Novel stereoselective synthesis of 2,3-dihydro-1H-benzo[f]chromen-3-amine derivatives through a one-pot three-component reaction

A short and stereoselective novel synthesis of benzo[f]chromen-3-amine derivatives in good yields, through a three-component aromatic Betti type reaction under solvent free conditions is reported. The spontaneous reaction occurs in the absence of acid catalysts. The use of chiral 1-phenylethylamine or α,β-unsaturated aldehydes allowed us to prepare enantiopure benzo[f]chromen-3-amine derivatives with good stereoselectivity. Conformational analysis compared with the ¹H NMR data of the products obtained, allowed us to the determine the absolute configuration, which was also confirmed by X-ray analysis.     

First example of multicomponent synthesis of 1-ethoxy-3-(4-aryl)-1-phenyl-1H-benzo[f]chromene derivatives

A new series of 1-ethoxy-3-(4-aryl)-1-phenyl-1H-benzo[f]chromenes have been synthesized efficiently.The procedure involves the multicomponent reaction of 2-naphthol,acetophenone derivatives,and triethyl orthobenzoate catalyzing by efficient bis(2-anilinotropone) Ti complex.     

Microwave-assisted synthesis and antibacterial activity of derivatives of 3-[1-(4-fluorobenzyl)-1H-indol-3-yl]-5-(4-fluorobenzylthio)-4H-1,2,4-triazol-4-amine

Herein, an excellent method for the synthesis of twelve novel Schiff base derivatives containing indole and triazole assisted by microwave irradiation is reported. Compared with the conventional method, the yields increased from 59–84 % to 85–96 % and the reaction time was reduced from 24–30 h to 4–8 min. Moreover, all series of the newly synthesized Schiff bases were evaluated for their antibacterial activity. The values of minimum inhibitory concentration (MIC) and IC50 indicated that many target compounds possessed excellent antibacterial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis.     

A new short synthesis of 3-substituted 5-amino-1-(chloromethyl)-1,2-dihydro-3H-benzo[e]indoles (amino-CBIs)

A new short synthesis of 3-substituted 5-amino-1-(chloromethyl)-1,2-dihydro-3H-benzo[e]indoles from Martius Yellow is disclosed. The key steps of the synthesis were three efficient regioselective reactions (iodination, 5-exo-trig aryl radical-alkene cyclization and carboxylation).     

Synthesis of novel chiral fluorinating agents, （＋）- and （-）-N-fluoro-3-methyl-3-（4-methylphenyl）-2H-benzo[e] [ 1,2]thiazine- 1,1,4-triones

Treatment of N-t-butylbenzenesulfonamide with an excess of BuLi, followed by the reaction with methyl 2-（4-methylphenyl）propanoate, gave the corresponding 2-carboxybenzenesulfonamide, which underwent a sequence of consecutive N-deprotective cyclization process mediated by TMSCI-NaI-MeCN reagent to afford the N-sulfonylimine. Following the bromination and ring expansion, 3-methyl-3-（4-methylphenyl）-2H-benzo[e][1,2]thiazine-l,l,4-trione was obtained. Optical resolution of the racemic benzosultam using （-）-menthoxyacetyl chloride, furnished the optically p.ure （＋）- and （-）-3-methyl-3-（4-methylphenyl）-2H- benzo[e][1,2]thiazine-1,1,4-triones, which were fluorinated with FC103 to produce the corresponding chiral N-F agents.     

Derivatives of benzo[4,5]cyclohepta[1,2-b]thiophene. 4. Synthesis of 1-(9,10-dihydro-4H-benzo[4,5]cyclohepta[1,2-b]thiophen-4-yl)-3-alkylaminoazetidines

Thirteen 1-(9,10-dihydro-4H-benzo[4,5]cyclohepta[1,2-b]thiophen-4-yl)-3-alkylaminoazetidines 11 have been synthesized in three steps from 4-amino-9,10-dihydro-4H-benzo[4,5]cyclohepta[1,2-b]thiophene ( 6 ), which was obtained from the reduction of either 4-azido 4 or 4-hydroxyimino 5 derivatives. All the compounds have been evaluated as potential antidepressive agents.     

One-step synthesis of substituted 2-amino-5,6,7,8-tetrahydro-4H-benzo[b]pyrans. Molecular and crystal structure of 2-amino-3-(2-methoxyethoxycarbonyl)-4-(2-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran

Substituted 2-aminobenzo[b]pyrans were synthesized by three-component condensation of aromatic aldehydes, cyanoacetic acid derivatives, and cyclic 1,3-diketones. The molecular and crystal structure of 2-amino-3-(2-methoxyethoxycarbonyl)-4-(2-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran was established by X-ray diffraction analysis.     

