Condensation of 4-phenyl-3,5-dicarboethoxycyclopentane-1,2-dione with primary amines

Condensation of the title compound ( 1 ) with primary aromatic amines gave the dianilides ( 2 ), which cyclized to cyclopenta[1,2-c:4,3-c′]diquinolines ( 3 ). Treatment of 1 with o-phenylenediamine or 2,3-diaminopyridine afforded cyclopenta[2,1-b:3,4- b ′]bis[1,5]benzodiazepine ( 4 ) and bis[1,5]pyrido[b]diazepine derivative ( 5 ), respectively. Whereas, with o-aminophenol a mixture of 2c and cyclopenta[2,1- b :3,4- b ′]bis[1,5]benzoxazepine ( 7 ) was obtained. Pechmann reaction of 1 with m-cresol gave the bis[1]benzopyrane ( 9 ). Mannich reaction of 1 with benzylamine afforded the 3-azabicyclo[3.2.1]octane system ( 10 ).     

Die Nitril-Carboxamid-Umlagerung

The Nitrile Carboxamide Rearrangement By reaction of cyclohexanone-2-carboxamide ( 4 ) with cyan amide 1-cyano-cyclohex-1-en-2-yl-urea ( 6 ) is formed via nitrile carboxamide rearrangement. Whilst compound 6 with 1,2-diaminobenzene hydrochloride forms 11-amino-1 H-2,3,4,5-tetrahydrodibenzo[b,e][1,4]diazepin hydrochloride ( 8 and 8a ), compound 6 and 1,2-diaminobenzene form hexahydro-benzimidazo[1,2-c]-quinazolin-6-one ( 12 ). Compound 8 with sodium hydroxide yields 11-amino-1 H-2,3,4,11a-tetrahydrodibenzo[b,e]-[1,4]diazepin ( 9 ). Compound 6 reacts with cyclohexylamine to form N-(1-cyanocyclohex-1-en-2-yl)-N′-cyclohexyl urea ( 10 ). Compound 10 with 1,4- or 1,2-diaminobenzene hydrochloride yields compound 7 and 8 . In alkaline solution 10 cyclises to 4-amino-3-cyclohexyl-2,3,5,6,7,8-hexahydroquinazolin-2-one ( 11 ). Compound 4 and malonitrile form either 3-amino-4-cyano-1,2,5,6,7,8-hexahydro-isoquinol-1-one ( 13 ) or 1-amino-4-cyano-2,3,5,6,7,8-hexahydro-isoquinol-3-one ( 14 ). Compound 13 and alkaline formaldehyde react to cyanooctahydroisoquinoline-[2,3-c] [1,3,5]oxdiazin-6-one ( 17 ). 2-Cyanoethyl-cyclohexan-one-2-carboxamide ( 22 ), prepared by Michael-reaction from 4 and acrylonitrile, forms via nitrile carboxamide rearrangement 10-cyano-1,2,3,4,5,6,7,10-octahydroquinolin-2-one ( 24 ) and 2-(1′-cyano-cyclohexyl-2′-one)-propionic acid ( 25 ). Nucleophilic attack of the NH₂-group at the cyanogroup of compound 22 forms 5-(spirocyclohexan-2′-one)-hexahydropyridin-2,6-dione ( 27 ).     

Reactions with β-ketodianilides. I. New synthesis of Pyrido[3,4-c]pyridine Derivatives

Acetonedicarboxylic acid dianiline reacted with malononitrile, ethyl cyanoacetate or benzoylacetonitrile to give (6-amino-5-cyano-1,2-dihydro-2-oxo-1-phenylpyrid-4-yl)-acetanilide ( 3 ), (3-cyano-2,6-dioxo-1-phenyl-1,2,5,6-tetrahydropyrid-4-yl)acetanilide ( 8 ) or (3-cyano-1,6-dihydro-1,2-diphenyl-6-oxopyrid-4-yl)acetanilide ( 9 ). Compounds 3 and 8 could be cyclised into 8-amino-1,6-diphenyl-1,2,4,5,6,7-hexahydro-7-iminopyrido[3,4-c]pyridine-2,5-dione ( 4 ) and 7-amino-1,2,3,5,6,8-hexahydro-1,6-diphenylpyrido[3,4-c]pyridine-2,5,8-trione ( 10 ) respectively by heating their solutions in dimethylformamide in the presence of triethylamine. Each of 3 and 4 coupled with arenediazonium chlorides to give the corresponding arylhydrazone derivatives ( 5a–d ) and ( 6a–c ), respectively. Condensation of 4 with p-nitrosodimethylaniline yielded 8-amino-4- (p-dimethylaminophenylimino)-1,6-diphenyl-1,2,4,5,6,7-hexahydro-7-iminopyrido[3,4-c]pyridine2,5-dione ( 7 ).     

