Furopyridines. XIX. Reaction of furo[2,3-b]-, -[3,2-b]-, -[2,3-c]- and -[3,2-c]pyridine with acetic anhydride

Acetoxylation of N-oxide of furo[2,3-b]- 2a , -[3,2-b]- 2b , -[2,3-c]- 2c and -[3,2-c]pyridine 2d with acetic anhydride afforded compounds substituted normally at the α- or γ-position to the ring nitrogen, 3a, 4a, 4b, 3d, 4d, 8 and 9 , and in addition compounds substituted on the furan ring, 5a, 6a, 5b, 6b, 7b, 5c and 7c which were unexpected compounds. The structures of these compounds were established from the ir, nmr and mass spectra, and x-ray crystal analysis of 5b .     

Pyrazines. 2ème communication [1]. II. Synthèse de dihydro-6,7-5H-cyclopenta[b]pyrazines alkylées

Alkyl-5H-6,7-dihydrocyclopenta[b]pyrazines are prepared by condensation of cyclopentenolones with alkylenediamines or of aliphatic α-diketones with 1,2-diaminocyclo pentanes. Products so obtained were dehydrogenated using palladium on activated charcoal, or copper chromite. NMR. and mass spectra are given for 21 bicyclic pyrazines and intermediates, and their IR. spectra are compared.     

[2.2. …] Metacyclophane

The synthesis of [2.2.2] metacyclophane (yield 7,5%), [2.2.2.2]metacyclophane (yield 1,7%), [2.2.2.2.2]metacyclophane (yield 5,1%), [2.2.2.2.2.2]metacyclophane (yield 3,1%) and [2.2.2.2.2.2.2.2]metacyclophane (yield 0,5%) by a WURTZ reaction with α,α'-dibromo-m-xylene is described. The structure of the new ring systems was confirmed by UV.-, NMR.- and mass spectra analyses. In connection with the resulting melting points and NMR.-spectra probable conformations of these higher ring systems are discussed.     

Furopyridines. XI. 13C NMR Spectra of 2- or 3-Substituted Furo[2,3-b]-, Furo[3,2-b]-, Furo[2,3-c]- and Furo[3,2-c]pyridine

The ¹³C nmr spectra of 2- or 3-monosubstituted furo[2,3-b]- 1a-1j , furo[3,2-b]- 2a-2j , furo[2,3-c]- 3a-3j and furo[3,2-c]pyridine derivatives 4a-4j are reported. Effects by change in annelation and substituent effects on ¹³C chemical shifts and carbon-proton coupling constants are discussed. The spectra of benzo[b]furan derivatives 5a-5j having the corresponding substituent are also reported for comparison.     

Electron ionization mass spectra and crystal structures of some [1,2,4]triazolo[1,2-b]- and [1,3,4]thiadiazolo[3,4-b]phthalazines

The mass spectra of ten 1,3-dithioxo[1,2,4]triazolo[1,2,-b]phthalazines, five 3-iminosubstituted 1-thioxo-[1,3,4]thiadiazolo[3,4-b]phthalazines, three 3-iminosubstituted-1-thioxo[1,2,4]triazolo[1,2-b]phthalazines, and 1,3-dithioxo-5,10-dihydro[1,3,4]thiadiazolo[3,4-b]phthalazine were recorded under electron ionization. The fragmentation pathways were elucidated by metastable ion analysis and exact mass measurements. The changes in the ring-system had little effect on the fragmentation mechanism, but the effect on peak intensities was considerable. The most important fragmentations began with the opening of the triazole ring. Substituents at nitrogen atoms also had a marked effect on the mass spectral behavior. The aryl substituents prompted a whole new fragmentation. The X-ray crystal structure was determined for a few compounds. Two of the three structures of the 1,3-dithioxo[1,2,4]triazolo[1,2-b]phthalazines that were studied proved to be relatively planar, whereas the structure of 1,3-dithioxo-5,10-dihydro[1,3,4]thiadiazolo[3,4-b]phthalazine was considerably bent similarly to the 2-(4-chlorophenyl)-1,3-dithioxo-2,3,5,10-tetrahydro[1,2,4]triazolo[1,2-b]-phthalazine. The triazole and the thiadiazole rings had a strong double bond nature.     

Furopyridines. XXIII. Synthesis and reactions of chloropyridine derivatives of furo[2,3-b]-, -[2,3-c]- and -[3,2-c]pyridine

Chlorination of the N-oxides of furo[2,3-b]- 1a , -[2,3-c]- 1b and -[3,2-c]pyridine 1c with phosphorus oxychloride afforded compounds substituted normally at the α- or λ-position to the ring nitrogen, 2a, 2′a, 2b, 2c, 2′c and 2′c , and in addition, in the case of 1b , compounds substituted on the furan ring, 2′b and 2″b . The structures of these compounds were confirmed from their ir, nmr and mass spectra. The major chlorinated products 2a, 2b and 2c were converted to methoxy- 5a, 5b and 5c , N-pyrrolidyl- 7a, 7b and 7c , and phenylthiofuropyridines 8a, 8b , and 8c .     

