Saturated heterocycles. 136 . Synthesis of 2-substituted 2-azapyracridone derivatives

By means of Substitution, addition and condensation on the secondary nitrogen of 9-methyl-1,2,3,4-tetrahydro-2-azapyracridone (6) , twenty new azapyracridones were prepared.     

Saturated heterocycles. Part 216 . Synthesis,structure and ring opening of trans-perhydro-1,4-benzoxazepin-3-one derivatives

trans-Perhydro-1,4-benzoxazepin-3-ones 2a-c were synthesized and transformed to condensed-skeleton perhydro-trans-1,4-benzoxazepines 3a,b , the thiones 4a,b , the urea derivatives 5a,b , and N-acylated compounds 6a-e . Compounds 6b,d were ring-opened by hydrochloric acid in ethanol to yield trans-2-(1-carbethoxyethoxy)-1-acylaminomethylcyclohexane derivatives 7b,d . The ¹H- and ¹³C-nmr investigation and X-ray analysis of 5b and 6c,d proved that the expected N-acylated derivatives were formed and that both rings of the trans anellated compounds have a chair conformation.     

Saturated heterocycles,Part 172. Synthesis of 2,6-disubstituted-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine derivatives

The title compounds were synthesized via the addition of methyl acrylate to benzylamine or to α-aminopyridine, which gave the corresponding diesters, e.g. 12 , followed by Dieckmann condensation of the latter to yield the keto-esters 13 , which were condensed with amidines and guanidines, 3, 14 . Removal of the benzyl group by hydrogenolysis and subsequent alkylation of the nitrogen atom at position 6 in the resulting compound 5 , with variation of the substituents on C-2, gave a number of products with potential biological action; some of them gave analgesic and anti-inflammatory effects.     

Saturated heterocycles. 176 Synthesis and steric structure of quaternary azeto[2,1-a]isoquinoline stereoisomers

Starting from 1-substituted azeto[2,1-a]isoquinoline diastereomers, a number of quaternary salts were prepared. The reactions leading to the quaternary salts were stereospecific, independently of the configuration at C-1, resulting in diastereomers. The steric structures of the new compounds were proved by nmr spectroscopy.     

Saturated nitrogen-containing heterocycles. 13. Perhydroacridines. Synthesis and stereochemistry

The configurations of the perhydroacridines formed in the catalytic hydroamination of threo-methylenedicyclohexanone and the product of its cyclization — 2-hydroxy-2,3-tetramethylenebicyclo[3.3.1]nonan-9-one — were established by means of the ¹³C NMR spectra and alternative synthesis. It is shown that isomers with cis-anti-cis and cis-syn-cis configurations are formed as a result of the reactions. The results of x-ray diffraction analysis are presented for cis-syn-cis-N-(2-hydroxyethy1)perhydroacridine.See [1] for Communication 12.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1645–1650, December, 1987.     

Stereochemical studies. Part 67. Saturated heterocycles. Part 52. The mass spectra of some condensed skeleton 1,3-oxazin-4-one derivatives

The mass spectrometric behaviour of twenty saturated heterocyclic compounds with a 1,3-oxazin-4-one moiety fused with cis or trans anellation to a cycloalkane ring (C₅-C₈) was studied. The roles of the C-2 and N-3 substituent(s) were found to be characteristic, while the size of the cycloalkane ring seemed to be unimportant. Some fragmentation processes involving breakdown of the oxazinone ring of the cis or trans isomers displayed significant stereoselectivity. A striking new decomposition process involving significant chlorine elimination from the molecular ion of some 2-p-chlorophenyl derivatives was observed and was studied in some detail.     

Polycarbonyl heterocycles. Part III. Synthesis of 2,3-furanodione derivatives by ring transformations of thiazolidine-4,5-dione derivatives

The base catalyzed isomerization of 2-(aroyl-methylene)-3-aryl-thiazolidine-4,5-dione derivatives1 leads to salts of 1-aryl-3-aroyl-4-hydroxy-pyrroline-2-thio-5-one and aliphatic amines2. It was found that2 undergo further transformation to 4-thioanilido-5-arylo-2,3-furanodione derivatives4. This series of reaction provides a convenient synthetic route to 2,3-furanodione derivatives4.

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Polycarbonyl-Heterocyclen, 3. Mitt.: Synthese von 2,3-Furandion-Derivaten durch Ringtransformation von Thiazolidin-4,5-dion-Derivaten

Zusammenfassung Die basenkatalysierte Isomerisierung von 2-(Aroylmethylen)-3-aryl-thiazolidin-4,5-dionen1 führt zu Salzen von 1-Aryl-3-aroyl-4-hydroxy-pyrrolin-2-thio-5-on und aliphatischen Aminen2. Die letzteren gehen in 4-Thioanilido-5-arylo-2,3-furandion-Derivate4 über. Diese Reaktionsfolge stellte eine vorteilhafte synthetische Route zu 2,3-Furandionen dar.

     

Saturated nitrogen-containing heterocycles VI. Alkyl-2-thiopyrrolidones and their acetyl derivatives

A number of 5-alkyl-2-thiopyrrolidones and 1-methyl-5-alkyl-2-thiopyrrolidones were synthesized by the reaction of the corresponding pyrrolidones with phosphorus pentasulfide. The 5-alkyl-2-thiopyrrolidones were acylated.See [1] for communication V.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 333–335, March, 1972.     