Synthesis of pyrazolo[4′,3′:5,6]pyrazino[2,3-c]pyrazoles and pyrazolo[4′,3′:5,6]pyrazino[2,3-d]pyrimidines and their application to polyester fibres

4-Nitroso-1-phenyl-3-methyl-5-aminopyrazole ( 1 ) was condensed with ethylcyanoacetate ( 2 ), malononitrile ( 4a ) and 2-cyanomethylbenzimidazole ( 4b ) to yield 6-hydroxy-5-cyano, 6-amino-5-cyano and 6-amino-5-(benzimidazol-2-yl)-3-methylpyrazolo [3,4-b]pyrazines 3, 5a and 5b , respectively. 5-Cyano-6-chloro derivative 6 obtained from 3 was converted to 3-aminopyrazolo[4′,3′:5,6]pyrazino[2,3-c]pyrazoles 8a and 8b by the treatment with hydrazin hydrate ( 7a ) and phenylhydrazine ( 7b ), respectively. Compound 5a was treated with formamide ( 9a ), urea ( 9b ) and thiourea ( 9c ) to give 4-aminopyrazolo[4′,3′:5,6]pyrazino[2′3′-d]pyrimidines 10a–10c. With refluxing acetic anhydride compounds 8a, 8b and 10a gave corresponding acetamido derivatives 8c, 8d and 10d. Compound 5a was treated with ethylorthoformate ( 11 ), acetic anhydride ( 12 ) or benzoylchloride ( 13 ) to give fused benzimidazopyrazolo[4′,3′:5,6]pyrazino[2′,3′-d]pyrimidines, viz., benzimidazol[1,2-c]pyrazolo[4,3-g]pteridines ( 14a–14c ). Some of the compounds 8, 10 and 14 were applied to polyester as disperse dyes and their fastness properties were studied.     

Studies on alkylheterocycles. I. A convenient Synthesis of Phthalazines

Ethyl-2-arylhydrazono-2,3-dioxobutyrate 1a, b reacted with ethylcyanoacetate to yield the pyridazino derivatives 2a, b . Similarly, the pyridazine 2c was obtained via reaction of 3-arylhydrazonopentan-2,3,4-trione with the same reagent. The phthalazines 6 were obtained upon reaction of 2a–c with ylidenemalonitrile 3a, b . The styrene derivatives 7a–d were isolated from the reaction of 2a–c with the appropriate aromatic aldehyde. Compounds 7a–d were subsequently utilized for the synthesis of 6a, d–f respectively via reaction with malononitrile. On the other hand, the phthalazine derivative 8 was formed upon reaction of 2a with either ethylcyanoacetate or malononitrile.     

Synthesis and antimicrobial activity of certain novel monomethine cyanine dyes

A series of novel monomethine cyanine dyes were synthesized by using 3-methyl-5-substituted-1-phenyl-pyrano[2,3-c]pyrazole derivatives 2a–c. Reaction of equimolar ratios of 2a–c with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 3a–c. Reaction of compound 5 with 2(4)-methyl heterocyclic quaternary salts gives monomethine 6a–c. Condensation reaction of equimolar ratios of compounds 7 and 9a,b with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 8a–c and 10a,b respectively. The new synthesized monomethine cyanine dyes were identified by elemental analyses, IR, ¹H-NMR and Ms spectral data. The electronic absorption spectra in ethanolic solution of novel monomethine cyanine dyes were measured and the antimicrobial activity of some selected monomethine cyanine dyes was discussed.     

Zur Chemie der 3-Aroylimino-3H-1,2-dithiole

Reactions of 3-Aroylimino-3H-1,2-dithioles The thiolates 3 and 10 prepared from 3-aroylimino-4-aroylthio-5-cyano-3H-1,2-dithioles 1 with bases, react with alkylhalides and acylhalides to the corresponding 4-S-substituted compounds 6, 11 and 7 , respectively. Treatment of the thiolates with 1-chloropropanone gives the bicyclic compound 12 by intramolecular cyclization involving the 5-cyano-group. 3,6-Bis-(acylimino)-3H,6H-[4,3-c] [1,2]-dithioles 2 or 8 are prepared from the S-acylated dithioles 1 or 7 and sulphur in pyridine/benzene. 1,2,4-Triazines 13 are formed by the reaction of dithiol es 1 orthiolates 3 with phenylhydrazine. The thiolates give upon protonation the mesoionic dithioliumthiolates 4 . Coordination compounds are obtained from the reaction of the thiolates with cations of 3d-elements. On the basis of the chemical behaviour of the new 3-acylimino-1,2-dithioles and the results of spectroscopic measurements a strong bonding interaction between the N-acyl-carbonylgroup and the dithiole ring system in these compounds is supposed.     

The Use of an Unusual Rearrangement Sequence for the Syntheses of 3‐(1‐Aminoalkylidene)‐3H‐thiophen‐2‐ones and two Examples of their Surprising Electrophilic‐Induced Dimerization Reactions

The reaction of 2‐amino‐3‐carbomethoxythiophene ( 1a ) and 2‐amino‐3‐carboethoxy‐4,5‐dimethylthiophene ( 1b ) with methyl‐ or ethylmagnesium chloride leads to new 3‐(1‐aminoalkylidene)‐3H‐thiophen‐2‐ones 4a—d in good yields (60—87%). Treatment of the compounds 4a and 4c with catalytic amounts of p‐TsOH in boiling CHCl₃ afforded the (±)‐4,4′‐bis‐(1‐aminoalkylidene)‐3′,4′‐4H,2′H‐[2,3′]bithiophenyl‐5,5′‐diones 9a and 9b as new interesting heterocycles in preparatively useful yields (60/mdash;65%).     