Synthese von 1, 2-Dimethyl-phenanthro[1,2-b]furan und 1-Äthyl-2-methyl-phenanthro[1,2-b]furan. Furanabkömmlinge, 26. Mitteilung

We describe here the synthesis of 1,2-dimethyl-phenanthro [1,2-b] furan ( 11 ) and 1-ethyl-2-methyl-phenanthro [1,2-b] furan ( 13 ). The starting material was the known ethyl 2-methyl-phenanthro [1,2-b] furan-1-carboxylate ( 4 ). The two synthetized substances were characterized by their UV.-, IR.-, NMR.- and mass spectra, and identified with two products obtained by selenium dehydrogenation of anhydrohirundigenin.     

Pyridyl-substituted [1,3]Dithiolo-[4,5-<Emphasis Type="Italic">b</Emphasis>][1,4]dithiine-2-thiones

We have obtained 5-(2-pyridyl)[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione for the first time by cycloaddition of 2-ethynylpyridine to 4,5-dihydro-1,3-dithioltrithione (isotrithionedithiol). We have studied this thione, 5-(2-pyridyl)- and 5-(4-pyridyl)-5,6-dihydro[1,3]dithiolo[4,5-b][1,4]dithiine-2-thiones by mass spectroscopy and also IR, UV, ¹H and ¹³C NMR spectra. We have determined the crystal and molecular structure of 5-(2-pyridyl)-5,6-dihydro[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 429–434, March, 2005.     

BIRCH-Reduktion von [2.2] Metacyclophan

Metal-ammonia-reduction of [2.2] metacyclophan led to 5, 8, 13, 16-tetrahydro-[2.2] metacyclophan (II). The structure of this new ring system was confirmed by UV.-, NMR.-and mass spectra analyses. The NMR.-spectrum of II in solution shows an AA′ BB′-system for the -CH₂CH₂-groups. This part of the spectrum is temperature dependant. It collapses and coalesces to a broad singlet at approximately 145°C. A chair-like conformation and conformational changes of II are discussed.     

1,4-Dihydro-1λ5,4λ5-[1,4]diphosphinine und ein 1,4-Dihydro-1λ3,4λ3-[1,4]diphosphinin

1,4-Dihydro-1λ⁵,4λ⁵-[1,4]diphosphinines and a 1,4-Dihydro-1λ³,4λ³-[1,4]diphosphinine Reaction of thio- or dithiocarbonic acids with ethinyl amino phosphanes leads to 1,4-dihydro-1λ⁵,4λ⁵-[1,4]diphosphinine-1,4-disulfides. By this route compounds 4, 7 , and 8 have been prepared. Desulfurization of 4 with tri-n-butylphosphane results in 1,2,4,5-tetraphenyl-1,4-dihydro-1λ³,4λ³-[1,4]-diphosphinine 5 , which can be oxidized with tert-butyl-peroxide to the corresponding dioxide, 6 . From the reaction mixture of phenyl-phenylethinyl diethylamino phosphane and thioacetamide compound 4 and the unsymmetrical 1,4-dihydro-1λ⁵,4λ⁵-[1,4]diphosphinine 9 were isolated. Properties, nmr, ir and mass spectra of all new products are reported. A mechanism for the formation of 9 is suggested. The results of the X-ray structure determination of 8 and 9 are described.     

Electron impact mass spectrometry of isomeric [(5-N-methyl) and (12-N-methyl)]-11-(o- and p-R-aniline)-5H-dibenzo [b,e] [1,4]diazepines

The mass spectra of twelve isomeric [(5-N-methyl) and (12-N-methyl)]-11-(o- and p-R-aniline)-5H-dibenzo [b, e] [l,4]diazepines which have potentially useful pharmacological properties are presented.     

Stereoselektive Umwandlung von [2.2.2.2.2.2]Metacyclophan in ein all-trans-Hexaen

Starting from [2.2.2.2.2.2]metacyclophane the synthesis of [2.2.2.2.2.2]metacyclophane-all-trans-hexaene via dodecabromo-[2.2.2.2.2.2]metacyclophane is described. The structure of the new ring system was confirmed by UV.-, IR.-, NMR.-, and mass spectra analyses.     

