Torp-Ziegler Cyclization in the Synthesis of 3-Amino-4-cyanopyrrole Derivatives

Polyfunctional derivatives of 3-aminopyrrole have been synthesized from several substituted -enamino nitriles using Torp-Ziegler cyclization. These compounds are starting materials for further conversions, particularly for the synthesis of pyrrolo[3,2-d]- and pyrrolo[3,4-d]pyrimidines.     

DMF acetals as alkylating and cyclizing agents: A facile route to substituted pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones

Summary Several 7-methyl-5-alkyl-2-vinylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones were prepared. The successful cyclization and alkylation of 6-(-methylbenzylidenehydrazino)-1-methyluracils2a–d using dimethylformamide acetals at high temperature provided6a–d,7a–d, and8a–d. Treatment of6a–d and7a–d with acid afforded 7-methyl-5-alkylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones9a,b; under the same conditions,3a–d reacted to 7-methylpyrazolo[3,4-d]-pyrimidine-4,6(5H)-dione (4) in good yield.

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DMF-Acetale als Alkylierungs- und Ringschlußreagentien: ein einfacher Weg zu substituierten Pyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dionen

Zusammenfassung Es wurden verschiedene 7-Methyl-5-alkyl-2-vinylpyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dione hergestellt. Cyclisierung und Alkylierung der 6-(-Methylbenzylidenhydrazino)-1-methyl-uracile2a–d mit Hilfe von Dimethylformamidacetalen bei hohen Temperaturen ergab6a–d,7a–d und8a–d. Behandlung von6a–d und7a–d mit Säure lieferte die 7-Methyl-5-alkylpyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dione9a,b; unter den gleichen Bedingungen reagierten3a–d in guter Ausbeute zu 7-Methylpyrazolo[3,4-d]pyrimidin-4,6(5H)-dion (4).

     

Thermal Behaviour of the Complexes of Zinc Amino Acids

The eight solid complexes of zinc with L--methionine or L--histidine were prepared. The thermal decomposition processes of these complexes were determined by means of TG-DTG. The results show that their decomposition processes can be divided into three steps except for the complex Zn(Met)₂ the decomposition of which is completed in one step. All the final products are ZnO.This revised version was published online in November 2005 with corrections to the Cover Date.     

Synthesis of β-D-xylofuranosyl- and 2,2′-anhydro-1-β-D-lyxofuranosylpyrimidine nucleosides

-D-Xylofuranosylpyrimidines were obtained by condensation of silyl derivatives of pyrimidines with 1,2-di-O-acetyl-3,5-di-O-benzoyl-D-xylofuranose with subsequent deprotection of the sugar fragment. Refluxing 2-O-tosyl derivatives of nucleosides with NaI results in the formation of 2,2-anhydro-compounds.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1137–1141, June, 1993.     

Reaction of 6-methyl-6-p-tolyl-4-ethoxy-5,6-dihydro-pyran-2-one1 with perchloric acid

6-Methyl-6-p-tolyl-4-ethoxy-5,6-dihydro-pyran-2-one (1) undergoes decarboxylative elimination with perchloric acid in ether to give 4-p-tolyl-3-penten-2-one (3), the structure of which has been confirmed through an unambiguous synthesis.

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Reaktion von 6-Methyl-6-p-tolyl-4-ethoxy-5, 6-dihydro-pyran-2-on mit PerchlorsäureKurze Mitteilung

Zusammenfassung Die Titelverbindung (1) ergibt mit Perchlorsäure unter decarboxylierender Eliminierung 4-p-Tolyl-3-penten-2-on (3). Die Struktur von3 wurde mittels eines eindeutigen Syntheseweges festgelegt.

     

Stereoselective synthesis of 2-deoxy-α-d-arabino-hexopyranosides of triterpene alcohols

2-Deoxy-2-iodo--d-mannopyranosides of triterpene alcohols of the oleanane series were synthesized inca. 60% yields by glycosylation with readily accessibled-glucal triacetate in the presence ofN-iodosuccinimide as the promotor. Their deiodination by catalytic hydrogenation followed by deacetylation yielded 2-deoxy--d-arabino-hexopyranosides of glycyrrhetic acid derivatives and allobetulin.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2340–2346, September, 1996.     

