Organocatalytic Formal Intramolecular [3+2]-Cycloaddition to Acquire Biologically Important Methanodibenzo[a,f]azulenes and Methanobenzo[f]azulenes

Lawsones were transformed into the functionally rich framework of methanodibenzo[a,f]azulenes and methanobenzo[f]azulenes in a single- or two-pot operation through five organocatalytic sequential reactions in very good yields with excellent selectivities. These resultant molecules are basic skeletons of important antibiotics, which highlights the value of this formal intramolecular [3+2]-cycloaddition as a key protocol.     

Synthesis of derivatives of the new heterocyclic systems benz[f] imidazo [2,1 -a ] isoquinoline and benz [f] pyrimido [2,1 -a] isoquinoline

The synthesis of several derivatives of benz [f] imidazo [2,1 -a] isoquinoline and benz [f] pyrimido-[2,l-a]isoquinoline, both new heterocyclic structures, is described.     

Synthèses de la benzo[b][1,4]diazocino[7,6-f]indole,de pyrrolo[f]phtalazines et réactions de cycloadditions

From l-methyl-5,-dibenzoyl-1H-indole two new ring system, mainly a benzob[b][1,4]diazocino[7,6-f]indole and a pyrrolo[2,3-f]phthalazine are obtained. From 2-methyl-5,6-dibenzoyl-2H-isoindole a pyrrolo[3,4-f]phthalazine is obtained and the cycloaddtion reations with electron deficient dienophiles have been investigated.     

Synthesis of New 3-Aryl-1-methylbenzo[f]quinolines

Three-component condensation of 2-aminonaphthalene, acetone, and substituted benzaldehydes in alcoholic solution in the presence of concentrated hydrochloric acid gave 3-aryl-1-methylbenzo[f]quinolines. 1-Methyl-3-(nitrophenyl)benzo[f]quinolines were reduced to the corresponding amines which were converted into amides having a sulfonyl or chloroacetyl group in the aryl substituent.     

The assignment of the 1H-NMR and 13C-NMR spectra of 5H-dibenz[b,f]azepine and 10,11-dihydro-5H-dibenz[b,f]azepine

The total assignments of the ¹H-nmr and ¹³C-nmr spectra of 5H-dibenz[b,f]azepine [1] and 10,11-dihydro-5H-dibenz[b,f]azepine ( 2 ) have been made based on comparison with the corresponding 4,6-dideuterated derivatives 3 , and 4 . These compounds were prepared via repeated lithiations and subsequent deuterations of 1 and 2 .     

Napthyridines. IV. Synthesis of benzo[f]-1,7-naphthyridines

Benzo[f]-1,7-naphthyridines have been synthesized from 3-nitrolepidine ( 3 ) by a sequence involving monobromination of the methyl group of 3 , oxidation of the bromomethyl group to the carboxyladehyde group by Franzen's trimethylamine N-oxide procedure, and conversion of the resultant 3-nitro-1-quinoline-carboxaldehyde ( 6 ) to the benzo[f]-1,7-naphthyridine by the Borsche modification of the Friedlander cyclization.     

Nickel-catalyzed regioselective access to dibenzo[c,f]oxocine framework via reductive Heck reaction

Nickel-catalyzed regioselective construction of dibenzo[c,f]oxocine framework with tri-substituted exo-cyclic alkenes have been obtained through an efficient implementation of reductive-Heck protocol. This cost effective, efficient methodology has been demonstrated for the synthesis of various dibenzo[c,f]oxocine derivatives with moderate to good yields.     

Arene imine derivatives of nitrogen heterocycles: 1a,9b-dihydrobenz[h]-azirino[f]quinoline, 1a,9b-dihydrobenz[f]azirino[h]quinoline and 1a,9b-dihydroazirino[f][1,10]phenanthroline

The syntheses of the K-imine derivatives of benzo[h]quinoline ( 1 ), benzo[f]quinoline ( 2 ) and 1,10-phenanthroline ( 3 ) are described. The parent nitrogen heterocycles were oxidized with sodium hypochlorite to the corresponding K-oxides, 4, 6 and 8 , which in turn were reacted with sodium azide. The resulting azido alcohols were then cyclized with triethyl phosphite to the title compounds 5, 7 and 9 . The oxirane ring cleavage in benzo[h]quinoline 5,6-oxide ( 4 ) and in benzo[f]quinoline 5,6-oxide ( 6 ) by sodium azide proceeded by the predicted regioselectivity: 4 gave trans-5-azido-5,6-dihydro-6-benzo[h]quinolinol ( 11 ) and trans-6-azido-5,6-dihydro-5-benzo[h]quinolinol ( 10 ) as the major and minor products respectively, and 6 yielded solely trans-6-azido-5,6-dihydro-5-benzo[f]quinolinol ( 12 ). The latter compound proved by X-ray analysis to crystallize as a hydrogen bonded dimer.     