Hydrogénation de sels de flavylium: formation de composés heptacycliques; structure radiocristallographique du [tétrahydro-10b,10c,16,16a-diméthyl-16,16a-méthylène-10b,16-5aH-di(benzo[1]pyranno)[4,3-b:3′,4′,-c;2,3:2′,3′]-benz[1]oxépinyl-5a]-2-phénol

Hydrogenation of Flavylium Salts: Formation of Heptacyclic compounds; X-Ray Crystal Structure of 2-[10b,10c,16,16a-Tetrahydro-16,16a-dimethyl-10b,16-methylene-5aH-di[1]benzopyrano[4,3-b:3′,4′ -c; 2,3:2′,3′][1]benzoxepin-5a-yl]phenol The hydrogenation of flavylium salts 1 either by catalytic reduction or by chemical reduction afforded the unexpected heptacyclic compound 2 , the structure of which was determined by X-ray analysis. The latter was confirmed by ¹H-NMR and mass spectra.     

Pyrrolothienopyrazines. IV. Synthese de derives de 1′amino-5 pyrrolo[1,2-a]thieno[2,3-e]pyrazine

5-Aminopyrrolo[1,2-a]thieno[2-3-3]pyrazine derivatives were obtained by intramolecular cyclisation of N³(1-pyrrolyl)-2-thienylurea derivaties. Synthesis of these latter compounds was achieved from 2-(1-pyrrolyl)-3-thenoylazide via a curtius rearrangement. The H nmr spectra are discussed.     

The synthesis of novel polycyclic heterocyclic ring system via photocyclization. 18. Benzo[h]naphtho-[1′,2′:4,5]thieno[2,3-c]quinoline and benzo[h]naphtho-[1′,2′:4,5]thieno[2,3-c] [1,2,4]triazolo[4,3-a]quinoline

The synthesis of two previously unknown polycyclic ring systems, benzo[h]naphtho[1′2′:4,5]-thieno[2,3-c]quinoline ( 1 ) and benzo[h]naphtho[1′,2′:4,5]thieno[2,3-c][1,2,4]triazolo[4,3-a]quinoline ( 2 ), was achieved via oxidative photocyclization of 1-chloro-N-(1-naphthyl)naphtho[2,1-b]thiophene-2-carboxamide ( 5 ). The total assignment of their ¹H and ¹³C nmr spectra was determined by the concerted use of two-dimensional nmr methods.     

Structural characterization of 1,3,4-thiadiazolo[3,2-a][1,3,5]triazines by electron impact mass spectrometry

The electron-impact-induced fragmentation of eleven 1,3,4-thiadiazolo[3,2-a][1,3,5]triazines was investigated with the aid of exact mass measurements, B/E and B²/E linked scans, and deuterated compounds. The dominating breakdown process in the electron impact mass spectra of 2-substituted 6-phenyl-1,3,4-thiadiazolo[3,2-a]-[1,3,5]triazine-5,7-diones (1–5) is a retro-Diels-Alder reaction. This process gives rise to the base peak, whereas the molecular ions are of very low intensity. In the mass spectra of 2-substituted 7-methylthio-1,3,4-thiadiazolo-[3,2-a][1,3,5]triazine-5-ones (6–11) in which this fragmentation cannot occur because of the two conjugated double bonds in the triazine ring, the molecular ions are very intense. The mass spectral data permits an unequivocal structure assignment to these compounds, which are otherwise difficult to characterize.     

The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 5. [1]Benzothieno[2,3-c]naphtho[2,1-f]-quinoline and [1]benzothieno[2,3-c]naphtho[1,2-g]quinoline

Two previously unknown heterocyclic ring systems, namely, [1]benzothieno[2,3-c]naphtho[2,1-f]quinoline ( 4 ) and [1]benzothieno[2,3-c]naphtho[1,2-g]quinoline ( 5 ) were synthesized via photocyclization of 3-chloro-N-(2-phenanthryl)benzo[b]thiophene-2-carboxamide ( 8 ) followed by chlorination and dechlorination. The total assignment of their ¹H- and ¹³C-nmr spectra was determined by utilizing inverse-detected HMQC and HMBC two-dimensional nmr spectroscopic methods.     

Convenient synthesis of novel pyrimido[4,5-b][1,5]benzothiazepines

Reaction of 4,6-dichloropyrimidine-5-carbaldehyde with amines in chloroform gave 4-(substitutedamino)-6-chloro-pyrimidine-5-carbaldehydes derivatives at low temperature. Treatment of the latter products with 2-aminobenzenethiol in alkaline benzene and then in boiling acetonitrile gave a novel group of 11H-pyrimido[4,5-b][1,5]benzodiazepine derivatives. Structures of the products confirmed by ¹HNMR, IR, and mass spectra.     

