Bridgehead Nitrogen Atoms Research Articles

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—XII : Configurational and conformational studies with perhydrocycloalkano [ e] pyrido [1.2- c] [1.3] oxazines

The four possible racemic isomers of perhydrobenzo [ e] pyrido [1.2- c] [1.3] oxazine, three isomers of perhydrocyclopentano [ e] and three isomers of perhydrocycloheptano [ e] pyrido [1.2- c] [1.3] oxazine together with some of their 4-methyl derivatives have been synthesized. Their configurations and preferred conformations have been assigned from a study of their NMR spectra and from an examination of their IR spectra in the 2700–2800 cm −1 region.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—XVI: Configurational and conformational studies with derivatives of 3-thia-1-aza bicyclo[4.4.0] decane

A series of substituted 3-thia-1-azabicyclo[4.4.0] decanes have been prepared and their configurations and preferred conformations about the ring fusion assigned from a study of their IR and NMR spectra. A comparison of the spectral data with that obtained on the corresponding 3-oxa-1-azabicyclo [4.4.0] decanes suggests marked deviations from the chair conformation for the 1,3-thiazane ring.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—XI : Configurational and conformational studies with derivatives of 1,3-diazabicyclo[4.4.0]decanes

The configurations and preferred conformations of a number of 1,3-diazabicyclo[4.4.0]decanes have been assigned on the basis of their NMR spectra. Dipolar interactions are shown to be important in determining the position of conformational equilibria.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms. IX Configurational and conformational studies with methyl‐substituted 8‐phenyl‐l,8‐diazabicyclo[4.3.0]nonanes

AbstractThe synthesis of a series of methyl‐substituted 8‐phenyl‐1,8‐diazabicyclo[4.3.0]nonanes is described. The preferred conformations of these compounds have been assigned on the basis of the 2850‐2500 cm−1 region of their infrared spectra and of the geminal coupling constant of the C‐9 methylene group.

Heterocyclic systems containing a bridgehead nitrogen atom. V. Reaction of 4,5,6,7-Tetrahydro-1H-diazepine-2-thiol with α-halo esters and with halo ketones

Heterocyclic systems containing a bridgehead nitrogen atom. V. Reaction of 4,5,6,7-Tetrahydro-1H-diazepine-2-thiol with α-halo esters and with halo ketones

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—X : Configurational and conformational studies with methyl substituted perhydropyrido [1,2-c]pyrrolo[2,1-e] imidazoles

A series of Me substituted perhydropyrido [1,2- c]pyrrolo [2,1- e] imidazoles have been synthesized and their configurations and preferred conformations assigned on the basis of the 2800–2700 cm −1 region of their IR spectra and from a study of their PMR spectra with particular reference to the geminal coupling constant of the C6 methylene protons. The influence of dipole interactions in determining conformational preferences in these compounds is discussed.

Gas chromatographic separation of tricyclic compounds with bridgehead nitrogen atoms

The diastereoisomeric mixtures of a series of unsubstituted and substituted perhydrodipyrido[1,2- c;2′,1′- e]imidazoles (I), perhydropyridol[1,2- c]pyrrolo[2,1- e]imidazoles (II) and perhydrodipyrido[1,2- c;2′1′- f]pyrimidines (III), have been separated by preparative gas-liquid chromatography. Correlations have been made between the retention times and stereochemistry of the isomers in each mixture.

Electronic structure and spectra of fused n/m ring systems with one or two bridgehead nitrogen atoms—IV: The pyrazolo[1.2 a]pyridazinium cation, the benzo(c)pyrazolo[1.2 a]cinnolinium cation and pyrrolo[1.2 f]phenanthridine

The π-electronic structures and absorption spectra of the pyrazolo[1,2- a]pyridazinium cation, the benzo(c)pyrazolo[1,2- a]cinnolinium cation and pyrrolo[1,2- f]phenanthridine were investigated by means of the semiempirical SCFMO-Cl method of Pariser-Parr-Pople. Discussions are given on the π-bonding situation, chemical reactivity, location and origin of the lowest excited states.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—V : Configurational studies on derivatives of 2,2′-dipiperidyl

A series of racemic 6-substituted perhydrodipyrido [1.2-c, 2′.1′-e] imidazoles have been prepared and their configurations and preferred conformations assigned on the basis of NMR and IR spectroscopy. The two racemic isomers of perhydrodipyrido [1.2-a, 2′.1′-c] pyrazine and their 6-oxo derivatives have also been studied.

