Polyfunctional Pyrazoles. 2. 1-Aryl-3-benzoyl-4-formyl- and 4-Carboxypyrazoles

Cyclization of 1-phenylpropane-1,2-dione monoarylhydrazones under Vilsmeier-Haack conditions gave 1-aryl-3-benzoyl-4-formylpyrazoles which were converted to 1-aryl-3-benzoyl-4-carboxypyrazoles using potassium permanganate in aqueous pyridine medium.     

Isochinoline. 2. Mitteilung [1]. Die Alkoholyse von 1-Chlor-3-chlormethyl-4-methyl-isochinolin und von 1-Chlor-4-chlormethyl-3-methyl-isochinolin

Methanolysis and ethanolysis of 1-chloro-3-chloromethyl-4-methyl-isoquinoline yield respectively 3-methoxymethyl-4-methyl-isocarbostyril and 3-ethoxymethyl-4-methyl-isocarbostyril as main products, together with some 3-chloromethyl-4-methyl-isocarbostyril. By analogous reactions, 1-chloro-4-chloromethyl-3-methyl-isoquinoline yields 4-methoxymethyl-3-methyl-isocarbostyril and 4-ethoxymethyl-3-methyl-isocarbostyril.     

4-Hydroxy-2-quinolones. 3. Synthesis and physicochemical properties of 1-R-3-carbethoxy-4-hydroxy-2-quinolones

1-R-3-Carbethoxy-4-hydroxy-2-quinolones were synthesized by intramolecular cyclization of N-R-2-carbalkoxymalonanilic acids by the Dieckmann reaction. The possibility and advantages of conducting this reaction in aqueous medium were demonstrated. The mutually perpendicular orientation of the heterocyclic and aryl fragments was demonstrated for the 1-phenyl derivative by ESR spectroscopy.See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 636–639, May, 1992.     

Synthetische Juvenilhormone 3. Mitteilung. p-Substituierte 4-Phenyl-buten(1)-carbonsäurederivate

The syntheses of p-substituted 2-methyl-4-phenylbuten(1)-carboxylic acid derivatives are described, using Blanc's chloromethylation reaction, the Friedel-Crafts alkylation of unsaturated ketones or the Meerwein arylation; the formed intermediates react in subsequent steps to the title compounds.     

4H-3, 1-benzoxazines. 5. PMR and mass spectrometric study of 2,4-substituted 1,2-dihydro-4H-3, 1-benzoxazines

The formation of 2,4-substituted 1,2-dihydro-4H-3, 1-benzoxazines from tertiary o-aminophenylcarbinols and carbonyl derivatives has been demonstrated by means of PMR and mass spectrometry. Interconversion of the six-membered heterocycle of the half-chair half-chair type has been established on the basis of the PMR data when identical substituents are present in positions 2 and 4. The cisarrangement of the protons in the H-C₍₂₎-N-H fragment of the heterocycle has been determined. The general laws governing the initial fragmentation of 1,2-dihydro-4H-3, 1-benzoxazines under the effects of electron impact have been revealed.For Communication 4, see [1].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 101–108, January, 1990.     

Photochemische Reaktionen. 112. Mitteilung [1] Zur Photochemie α, β-ungesättigter γ, δ-Epoxyester. III. Ergänzende Untersuchungen zur Triplettreaktivität

On triplet sensitization (E)- 5 gives (Z)- 5 and isomerizes via C(δ), O-bond cleavage to the cyclobutanone 6 and the conjugated γ-ketoester 7 . - On singulet excitation 6 undergoes decarbonylation and yields the bicyclo [4.1.0]heptane 8 . However, on triplet sensitization 6 is converted to the isomeric tricyclononane 9 by a stereospecific oxa-di-π-methane rearrangement. The structure of 9 is determined by X-ray analysis of the p-nitrobenzoate 15: a = 10.573, b = 14.707, c = 13.494 Å, β = 112.40°, P2₁/n, Z, = 4.     

13C NMR Spectra of cyclic nitrones. 1. 2-substituted 4-methyl- and 4-phenyl-1-hydroxy-5,5-dimethyl-3-imidazoline 3-oxides

The introduction of an N-oxide oxygen atom into azomethines leads to an upfield shift of the signals for the carbon atom of the G=N group in the ¹³C NMR spectra by 30–33 ppm. This is consistent with the increase in the electron density on this atom. The signal of the nitrone carbon atom is observed in the region of 140–147 ppm, depending on the nature of the substituent at the C(₂) atom of the 3-imidazoline 3-oxide ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 247–251, February, 1985.     

