-Alder reactions of fluoranil

The Diels-Alder reaction of fluoranil with cyclopentadiene, 1,3-butadiene, and 1-acetoxy-1,3-butadiene gave 1,4, 5, 8-bis(methylene)-4a, 8a, 9a, 10a-tetrafluoro-1, 4, 4a, 5, 8, 8a, 9a, 10a-octahydroanthraquinone (I), 2, 3, 4a, 8a-tetrafluoro-4a, 5, 8, 8a-tetrahydro-1,4-naphthoquinone (III), and 5-acetoxy-2, 3, 4a, 8a-tetrafluoro-4a, 5, 8, 8a-tetrahydro-1,4- naphthoquinone (VI), respectively. Hydrogenation of I gave the expected saturated diketone(II). Hydrogenation of III afforded, with elimination of the two tertiary fluorines, 2,3-difluoro-5, 6, 7, 8-tetrahydro-1, 4- dihydroxynaphthalene (IV). In hydrogenation of VI, acetic acid and two moles of hydrogen fluoride were eliminated to give 2,3-difluoro-1, 4-dihydroxynaphthalene(VII). Both dihydroxy compounds IV and VII yielded on oxidation with ferric chloride the corresponding quinones, 2, 3- difluoro-5, 6, 7, 8-tetrahydro-1, 4-naphthoquinone (V) and 2, 3-difluoro-1, 4-naphthoquinone (VIII), respectively. Equivalent amounts of compounds IV and V gave a red-brown semiquinone IX, and a mixture of VI and VIII gave a dark-violet semiquinone X.     

Henry condensation at high pressures

The hitherto inaccessible nitroolefin (VII), which is the most convenient intermediate for the synthesis of the psychotropic amine (VIII), has been obtained by the direct condensation at high pressures (up to 1500 MPa) of piperonal (V) with 1-nitropropane (VI). The structure of (VII) was confirmed by direct synthesis from pyrocatechol (X). The amine (VIII) was obtained in three steps from (VII). This synthesis of (VIII) is shorter than that previously reported.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 829–832, April, 1990.     

Isoquinoline derivatives VI. Synthesis and pharmacological properties of 4,6,7-substituted 1(2)-arylalkyl-1,2,3,4-tetrahydroisoquinolines and their analogs

The condensation of 6,7-dimethoxy-1,2.3.4-tetrahydroisoquinoline (II) with diphenylacetyl and diphenylpropionyl chlorides gave the corresponding amides (III). Reduction of III with lithium aluminum hydride converted them to tertiary amines IV, which were characterized as their hydrochlorides. The condensation of equimolecular amounts of amines I with the acid chlorides of substituted phenylacetic and diphenylpropionic acids gave amides V. The reduction of amides V with lithium aluminum hydride gave secondary amines VI. The corresponding tetrahydroisoquinolines (VII) were obtained by the cyclization of amides V and subsequent reduction with lithium aluminum hydride, The condensation of 1-diphenylethyl-6,7-dimethoxy-l,2,3,4-tetrahydroisoquinoline with formalin gave VIII. The IR spectra of the synthesized compounds were examined. The effect of these compounds on the arterial blood pressure and the coronary blood flow was studied.See [1] for communication V.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1683–1687, December, 1971.     

Synthesis of derivatives of pyrrolo[1, 2-α]pyrmidine

Continuing investigations in the field of the synthesis of condensed heterocyclic systems containing pyrrole and indole fragments ¦1–3¦, we have condensed of 2-aminopyrrole derivatives with various 1, 3-dicarbonyl compounds. The reaction took place at the boil in solutions in pyridine or acetic acid, and also without a solvent at 150–160° C, forming in a single stage derivatives of pyrrolo[1, 2-a]pyrimidine (I–III) and pyrrolo[2, 1-b]-tetrahydroquinazoline (IV–VI). The condensation of 2-aminopyrrole with acetoacetic and substituted acetoacetic esters led to 4-oxo derivatives of pyrrolo[1, 2-β]pyrimidine (VII and VIII).     