1,4-Cycloaddition reactions. III. Synthesis of furo[3,2-c]pyrido[2,3-g]quinolines,Furo[2,3-a] [4,7]phenanthrolines,Furo[3,2-c]pyrrolo[2,3-g]quinolines,Furo[3,2-c]pyrrolo[3,2-g]quinolines,and Furo[3,2-c]furo[2′,3′:4,5]pyrido[2,3-g]quinolines from 2,3-dihydro-5-methylfuran and schiff bases

The 1,4-cycloaddition of 2,3-dihydro-5-methylfuran (II) to 1-acetyl-1,2,3,4-te trahydro-6-[(p-hydroxybenzylidene)amino]quinoline (VIII) in the presence of boron trifluoride gave two pairs of epimers, namely dl-10-acetyl-2,3,3a,4,5,7,8,9,10,11b-decahydro-4-(p-hydroxyphenyl)-11b-methylfuro[3,2-c]pyrido[2,3-g]quinoline (IXa and b) and dl-8-acetyl-2,3,3a,4,5,8,9,10,11,-11c-decahydro-4-(p-hydroxyphenyl)-11c-methylfuro[2,3-a][4,7]phenanthroline (Xa and b). dl-9-Acetyl-3,3a,4,5,7,8,9,10b-octahydro-4-(p-hydroxyphenyl)-10b-methyl-2H-furo[3,2-c] pyrrolo-[2,3-g]quinoline (XIIIa) was the predominant product isolated from the reaction of II with 1-acetyl-5-[p-(hydroxybenzylidene)amino]indoline (XII). When 1-acetyl-6-[(p-hydroxybenzylidene)amino]indoline (XVI) was treated with 2,3-dihydro-5-methylfuran (II), two epimers of dl-7-acetyl-3,3a,4,5,7,8,9,10b-octahydro-4-(p-hydroxyphenyl)-10b-methyl-2H-furo[3,2-c]pyrrolo[3,2-g]quinoline (XVIIa and b) were obtained. dl-2,3,3a,4,5,6b,8,9,9a,10,11,12b-Dodecahydro-4,10-bis(p-methoxyphenyl)-6b,12b-dimethylfuro[3,2-c]furo[2′,3′:4,5]pyrido[2,3-g]quinoline (XX) was formed when 2,3-dihydro-5-methylfuran was allowed to react with N,N'-bis(p-methoxybenzylidene)-p-phenylcnediamine (XIX). Structure assignments were made from NMR spectra. None of the compounds exhibited appreciable biological activity.     

1,4-Cyeloaddition reactions. IV. preparation of Cyclopenta[g]furo[3,2-c]quinolines,Cyclopenta- [f]furo[3,2-c]quinolines,Benzo[H]furo[3,2-c]quinolines,and Furo- [3,2-c]indeno[1,7-gh] quinolines from 2,3-Dihydro-5-methylfuran and schiff bases

The boron trifluoride catalyzed 1,4-addition of 2,3-dihydro-5-methylfuran to N-(p-methoxybenzylidene)-5-indanamine (VI) gave 2 pairs of epimers, dl-3,3a,4,5,7,8,9,10b-octahydro-4-(p-methoxyphenyl)-10b-methyl-2H-cyclopenta[g]furo[3,2-c]quinoline (VIIa and b) and dl-3,3a, 4,-5,8,9,10,10c-octahydro-4-(p-methoxyphenyl)-10c-methyl-2H-cyclopenta[f]furo[3,2-c]quinoline (VIIIa and b). When 4-(benzylideneamino)-1-naphthol (IXa) was condensed with 2,3-dihydro-5-methylfuran in an analogous manner, a mixture of two isomers of dl-1,2,2a,3,4,5a-hexahydro-5a-methyl-2-phenylbenzo[h]furo[3,2-c]quinolin-7-ol [Xa and b (R ? H)] was obtained. Likewise, 4-[(p-hydroxybenzylidene)amino]-1-naphthol (IXb) and 4-(p-methoxybenzylidene)amino]-1-naphthol (IXc) gave a mixture of two isomers of dl-1,2,2a,3,4,5a-hexahydro-2-(p-hydroxyphenyl)-5a-methylbenzo[h]furo[3,2-c]quinolin-7-ol [Xa and b (R ? OH)] and dl-1,2,2a,3,4,5a-hexahydro-2-(p-methoxyphenyl)-5a-methylbenzo [h]furo[3,2-c]quinolin-7-ol [Xa and b (R ? OCH₃)], respectively. The condensation of N-(p-methoxybenzylidene)-5-acenaphthenamine (XI) with 2,3-dihydro-5-methylfuran afforded a mixture of two isomers of dl-2,3,3a,4,5,9,10,-11b-octahydro-4-(p-methoxyphenyl)-11b-methylfuro[3,2-c]indeno[1,7-gh]quinoline (XIIa and b). Structural assignments for all of the products were made from NMR spectra. None of these compounds possessed appreciable biological activity.