Benzo[f]-3-aza- and -10-azafluoroanthenes

Reduction of 3-methyl-9-(o-tolyl)-2-azafluoren-9-ol (I) with tin in hydrochloric acid gave 3-methyl-9-(o-tolyl)-2-azafluorene, dehydrocyclization of which on a K-16 catalyst at 520–500°C gave a complex mixture, from which four substances — 2-methylbenzo[f]-3-azafluoranthene, 11-methylbenzo[f]-10-azafluoranthene, benzo[f]-3-azafluoroanthene (II), and I-were isolated and identified by means of the IR, UV, and PMR, and mass spectra. It is shown that the dehydrocyclization proceeds through the hydrogen atoms of the methyl group of the tolyl substituent and takes place at the 8-C or 1-C atom of the azafluorene system. The formation of products II and I constitutes evidence that the reaction is accompanied by partial demethylation or oxidation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1245–1247, September, 1977.     

New dehydration in the pyrrolo[1,2–6-b]isoquinoline series. Preparation and structural identification of 3,5-dihydrobenz[f]indolizin-3-one

3,5-Dihydrobenz[f]indolizin-3-one was prepared by a novel dehydration reaction involving the heating of 1,2,3,5,10,10a-hexahydro[f]indolizine-3,10-dione with polyphosphoric acid. The structure of this new compound was established by X-ray crystallography, by nmr spectroscopy and by reduction to the known products 1,2,3,5-tetrahydrobenz[f]indolizin-3-one and 1,2,3,5,10,10a-hexahydrobenz[f]indolizin-3-one.     

Spectral studies of some substituted arylthiobenzo[f]quinolines

Synthesis and spectral studies (ir, ¹H nmr, ms) of 1- and 3-substituted arylthiobenzo[f]quinolines (IIIa-IIIc, IVa-IVc) obtained through nucleophilic displacement of the corresponding halobenzo[f]quinoline by various thiols (a-c) were done.     

Synthesis of Carbo- and Heterocyclic Cycloprop[f]indenes via cycloaddition of dienes to cyclopropenes

The heterocyclic cycloprop[f]indene 19 was synthesized via cycloaddition of diene 10 to the cyclopropene 11a and subsequent base-induced aromatization. While 19 is isolable, although very short-lived, the oxa analogue 18 decomposed under the conditions required for its preparation. The difluoro derivatives 14 and 15 , in which the heterocyclic moiety is saturated, are accessible by the cycloaddition approach, but the corresponding dichlorides are again not isolable. Cycloprop[f]indenes carrying substituents at C(4) have been obtained via cycloaddition of 22b to 1-bromo-2-chlorocyclopropene. The key step of the sequence is a double Curtius degradation of the cycloadduct 23b to the ketone 27a . While aromatization of the alcohol 27b provided the cycloprop[f]indenol 28b , the reaction failed with 27a . Attempts to convert 28b to 1,3-dihydrocycloprop[f]indene ( 25 ) via the methanesulfonate 28d failed.     

The first examples of the 11H-[2]benzazepino[1,2-a]dibenz[b,f]azocine ring system

The ring closure of 2-[(11,12-dihydro-6-oxodibenz[b,f]azocin-5-yl)methyl]benzoic acid in polyphosphoric acid to 16,17-dihydro-11H-[2]benzazepino[1,2-a] dibenz[b,f]azocine-4-(9H)-11-dione is reported. Degradation studies supporting this structural assignment for the annelation product are described.     

Synthesis of substituted dihydrobenzo[f]pyrimido[4,5-b]-quinolines as tetracyclic 5-deaza nonclassical folates

Cyclocondensation of 2,4,6-triaminopyrimidine ( 10 ) with chlorovinyl aldehyde 7 afforded the linear regioisomer 9,1 1-diamino-5,6-dihydrobenzo[f]pyrimido[4,5-c]quinoline ( 1 ) while the cyclocondensation of 2,6-diamino-4-hydroxypyrimidine ( 11 ) or 6-amino-2,4-dihydroxypyrimidine ( 12 ) with chlorovinyl aldehyde 7 was regiospecific affording the linear regioisomers 9-amino-11-oxo-5,6-dihydrobenzo[f]pyrimido[4,5-c]quinoline ( 2 ) and 9,11-dioxo-5,6-dihydrobenzo[f]pyrimido[4,5-c]quinoline ( 3 ) respectively. The linear structures of these compounds were established by ¹H nmr and ¹³C nmr spectral data.     