Synthesis of derivatives of 3-acetyl-2-aminopyrrole and pyrolo[2,3-d]pyrimidine from monoacetylketene aminals

A new scheme for the synthesis of pyrrolo[2,3-d]pyrimidines from monoacetylketene animals was proposed. Reactions of monoacetylketeneN-benzoyl- andN-acetylaminals with -bromoacetophenone afforded the corresponding 3-acetyl-2-acylamino-5-phenyl- lH-pyr-roles, which underwent cyclization to 2,4,6-trisubstituted 7Hl-pyrrolo[2,3-d]pyrimidines under the action of ammonium acetate in boiling BuOH.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp, 1808–1811, July, 19W     

Synthesis of 5′-amino- and 5′-azido-2′,5′-dideoxy nucleosides from thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione

Summary Thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (4) was silylated and condensed with methyl 5-azido-2,5-dideoxy-3-O-(4-methylbenzoyl)-D-erythro-pentofuranoside (2) in the presence ofTMS triflate to afford the corresponding protected nucleoside6 and acyclic nucleoside7. Deprotection of6 with MeONa/MeOH at room temperature gave 1-(5-azido-2,5-dideoxy--D-erythro-pentofuranosyl)-thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (8) and the corresponding anomer9, whereas compound7 yielded 5-azido-2,5-dideoxy-1-(2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidin-1-yl)-1-O-methyl-D-erythro-pentitol (10) under the same reaction conditions. 1-(5-Amino-2,5-dideoxy--D-erythro-pentofuranosyl)thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (11) was obtained on treating9 with Ph₃P in pyridine followed by hyrolysis with NH₄OH. The anomeric nucleosides14 and15 and the corresponding acyclic nucleoside16 were obtained when4 was trimethylsilylated and condensed with methyl 2-deoxy-3,5-di-O-(4-methylbenzoyl)-D-erythro-pentofuranoside (3) followed by deprotection with MeONa in MeOH. Compounds8 and9 were also obtained when the anomeric mixture14/15 was treated with a mixture of NaN₃, Ph₃P, and CBr₄ in dryDMF at room temperature.On leave from Chemistry Department, Faculty of Science, Tanta University, Tanta, Egypt     

Reactions of N-(2-chloroacetyl)-α-amino acids with 3-cyanopyridine-2(1H)-thiones. New promising route to 3,4-dihydropyrido[3",2":4,5]thieno[3,2-e][1,4]diazepine-2(1H),5-diones

The reactions of N-(2-chloroacetyl)--amino acids with 3-cyanopyridine-2(1H)-thiones afforded N-(3-aminothieno[2,3-b]pyridin-2-ylcarbonyl)--amino acids. Heating of the latter smoothly produced 3,4-dihydropyrido[3",2":4,5]thieno[3,2-e][1,4]diazepine-2(1H),5-diones in high yields.     

Addition of primaryN-nitroamides to activated olefins

PrimaryN-nitrosulfamides readily undergo addition to acrolein and vinyl ketones to yieldN--oxoalkyl-N-nitrosulfamides. The presence of a second substituent at the double bond hinders the reaction.N-Nitrourethane reacts with activated carbonyl compounds and -nitroolefins.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1261–1263, July, 1994.     

Strukturelle Abwandlungen anN-Acetylneuraminsäure, 3

From methyl-5-acetylamino-7,8-anhydro-4,9-O-bis-(t-butyldimethylsilyl)-3,5-dideoxy--D-glycero-D-galacto-2-nonulopyranosidonic acid methylester (1) the derivatives1 a and1 b were obtained by removing the 9-O-(t-butyldimethylsilyl)group withBu ₄NF, followed by acetylation. Treatment of1 b with 80% acetic acid and acetanhydride/pyridine yields the 8-epi-N-acetylneuraminic acid derivative2 a and the 7-epi-N-acetylneuraminic acid derivative3 a in a ratio of 3:1 (Scheme 1). The structure elucidation of2 b was achieved by converting2 b via the 4,9-bis-O-(tBDMSi)-8-O-tosyl-derivative2 d into the epoxide1 (Scheme 2). Using the same sequence the epoxides4 and5 were transformed into theN-acetylneuraminic acid derivative6 a and the 7,8-bis-epi-N-acetylneuraminic acid derivative7 a (Scheme 3). After treatment with sodium hydroxide and 0.025m HCl and Dowex 50 H⁺ the 8-epi-, 7-epi- and 7,8-bis-epi-N-acetylneuraminic acids2,3, and7 were obtained. These three compounds were tested withCMP-N-acetylneuraminic acid synthetase.