Some Novel Thiazoline and Thiazolidinone Derivatives Surmounted on Substituted Pyrazole Moieties as Potential Antipyretic Agents

Six novel series of substituted thiazoline (V, VI, VII and VIII) and thiazolidinone derivatives (IX and X) resulting from 2,3-dihydro-1, 5-dimethyl-3-oxo-2-phenyl-1H-pyrazole-4-carbaldehyde (I) and 1-phenyl-3-p-tolyl-1H-pyrazolc-4-carbaldehyde (II) were synthesized. The course of this synthesis included the preparation of two new scries of disubstituted thiosemicarbazone precursors (III and IV) which were cyclized with phenacyl bromide, ethyl 2-chloroacetoacetate as well as ethyl bromoacetatc to afford the target thiazolines and thiazolidinoncs. The antipyretic activity of some representative compounds was performed.     

Synthesis of Certain S-Triazole and s-Triazolo[3,4-B] 1,3,4-Thiadiazole Derivatives of Expected Pharmacological Activity

Reaction of the newly prepared 3-(2-thienyl)-4-amino-s-triazole-5-thione (I) with different alkyl kalides and aromatic aldehydes afforded the corresponding thioethers and arylidene derivatives (II and III), respectively. Attempt ring closure of (I) with acetic anhydride produced the unexpected triacetyl derivative (IV). The synthesis of certain 3-(2-thienyl)-6-substituted-s-triazolo[3,4-b] 1,3,4-thiadiazoles (V and VII) was described. IR, NMR and mass spectral analyses of the prepared compounds were discussed.     

Syntheses of derivatives of oestrane and 19-norsteroids from 6-methoxytetralone and 6-hydroxytetralone

The corresponding derivatives of Δ^{1,3,5(10),9,(11)}-8,14-seco- -homo-oestratetraen-3-ol-14,17a-dione(VII, VIII, IX) have been obtained by the condensation of 3-methoxy-, 3-hydroxy-, and 3-tetrahydropyranyloxy-1-vinyltetralols (IV, V, VI) with methyldihydroresorcinol. The diketones VIII and IX cyclize to form Δ^{1,3,5(10),8,14}- -homo-oestrapentaen-3-ol-17a-one (XIII), and the diketone (VII) may be converted, according to conditions, into 3-methoxy-Δ^{1,3,5(10),8,14}- -homo-oestrapentaen-17a-one (X), 3-methoxy-Δ_{1,3,5(10),9,(11)}- -homo-oestratetraen-14-ol-17a-one (XIV), and -homoequilenin (XI). Hydrogenation of the ketones X and XIII leads to the dihydroketones XV and XVI with a trans junction of the C and D rings. Reduction or hydrogen of XV gives the methyl ethers of -homo-oestrone and 8-iso- -homo-oestrone XIX and XVII which have been converted into the methyl ethers of (±)-oestrone and 8-iso-oestrone (XX and XXI). 19-Nor- -homotestosterone (XXV) and its methyl and ethyl analogues, which possess anabolic activity, have been obtained by a series of reactions from the ketones X and XV.     

Nucleophilic substitution in 1,2,3-thiadiazoles

By reactions of nucleophilic substitution of the halogen atom in 5-halo-1,2,3-thiadiazoles (IV), we have obtained 5-amino- (I, V), hydrazino-(VI, VII, IX, X), and mercapto- (VIII) 1, 2, 3-thiadiazoles. We show that upon reaction with amines, a mixture of 5-amino-1, 2, 3-thiadiazoles (I) and 5-mercapto-1, 2, 3-triazoles (II) is formed, and also the reaction product of compounds I and IV,: the selectivity of this process depends only on the type of solvent.Organic Synthesis Technology Department, Urals State Technical University—UPI, Ekaterinburg 620002. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 554–559, April, 1994. Original article submitted February 28, 1994.