Dibenzo[d,f][1,3] dioxepine derivatives: A review

This review presents a survey of synthetic methods and reaction mechanism of the dibenzo[d,f][1,3] dioxepine derivatives. Furthermore, the influence of the substituent groups in 6,6′‐position of dibenzo[d,f][1,3] dioxepine on their conformation is explored. The functional dibenzo[d,f][1,3] dioxepine synthetically versatiles substrate, as they can be used for synthesis of a large variety of π‐conjugated oligomer and polymer containing heterocyclic compounds, such as dibromination dibenzo[d,f][1,3] dioxepine derivative as a raw material of synthesis for organic semiconductor polymers. The synthetic and fluorescent property of π‐conjugated polymers basic on dibenzo[d,f][1,3] dioxepine also is explored. J. Heterocyclic Chem., (2012).     

Electrophilic substitution of dibenz[b,f]oxepin

Dibenz[b,f]oxepin undergoes nitration and acid-catalyzed deuteration at the 10-position and adds bromine across the 10,11 bond. These reactions contradict predictions made by the SCFMO method. Chemical reactions and NMR spectroscopy suggest that dibenz[b,f]oxepin is only weakly aromatic.     

Facile synthesis of 3‐substituted [1,2,4]triazino[3,4‐f]purine‐4,6,8‐trione derivatives

A new synthetic route to build the [1,2,4]triazino[3,4‐ f]purine nucleus is described. The novel [1,2,4]‐triazino[3,4‐ f]purine‐4,6,8(l H,7 H,9 H)‐trione derivatives were obtained by condensation of 8‐hydrazinotheophylline with appropriate glyoxylic acids via the intermediate hydrazones.     

Electron transfer from dibenzo[b,f]-1-azapentalene dianion: Attempted synthesis of dibenzo[b,f]-1-azapentalene

When dibenzo[b,f]-1-azapentalene dianion (3) was allowed to react with either iron (III) chloride or ethylene bromide, a one-electron transfer from3 took place readily to give the radical anion11. Further electron transfer from11 did not occur presumably due to the antiaromatic character of dibenzo[b,f]-1-azapentalene (1) that would have resulted. The radical anion11 underwent further transformation by hydrogen abstraction from the solvent to give 5,10-dihydroindeno[1,2-b]indole (2) and by dimerization to themeso and (R,S) isomers of 5,5,10,10-tetrahydro-10,10-biindeno[1,2-b]indole (4 a and4 b) respectively.

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Elektronentransfer von Dibenzo[b,f]-1-azapentalen-Dianion: Ein Versuch zur Synthese von Dibenzo[b,f]-1-azapentalen

Zusammenfassung Die Reaktion von Dibenzo[b,f]-1-azapentalen-Dianion (3) mit Eisen (III) oder Ethylenbromid ergab einen Ein-Elektronentransfer zum Radikalanion11. Ein weiterer Elektronentransfer fand nicht statt, vermutlich wegen des antiaromatischen Charakters von Dibenzo[b,f]-1-azapentalen (1), das dabei entstehen müßte. Das Radikalanion11 ergab unter Wasserstoffentzug aus dem Lösungsmittel 5,10-Dihydroindeno[1,2-b]indol (2), das weiter zummeso- bzw. (R,S)-5,5,10,10-tetrahydro-10,10-biindeno[1,2-b]indol (4 a bzw.4 b) dimerisierte.

     

Preparation of 8H-Furo[3,4-d]dibenz[b,f]azepine. A Novel Heterocyclic Ring system

The synthesis of 8H-furo[3,4-d]dibenz[b,f]azepine 8 from 5H-dibenz[b,f]azepine 1a is described. The preparation of 8 represents the synthesis of a new heterocyclic system.     

SYNTHESIS,REACTIVITY AND CONFORMATION OF 10,11-DIHYDRODIBENZO-[b,f]PHOSPHEPIN AND DIBENZO[b,f]PHOSPHEPIN DERIVATIVES. PHOSPHORUS ANALOGUES OF IMINOBIBENZYL ANTIDEPRESSANTS

Abstract

Derivatives of the novel dibenzo[b,f]phosphepin system are prepared from 10,11-dihydro-5-phenyl-5H-bibenzo[b,f]phosphepin 5-oxide (2). New members in the 10,11-dihydro-5H-dibenzo[b,f]phosphepin series, including phosphorus analogues (7, 10) of the andidepressant drug imipramine (30), are also reported. Products of nucleophilic substitution at tetrahedral phosphorus in 2 appear to be determined by the relative apicophilicity of the nucleophile. Conformational analysis based on ¹H NMR data suggests folded (“butterfly”) conformation for the tricyclic compounds. The twisted boat conformation of the central ring in the 10,11-dihydro compounds bears a pseudo-equatorial P[dbnd]O oxygen or a P[dbnd]S sulfur, in solution. Symmetric AA‘BB’ spin systems are found in 4,5 and 7, and their solution conformations appear to be similar to those of analogous 10,11-dihydrodibenzo[b,f]azepine derivatives. The interaction of some compounds with NMR shift reagents and their mass spectral fragmentations are discussed.