Herrn KollegenK. Schlögl mit den besten Wünschen zum 60. Geburtstag.     

Monolayer behaviors of poly(hexamethylene adipamide) at the air/water interface

Monolayer films on the neutral water substrate were obtained by spreadingN-trifluoroacetic anhydride (NTF)-modified nylon 66 or nylon 612 in chloroform solutions. Alternatively, monolayer films were obtained by spreading from nylon 66 solutions in the 31 mixture of benzene (B) and phenol (P). The temperatures studied are 10.3°, 14.7°C, and 19.4°C. The isothermss of surface pressure (), and surface moment () against surface area per residue (A) were determined. The -A isotherms of the NTF-modified nylon 66/chloroform and the nylon 66/BP were found to be an expanded type, while that of NTF-modified nylon 612/chloroform was of a condensed type. The NTF-modified nylon 66/chloroform solutions could yield well-spread films even higher concentrations than nylon 66/BP solutions. In the -A isotherms at 10.3° and 14.7°C, the surface moments are constant at 143 mD/residue for NTF-modified nylon 66/chloroform, and 340 mD/residue for nylon 66/BP until the surface area reaches where the -A isotherms show a transition point. After the transition point, the surface moments for both systems drop steadily. However, the surface moment at 19.4°C shows a maximum at the transition point. Possible configuration of the nylon 66 residue in monolayer is discussed.     

1,2-bis-Dipyrrinon-9-yl-ethene — a novelb-homo-verdian chromophore: the reaction of 9-methyl-10H-dipyrrin-1-ones with bromine

Summary Upon treatment of 9-methyl-10H-dipyrrin-1-ones with bromine in dichloromethane, red bile pigment derivatives were obtained in moderate yields. They were structurally assigned as 1,2-bis-dipyrrinon-9-yl-ethenes, which are examples of the hitherto unknownb-homo-verdins. In addition, the correspondingmeso-biliverdins-XIII could be isolated from the reaction mixture. The mechanistic aspects of the reaction are discussed.

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1,2-bis-Dipyrrinon-9-yl-ethen — ein neuerb-Homoverdinchromophor: Die Reaktion von 9-Methyl-10H-dipyrrin-1-onen mit Brom

Zusammenfassung Die Reaktion von 9-Methyl-10H-dipyrrin-1-onen mit Brom in Dichlormethan ergab in mäßigen Ausbeuten rotgefärbte Gallenfarbstoffderivate. Sie konnten strukturell als 1,2-bis-Dipyrrinon-ethene zugeordnet werden, die ein Beispiel für die bisher unbekanntenb-Homoverdine darstellen. Darüber hinaus konnten aus der Reaktionsmischung die entsprechenden Mesobiliverdine-XIII isoliert werden. Die mechanistischen Aspekte dieser Reaktion werden diskutiert.

     

Synthesis of Precursors of Heterocyclic cis-β-Amino Alcohols by Intramolecular Amidoalkylation of 4-Hydroxyoxazolidin-2-ones

The reaction of intramolecular amidoalkylation of 4-hydroxyoxazolidin-2-ones leads to formation of novel and rare heterocyclic systems: substituted 1,5,6,10b-tetrahydro[1,3]oxazolo[4,3-a]isoquinolin-3-ones, 3a,4,5,10b-tetrahydro[1,3]dioxolo[4',5':6,7]naphtho[1,2-d][1,3]oxazol-2(1H)-ones, and 5,6,10,10a-tetrahydro-1H-di[1,3]oxazolo[3,4-d:4,3-g][1,4]diazepine-3,8-diones. Mild reaction conditions and the simplicity of isolation of the compounds formed make it possible to obtain the indicated heterocycles in high yields.     