Electronic structure and spectra of fused n/m ring systems with one or two bridgehead nitrogen atoms

Electronic structure and spectra of fused n/m ring systems with one or two bridgehead nitrogen atoms

Electronic structure and spectra of fused n/m ring systems with one or two bridgehead nitrogen atoms

The semiempirical ASMO-SCF-CI method has been applied to study the electronic structures and ultraviolet absorption spectra of the 4-azapentalenyl anion, 4,8-diazapentalene and related azaderivatives. The agreement between observed and calculated transition energies is, in general, satisfactory. Chemical reactivity and assignment of the observed bands are discussed.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—VI : Configurational and conformational studies with derivatives of octahydropyrido [1,2-c] 1,3-oxazines

The configurations and preferred conformations of some substituted octahydropyrido[1,2-c]1,3-oxazines have been deduced on the basis of NMR spectra and the 2700–2850 cm −1 region of the IR spectra. The configurations of (±) sedridin and (±) sedamin have been confirmed. The importance of dipole interactions in determining the preferred conformations of this system have been illustrated.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—IV : Configurational and conformational studies with methyl substituted 8-thia-1-azabicyclo [4.3.0] nonanes

The preferred conformations of a series of Me substituted 8-thia-1-azabicyclo[4.3.0]nonanes have been assigned on the basis of the 2700–2850 cm −1 region of the IR spectra and on the geminal coupling constants of the NCH 2S protons.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—VII: Configurational and conformational studies with substituted 1,8-diazabicyclo[4.3.0]nonanes

The configuration and preferred conformations of some 8-alkyl 1,8-diazabicyclo[4.3.0]nonanes and the corresponding 2-Me substituted compounds have been deduced on the basis of their NMR spectra.

Bicyclic pyrimidine derivatives with a bridgehead nitrogen atom—III

Abstract C-Alkyl-s-triazolo[4.3-a]pyrimidines are distinguished from the s-triazolo[1.5-a]pyrimidines by their UV absorption at longer wavelength. The UV spectra (at pH2 and pH10) also differentiate the isomeric s-triazolopyrimidones (hydroxy-s-triazolopyrimidines); this differentiation may be confirmed by the IR stretching frequency of the CO group. The isomeric N-alkyl-s-triazolopyrimidones are more readily distinguished by their IR spectra.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—VIII : Configurational and conformational studies with methyl substituted perhydrodipyrido [1.2-c. 2′.1′-e] imidazoles

A series of Me substituted perhydrodipyrido [1.2-c. 2′.1′-e] imidazoles have been synthesized and their configurations and preferred conformations assigned on the basis of their IR and PMR spectra.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—III : Configurational and conformational studies with Derivatives of 8-oxal-azabicyclo [4.3.0] nonane

Some Me substituted 8-oxa-1-azabicyclo[4.3.0] nonanes have been prepared and their configurations and preferred conformations assigned. The importance of geminal coupling constants in studying the conformations of these compounds is demonstrated.

Heterocyclic compounds with bridgehead nitrogen atoms. Part III. The formation of cyclopenta[c]quinolizines from 3-α-dimethyl-aminovinylindolizines and dimethyl acetylenedicarboxylate

2-Alkyl- and 2-aryl-indolizines react with NN-dimethylacetamide, in presence of phosphoryl chloride, to give 3-α-dimethylaminoethylideneindolizinium salts. The enamines derived from the salts by proton-loss react with dimethyl acetylenedicarboxylate in boiling toluene to give dimethyl cyclopenta[c]quinolizinedicarboxylates. The intermediate compounds in this rearrangement have been isolated and the substitution reactions of the cyclopenta[c]quinolizine nucleus have been studied.

307. Heterocyclic compounds with bridgehead nitrogen atoms. Part II. Condensation of diethyl β-oxoglutarate with electrophilic ethoxymethylene compounds; synthesis of a 6-hydroxyquinolizin-4-one

307. Heterocyclic compounds with bridgehead nitrogen atoms. Part II. Condensation of diethyl β-oxoglutarate with electrophilic ethoxymethylene compounds; synthesis of a 6-hydroxyquinolizin-4-one

INVESTIGATIONS IN HETEROCYCLES. XV. METHYLPHENDIATE: A VERSATILE INTERMEDIATE IN THE SYNTHESIS OF BICYCLIC HETEROCYCLES WITH A BRIDGEHEAD NITROGEN ATOM.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInvestigations in Heterocycles. XV. Methylphenidate: A Versatile Intermediate in the Synthesis of Bicyclic Heterocycles with a Bridgehead Nitrogen AtomGeorge DeStevens and Marcel BernierCite this: J. Med. Chem. 1964, 7, 2, 146–149Publication Date (Print):March 1, 1964Publication History Published online1 May 2002Published inissue 1 March 1964https://doi.org/10.1021/jm00332a006RIGHTS & PERMISSIONSArticle Views145Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (489 KB) Get e-Alerts Get e-Alerts