New synthesis of 3-amino-1H-benzo[f]chromene-2-carbonitriles

3-Amino-1H-benzo[f]chromene-2-carbonitriles were synthesized by non-catalytic reaction from Mannich bases of the naphthalene series and malononitrile. Reactive 1-benzylidene(or methylidene)naphthalen-2(1H)-ones were presumed as intermediate products.     

1-Ethyl- and 1,2-dimethyl-3-(p-methoxyphenyl)benzo[f]quinolines and their transformations

Condensation of p-methoxybenzylidene-2-naphthylamine with methyl ethyl ketone leads to a mixture of 1-ethyl- and 1,2-dimethyl-3-(p-methoxyphenyl)benzo[f]quinolines, for which protic and quaternary salts were obtained. Cyanine dyes were synthesized from 1,2-dimethyl-3-(p-methoxyphenyl)benzo[f]quinoline methiodide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1223–1226, September, 1976.     

One-pot,three-component synthesis and in vitro antibacterial evaluation of novel 3-amino-N-benzyl-1-aryl-1H-benzo[f]chromene-2-carboxamide derivatives

A series of novel 3-amino-N-benzyl-1-aryl-1H-benzo[f]chromene-2-carboxamides have been synthesized by the reaction of N-benzyl-2-cyanoacetamide with 2-naphthol and aromatic aldehydes in the presence of piperidine as a base. The chemical structures of all the compounds were confirmed by spectroscopic methods as well as elemental analysis. In addition, the antibacterial activities of some target compounds against Gram-negative and Gram-positive bacteria in vitro were determined. Among these compounds, 4b, 4c, 4h and 4i exhibited antibacterial effects. The advantages of the present work reaction are clean reaction, metal-free transition, environmentally friendly approach to prepare different benzo[f]chromene-2-carboxamide derivatives, good yields, low cost, readily available starting materials and in addition does not need cumbersome procedure.     

Reaction of 4-nitro-1,2-phenylenedl4mine with 1-(4-R-phenyl)-3-(4-nitrophenyl)propenones

By the reaction of 4-nitro-1,2 phenylenediamine with 1-(p-R-phenyl)-3-(4-nitrophenyl)propenones, Michael adducts with a 1:2 composition have been obtained. A stagewise scheme is proposed for the formation of these compounds. The structure of one of the products has been established by means of x-ray structure analysis.Deceased     

Photochromic dihetarylethenes. 10. Photochromic 1,2-bis[2-(benzothiazol-2-yl)-3-thienyl]- and 1,2-bis[2-(benzothiazol-2-yl)benzothiophen-3-yl]ethenes

Dithienylethenes containing the thiophene rings with benzothiazolyl substituents in position 2 were synthesized. 1,2-Bis[2-(benzothiazol-2-yl)benzothiophen-3-yl]hexafluorocyclopentene and 1,2-bis[2,5-di(benzothiazol-2-yl)-3-thienyl]hexafluorocyclopentene possess photochromic properties. The open forms of 1,2-bis(2-benzothiazolylhetaryl)ethenes fluoresce, but introduction of the benzothiazole rings into dihetarylethenes significantly lowers the fatigue resistance of photochromes and favors thermal reversibility.     

Parallel Solid-Phase Synthesis of disubstituted 3-(1H-benzo[d]imidazol-2-yl)imidazolidine-2,4-diones and 3-(1H-benzo[d]imidazol-2-yl)-2-thioxoimidazolidin-4-ones

A multistep approach to construct novel 3-(1H-benzo[d]imidazol-2-yl)imidazolidine-2,4-diones and 3-(1H-benzo[d]imidazol-2-yl)-2-thioxoimidazolidin-4-ones from commercially available amino acids, amines, and carboxylic acids is described. Coupling of Fmoc-amino acid to resin-bound aminobenzimidazole provided following Fmoc elimination free amine. Treatment of the free amine with 1,1′-carbonyldiimidazole or 1,1′-thiocarbonyldiimidazole furnished the corresponding hydantoins and thiohydantoins via intramolecular cyclization. The desired aminobenzimidazole tethered hydantoins or thiohydantoins were isolated in good yields.     