Schiff base derivatives of lanthanons-synthesis of La(III), Pr(III) and Nd(III) derivatives of β-ketoimines derived from 2,4-pentanedione

Reactions of the isopropoxides of some of the lighter lanthanons with bidentate -ketoimines, such asAAH-n-C₄H₉ andAAH-C₆H₅ (donor system: N,OH) and tridentate -ketoimines such asAA(CH₂CH₂)H₂ andAA(CH₂CHCH₃)H₂ (donor system: HO,N.OH) have led to products of the typesLn(O-i-C₃H₇)_3n (AA-R) _n ,Ln(Oi-C₃H₇) (AAR') andLn ₂(AAR')₃ [Ln=La(III), Pr(III) or Nd(III);n=1 or 2;R=-n-C₄H₉ or-C₆H₅ andR'=-CH₂CH₂-or-CH₂CHCH₃-]. Some undergo exchange reactions with an excess oftert-butanol, leading to the corresponding complexesLn(O-tert-C₄H₉)_3n (AA-n-C₄H₉) _n andLn(O-tert-C₄H₉) (AA-CH₂CH₂). All these have been characterised by elemental analysis, molecular weight determinations and their ir spectra. A thermogravimetric analysis of the diisopropoxy derivatives has also been carried out.

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Schiff-Basen Derivate von Lanthaniden-Synthese von La(III), Pr(III) und Nd(III) chelaten mit -Ketoiminen

Zusammenfassung Reaktionen von Lanthanid-Isopropoxiden mit zweizähnigen -Ketoiminen [AAH-n-C₄H₉ undAAH-C₆H₅; Donorsystem: N,OH] und dreizähnigen -Ketoiminen [AA(CH₂CH₂)H₂ undAA(CH₂CHCH₃)H₂; Donorsystem: OH, N,OH] führten zu Produkten vom, TypLn(O-i-C₃H₇)_3-n (AA-R) _n ,Ln(O-i-C₃H₇) (AAR') undLn ₂(AAR')₃ [Ln=La(III), Pr(III) oder Nd(III);n=1 oder 2;R=n-C₄H₉ oder C₆H₅ undR'=CH₂CH₂ oder CH₂CHCH₃]. Einige Komplexe unterliegen bei Behandlung mit einem Überschuß vontert-Butanol einer Austauschreaktion, die zu den entsprechenden Butoxid-Komplexen führt [Ln(O-tert-C₄H₉)_3-n , (AA-n-C₄H₉) _n undLn(O-tert-C₄H₉) (AACH₂CH₂)]. Alle Derivate wurden mittels Elementaranalyse, Molgewichtsbestimmung und IR-Spektroskopie charakterisiert. Eine thermogravimetrische Analyse der Diisopropoxi-Derivate wurde ebenfalls ausgeführt.

     

Reaction of 3-phenyl-5-aminopyrazole with carbon disulfide: A novel synthesis of 3-(3′-phenylpyrazol-5′-yl)-4-phenylpyrazol-2-thione as well as of pyrazolo[3,4-d]thiazole and pyrano[2,3-d]thiazole derivatives

Summary 3-Phenyl-5-aminopyrazole (1) reacts with carbon disulfide, followed byin situ reaction with -haloketones3a–c, to afford5,7a, and7b, respectively. Compounds5 and7 were further utilized for the formation of heterocycles and their fused derivatives.

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Reaktion von 3-Phenyl-5-aminopyrazol mit Schwefelkohlenstoff: Ein neue Synthese von 3-(3-Phenylpyrazol-5-yl)-4-phenylprazol-2-thion sowie von Pyrazolo[3,4-d]thiazol- und Pyrano[2,3-d]thiazolderivaten

Zusammenfassung 3-Phenyl-5-aminopyrazol (1) reagiert mit Schwefelkohlenstoff und anschließendin situ mit den -Halogenketonen3a–c zu5,7a und7b. Die Verbindungen5 und7 wurden weiter zu Heterocyclen und ihren kondensierten Derivaten umgesetzt.

     

Improved synthesis of 6-deoxy-1,2-O-isopropylidene-β-L-talofuranose and 6-deoxy-1,2-O-isopropylidene-β-L-idofuranose

Summary The key step in the preparation of 6-deoxy-1,2-O-isopropylidene--L-talofuranose (7) and 6-deoxy-1,2-O-isopropylidene--L-idofuranose (13) is the selective exchange of the 6-O-mesyl rest of 3-O-acetyl-5,6-O-dimesyl-1,2-O-isopropylidene--D-allofuranose (4) and 3-O-acetyl-5,6-O-dimesyl-1,2-O-isopropylidene--D-glucofuranose (10) by acetate group (potassium acetate/18-crown-6).