Synthesis of isoquinoline alkaloid derivatives from eugenol

Alkylation under phase-transfer catalysis conditions (18-crown-6/KOH) of eugenol was used for cyclocondensation with nitriles (Ritter reaction), the products of which were isoquinoline derivatives.     

Saturated nitrogen-containing heterocycles. VIII. Synthesis and properties of some substituted pyrrolidylalkanols

Phenyl-substituted pyrrolidylalkanols were synthesized by hydrogenation of the corresponding furan amines in acidic aqueous solution in the presence of nickel on diatomaceous earth. Terephthalates, carbamates, and other pyrrolidylalkanol derivatives were obtained. The ability of (2-pyrrolidyl)-3-alkanols to form an intramolecular hydrogen bond was studied by IR spectroscopy.See [1] for communication VII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 186–190, February, 1976.     

Synthetic transformations of isoquinoline alkaloids. Synthesis of new dihydrothebaine-hydroquinone derivatives

1-Bromo-and 1-iodo-6,14-endo-ethenodihydrothebaine-hydroquinones were obtained. The Heck reactions of these halides with various olefins were studied. Dedicated to the memory of Academician N. N. Vorozhtsov on the 100th anniversary of his birth. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1206–1214, June, 2007.     

Synthesis of isoquinoline derivatives using ROM-RCM of cyclobutene-yne

Isoquinoline derivatives were synthesized from cyclobutenylmethylamine derivatives having an alkyne moiety in a tether using a second-generation ruthenium carbene complex under ethylene gas in good yields.     

Synthesis of novel isoquinoline derivatives as potential CNS-agents

A series of 4-aminomethyl-1,2,3,4-tetrahydroisoquinoline derivatives were prepared as potential CNS-agents acting via amino-acid neurotransmitter systems. The compounds were synthesized from 1,2,3,4-tetra-hydro-1-oxoisoquinoline-4-carboxylic acids obtained by dipolar cycloaddition reactions of imines with homo-phthalic anhydride. Among the compounds tested 5c and 5m showed sub-micromolar affinity for the NMDA receptor and represent a structurally novel class of ligand for this site.     

Synthesis of new fundamental heterocycles. Part VII. Synthesis of 2-azaxanthene

2-Azaxanthone ( 5 ) has been conveniently prepared by condensation of the morpholine enamine of 1-benzyl-4-piperidone witli salicylaldehyde followed by chromium trioxide oxidation and subsequent aromatization. Lithium aluminum hydride reduction of 5 afforded the new fundamental heterocycle 2-azaxanlhene.     

Saturated heterocycles, 248. Synthesis of 2,4-dioxo and 4-oxo-2-thioxo derivatives of octahydrocyclopenta[d]pyrimidines

Unsubstituted and 1-benzyl-substituted cis-cyclopenta[d]pyrirnidine-2,4-diones and cis-2-thioxo-cyclopenta[d]pyrimidin-4-ones 9a,b and 10a,b were prepared from the corresponding cis-2-amino-1-cyclopentanecarboxylates 3 and 5 with potassium cyanate and thiocyanate. It was found that the cis derivatives 7a-h readily underwent ring closure, resulting in 3-substituted cis-2,4-cyclopenta[d]pyrimidinediones and cis-2-thioxocyclopenta[d]pyrimidin-4-ones 11a-d and 12a-d , whereas the trans counterparts 8a-d failed to cyclize, but gave hydrolysed amino acid derivatives 13a,b and 14 . This difference in the reactivities of the cis and trans isomers is a further example of the difficulty of preparing cyclopentane trans-fused six-membered 1,3-heterocycles by ring closure.     

Synthesis of new polyaza heterocycles. Part 42: Diazines

Using Pd-catalyzed Stille cross-coupling reactions, we report here the synthesis of various mono- or bis(tri-n-butylstannyl)diazines which were reacted with various halogenated diazines to access to various polyaza heterocyclic derivatives.     

Synthesis of fluorescein derivatives containing metal-coordinating heterocycles

Fluorescein derivatives that contain Lewis basic heterocycles have been synthesized by concise reaction sequences. The preparation of these compounds proceeds by functionalization of an electron-rich aromatic precursor and subsequent condensation to form the fluorophore. These compounds are envisioned as components of metal-based sensors.     

Fused polycyclic nitrogen-containing heterocycles 14. Intramolecular cyclization of 4-azidocarbonyl-2,5-diphenylthiazole. New route to isoquinoline derivatives

Thermolysis of 2,5-diphenylthiazole-4-carboxylic acid azide is accompanied by intramolecular cyclization to form 2-phenyl-4-H-thiazolo[4,5-c]isoquinolin-5-one through intermediate 2,5-diphenylthiazol-4-yl isocyanate.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 436–439, February, 2005.     

Synthesis of heterocycles. Part V. The synthesis of substituted indenopyridines

2-Arylmethylene-l-indanones (I) and 2-arylmethylene-1,3-indanediones (VII) react with active methylene compounds in the presence of ammonium acetate as a basic catalyst to afford substituted pyridines. The postulated routes to the formation of the reported compounds are given.