Flavonoids. 41. Stereospecific synthesis of 2,3-dihydro-c-3-substituted-t-3-methyl-r-2-phenyl-4H-1-benzopyran-4-ones

The synthesis of 2,3-dihydro-t-3-mesyloxy-c-3-methyl-r-2-phenyl-4H-1-benzopyran-4-one (1) is described. The reaction of mesylate 1 with various nucleophiles, first of all O- and N-nucleophiles, yields the corresponding 2,3-dihydro-c-3-substituted-t-3-methyl-r-2-phenyl-4H-1-benzopyran-4-ones 2b, 7b, 9, 10, 12, 14 and 18 . Azide 14 is a useful intermediate for the synthesis of flavonoids 15–17 .     

Photochemische Reaktionen. 116. Mitteilung [1]. Notiz zur 1γ, δ*-induzierten Photospaltung von γ, δ-Epoxy-eucarvon

π, π*-Induced Photocleavage of γ, δ-Epoxy-eucarvone . On ¹π, π*-excitation 1 undergoes cleavage of the C, C-oxirane bond ( 1 → c ) and isomerizes to the bicyclic dihydrofurane compound 5 . In addition, 1 shows photocleavage of the C (γ), O-oxirane bond ( 1 → d ) and gives the isomers 2, 3, 6, 7 and 8. Furthermore, the cyclohexenone 9 and the cyclohexene-1, 4-dione 10 are formed presumably via an intermediate 13 , which could also arise from d. Besides these products the compounds 11 and 12 are obtained, which are photoproducts of 2 .     

4-Hydroxy-2-quinolones. 1. Efficient method for obtaining 3-alkyl-4-hydroxy-2-quinolones

3-Alkyl-4-hydroxy-2-quinolones were obtained in high yields via the Dieckmann intramolecular condensation of substituted malonic acid ethyl ester 2-carbalkoxyanilides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1533–1534, November, 1991.     

Stoffwechselprodukte von Mikroorganismen 74. Mitteilung [1]. Synthese des Ferrichroms. 1. Teil: (S)-α-Amino-δ-nitr-ovaleriansäure (δ-Nitro-L-norvalin)

(S)-α-Amino-δ-nitropentanoic acid (δ-nitro-L -norvaline), an intermediate of the total synthesis of ferrichrome, was synthesized starting from diethyl oxalate and γ-butyrolactone.     

Isochinoline. 1. Mitteilung. Über die Umlagerung von α, α-Dialkylhomophtalimiden zu Derivaten des 1-Chlor-3, 4-dialkyl-isochinolins

On reinvestigation of the reaction of wet phosphorus oxychloride with α,α-dimethylhomophthalimide, 1-chloro-3-chloromethyl-4-methyl-isoquinoline and 1-chloro-4-chloromethyl-3-methyl-isoquinoline were isolated as the main products (aside from some substances resulting from a redox disproportionation). The production of these two substances can be rationalized by assuming a mechanism in which the rearrangement product is a protonated derivative of 3,4-dimethylene-3, 4-dihydroisoquinoline. With α, α-diethyl-homophthalimide the only isolated product was a derivative of 1-chloro-3, 4-diethyl-isoquinoline, with a chlorine atom in β-position of one of the ethyl groups, while with α-methyl-α-benzyl-homophthalimide the isolated product was 1,3-dichloro-4-methyl-isoquinoline, i.e. elimination had taken place instead of rearrangement. Also these results are in agreement with the proposed mechanism.     

4-Functionally Substituted 3-Heterylpyrazoles: VII. 3-Aryl(heteryl)-1-phenyl-4-pyrazolecarbonyl Isothiocyanates

3-Aryl(heteryl)-1-phenyl-4-pyrazolecarbonyl isothiocyanates were synthesized by treatment of 3-aryl(heteryl)-1-phenyl-4-pyrazolecarbonyl chlorides with lead, sodium, or ammonium thiocyanate. Their reactions with amines, hydrazines, and acylhydrazines gave the corresponding thioureas and thiosemi- carbazides.     

4-Hydroxy-2-quinolones. 46. Esters of 1H-2-Oxo-4-hydroxy-3-quinolineacetic Acid

Different methods of synthesizing esters of 1H-2-oxo-4-hydroxy-3-quinolineacetic acid were studied. Results are given for tests of the anti-inflammatory activity of these products.     

1-Methyl-3-phenyl-4-aminodekahydrochinolin

Zusammenfassung Phenacetylcyclohexen wurde in dieMannichbase (II) und diese mittels Methylamin unter Umaminierung und Ringschluß in 1-Methyl-3-phenyldekahydrochinolon-(4) (III) übergeführt. Von den aus III erhaltenen 4 stereoisomeren Oximen (IV a-d) wurde IV c mit LiAlH₄ zu dem Amin V reduziert.