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Ein neuartiger und präparativ nützlicher Zugang zu 6-Desoxy-1,2-O-isopropyliden--L-talofuranose und 6-Desoxy-1,2-O-isopropyliden--L-idofuranose

Zusammenfassung Schlüsselschritt bei der Herstellung von 6-Desoxy-1,2-O-isopropyliden--L-talofuranose (7) und 6-Desoxy-1,2-O-isopropyliden--L-idofuranose (13) ist der selektive Austausch der primären Mesyl-Gruppe in 3-O-Acetyl-5,6-O-dimesyl-1,2-O-isopropyliden--D-allofuranose (4) und 3-O-Acetyl-5,6-O-dimesyl-1,2-O-isopropyliden--D-glucofuranose (10) durch den Acetat-Rest in Gegenwart von Kaliumacetat/Kronen-Ether.

     

A thermodynamic and structural study of the interactions of pyridino- and diketopyridino-18-crown-6 ligands with some primary organic ammonium cations

Equilibrium constant (K), enthalpy change (H), and entropy change (S) values have been determined calorimetrically at 25°C in 90%MeOH 10%H₂O (v/v) for the interactions of pyridino-18-crown-6 (P18C6) and diketopyridino-18-crown-6 (K₂P18C6) with perchlorate salts of ammonium, benzylammonium,-phenylethylammonium,-phenylethylammonium, and-(1-naphthyl)ethyl-ammonium cations. The crystal structure of the complex of P18C6 with benzylammonium perchlorate was determined by X-ray crystallography. The¹H 1D and 2D NMR spectra of some of these complexes were used to elucidate their structural features in solution. The logK values for the interaction of the ammonium cations with P18C6 are larger than those with K₂P18C6, probably due to the higher degree of structural flexibility of P18C6. Ligand K₂P18C6 displays appreciable - interaction with the-(1-naphthyl)ethylammonium cation, but not with the-phenylethylammonium cation.- interaction between ligand and cationSupplementary Data relating to this article are deposited with the British Library as Supplementary Publication No SUP 00000 (22 pages)     

Condensed thiazoles,I: Synthesis of 5,7-disubstituted thiazolo[4,5-d]pyrimidines as possible anti-HIV,anticancer, and antimicrobial agents

Summary A convenient and simple synthesis of 5-mercapto-3-phenyl-2-thioxo-2,3-dihydrothiazolo-[4,5-d]pyrimidin-7(6H-one(2) and its 5,7-dichloro (3), 5,7-diazido (4), 5,7-diamino (5), 5,7-dimerapto (6), 5,7-dimethylthio (7), and 6-methyl-5-methylthio (8) derivatives is described. The prepared compounds were screened for theirin vitro anti-HIV, anticancer, antibacterial and antifungal activities.

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Kondensierte Thiazole, 1. Mitt.: Synthese von 5,7-disubstituierten Thiazolo[4,5-d]pyrimidinen als potentielle anti-HIV, anticancerogene und antimikrobielle Verbindungen

Zusammenfassung Die Synthese von 5-Mercapto-3-phenyl-2-thioxo-2,3-dihydrothiazolo[4,5-d-pyrimidin-7(6H)-on (2) und seiner 5,7-dichloro-(3), 5,7-diazido-(4), 5,7-dimanio-(5), 5,7-dimercapto-(6), 5,7-dimethylthio- (7) und 6-methyl-5-methylthio-Derivaten (8) wird beschrieben. Die hergestellten Verbindungen wurden auf ihrein vitro anti-HIV, anticancerogenen, antibakteriellen und antimykotischen Aktivitäten geprüft.

     

Thermal behavior of poly(α-n-alkyl β-L-aspartate)s

A series of poly(-n-alkyl -L-aspartate)s (n being the number of carbon atoms in the linear alkyl side chain, withn=1, 2, 4, 6, 8, 12, 18 and 22), was studied by differential scanning calorimetry and thermogravimetric analysis. The effect of the length of the alkyl group on thermal properties such as stability, melting and crystallization of side chains, was investigated. For the polymers with n12, two endothermic peaks at T₁ and T₂ were detected separating three distinct phases A, B and C. The peak at T₁ corresponds to the melting of the crystallized paraffinic side chains (transition A-B), and the peak: at T₂ may be attributed to a transition (B-C), implying a liquid crystal phase.This work has been supported by DGICYT PB-93-0960 and PB-93-1241. F.L.-C. acknowledges financial assistance from the Venezuelan institutions Universidad de Los Andes and Fundayacucho.