X-ray Diffraction Investigation of Ethyl 2-（2-Amino-3-ethoxycarbonyl-4H-benzo[f]chromene-4-yl） Cyanoacetate

The title compound,ethyl 2-(2-amino-3-ethoxycarbonyl-4H-benzo[f]chromene-4-yl) cyanoacetate 4,has been synthesized and its crystal structure was characterized by X-ray single-crystal diffraction.The crystal belongs to monoclinic,space group P21/n with a=12.9408(18),b=11.1870(13),c=13.8975(19),β=109.261(2)°,Z=4,C21H20N2O5,Mr=380.39,V=1899.3(4)3,Dc=1.330 g/cm3,μ=0.096 mm-1,F(000)=800,S=1.027,R=0.0535 and wR=0.1012 for 1365 observed reflections(I 2σ(I)).X-ray analysis reveals N-H…π interactions,π…π interactions and hydrogen bonds in the title molecule.     

Oxa-[3+3] annulation of 1H-benzo[f]chromene-2-carbaldehydes and 2-naphthols: synthesis of 7aH,15H-benzo[f]benzo[5,6]chromeno[2,3-b]chromenes

Chemistry of Heterocyclic Compounds - A method for the preparation of polycondensed chromeno[2,3-b]chromenes was developed based on the formal [3+3] cycloaddition reaction between...     

NMR study on cis-N-[4-[4-(1,2-benzisozole-3-yl)-1-piperazinyl] butyl]cyclohexane-1,2-dicarboximide monohydrochloride dihydrate

Cis-N-[4-[4-(1,2-benzisozole-3-yl)-1-piperazinyl]butyl]cyclohexane-1,2-dicarboximide monohydrochloride dihydrate was studied spectroscopically. Complete NMR assignments were made using DEPT, H-H COSY, as well as HMQC and HMBC heteronuclear correlation techniques. The hydrochloride salt was found at delta > 10. The dihydrate was present in the region delta 3-4 in DMSO-d6 solvent. Asymmetry carbon C3 brought chemical-shift-nonequivalent of cis-cyclohexanyl group, splitting four systems H1, H1', H2 and H2'. Diamagnetic anisotropy of benzisozolyl group results in three troops peaks of piperazinyl group.     

电化学合成1, 4-双[2-(3, 4, 5-三甲氧基苯基)乙烯基]苯

1,4-双[2-(3,4,5-三甲氧基苯基]苯[简称HPV]采用有机电化学的方法合成,对合成的原理和方法进行研究和探讨,得到此化合物的三种异构体的淡黄色混合物,即含29.4%全顺式,44.7%顺-反式和25.9%全顺式。所得混合物熔点范围为103-155℃,总得率为92%。     

Synthesis and study of new 2-aryl-1-(4-nitrophenyl)-1,1a-dihydroazireno[1,2-a]quinoxaline derivatives

New derivatives of photochromic 2-aryl-1-(4-nitrophenyl)-1,1a-dihydroazireno[1,2-a]quinoxalines were synthesized by condensation of 4-methyl-and 4,5-dimethyl-1,2-phenylenediamine with 1,3-diaryl-2,3-dibromopropan-1-ones. The reactions of 4-methyl-1,2-phenylenediamine produce mixtures of regioisomers. The chemical properties of the reaction products were studied. The structure of one of the latter was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 350–356, February, 2006.     

Stereoselektive Synthesen von (Z)-(10-Methoxy-4H-benzo[4,5]cyclohepta[1,2-b]thiophen-4-yliden)essigsäure

Stereoselective Syntheses of (Z)-(10-Methoxy-4H-benzo[4,5]cyclohepta[1,2-b]thiophen-4-ylidene)acetic Acid Two stereoselective syntheses for the antiinflammatory compound 1 ((Z)-isomer) are described. In the first approach (Strategy A, Scheme 1) the stereoselective synthesis of 1 was realized via the bicyclic compound 11 under thermodynamic conditions, followed by a thiophene annelation with retention of the double-bond geometry (Schemes 2–4). Optimized conditions were necessary to avoid (E/Z)-isomerization during annelation. In the second approach (Strategy B, Scheme 1), diastereoisomer 17b was obtained selectively from a mixture of the diastereoisomers 17b and 18b by combining thermodynamic epimerization and solubility differences (Scheme 5). Diastereoisomer 17b was converted into the tricyclic compound 23 using a novel thiophene annelation method which we described recently (Scheme 6). In a final step, a stereospecific ‘syn’-elimination transformed the sulfoxide 24 into the target compound 1 (Scheme 7). To avoid (E/Z)-isomerization, it was necessary to trap the sulfenic acid liberated during the reaction. The key reactions of both approaches are highly stereoselective (> 97:3).