Reaction of 3H, 6H-1, 2-Dithiolo[4,3-c]1,2-dithiole-3, 6-dithione with primary aliphatic amines

The reaction of 3H,6H-1,2-dithiolo[4,3-c]1,2-dithiole-3, 6-dithione ( 1 ) with primary aliphatic amines ( 8a , b ) gives 3H,6H-3,6-bisalkylimino-1,2-dithiolo[4,3-c]1,2- dithiole ( 9a , b ), 3H,3-N-alkylamino-5-N-alkylthiocarbamido-1, 2-dithiolium-4-thiolate ( 10a , b ) and 3H,3-N-alkylimino-4-alkylamino-5-N-alkylthiocarbamido-1,2-dithiole ( 11a , b ). The compounds 9-11 can be formed from one another. The compounds 10a , b react with nickel chloride to the stable complexes 14a , b . In basic medium 10 gives the salt of 3H,3N-alkylthiocarbamido-1,2-dithiole-4-thiolate 15 , which reacts with methyl iodide to 3H,3N-alkylimino-5-N-alkylthiocarbamido-4-methylthio-1,2-dithiole 16 .     

Reaction of ethyl N-(6-ethoxycarbonyl-2-methylthiothieno[2,3-d]-pyrimidin-5-yl) formimidate with alkyl- and arylhydrazines: Formation of modified thieno[2,3-d]pyrimidines and thieno[2,3-d:4,5-d]dipyrimidin-4-ones

The reaction of ethyl N-(6-ethoxycarbonyl-2-methyl-thiothieno[2,3-d]pyrimidin-5-yl)formimidate ( 1 ) with methyl-hydrazine, N,N′-dimethyl- and N,N′-diphenylhydrazines separately in refluxing ethanol resulted in hydrolysis of formimidate group to give ethyl 5-amino-2-methylthiothieno[2,3-d] pyrimidine-6-carboxylate ( 2 ). The reaction on 1 with methyl-hydrazine without solvent afforded ethyl 5-amino-2-(1-methyl-hydrazino)thieno[2,3-d]pyrimidine-6-carboxylate ( 3 ), which underwent hydrazone formation with p-nitrobenzaldehyde to give 4 . Treatment of 1 with N,N-dimethylhydrazine afforded a mixture of 3-dimethylamino-7-methylthiothieno[2,3-d:4,5-d']dipyrimidin-4(3H)-one ( 5 ) and 2 . Displacement of methylthio group in 5 with morpholine, piperidine and 4-methylpiperazine gave the corresponding 7-substituted derivatives 6a-c . The reaction of 1 with para-substituted phenylhydrazines resulted in the formation of 3-(p-substituted phenylamino)7-methylthiothieno[2,3-d:4,5-d']dipyrimidin-4 (3H)ones ( 7a-c ).     

Synthesis of Some Benzoquinolines and Benzacridines

2-Arylidene-3,4-dihydro-1(2H)-naphthalenones 1 react with ethyl cyanoacetate in presence of ammonium acetate to give 4-aryl-7:8-benzo-3-cyano-1,2,3,4,5,6-hexahydro-2-oxoquinoline 2 , 4-aryl-7:8-benzo-3-cyano-2-oxo-1,2,5,6-tetrahydroquinoline 3 and an oily product 4 . Hydrolysis and decarboxylation of 4 gave β-aryl-β-(2-α-tetralonyl)propanoic acid 5 . Thermolysis of 4 gave 2 and 3 . Compounds 2 and 3 were also obtained by treatment of 1 with cyanoacetamide using piperidine as a catalyst. Condensation of 1 with diethyl malonate, cyclohexanone, and α-tetralone in presence of ammonium acetate afforded 4-aryl-7:8-benzo-1,2,3,4,5,6-hexahydro-2-oxoquinoline 8 , 9-aryl-3:4-benzo-1,2,6,7,8,10-hexahydroacridine 9 , and 9-aryl-3:4,5:6-dibenzo-1,2,7,8-tetrahydroacridine 10 , respectively.     

Zur Synthese von 3-Amino-naphth[c]isothiazolen

Synthesis of 3-Amino-naphth[c]isothiazoles 3-Amino-naphthonitrile-2 7 can be readily prepared by ring cleavage of 4-carboxy-methylthio-benzo[g]quinazoline 6 in aqueous medium at pH 9. 1-Amino-naphthonitrile- 2 11 is formed in good yield by thermolysis of 1H-benzo[g]-indoline-2,3-dione-3-oxime 13 (BEDFORD -PARTRIDGE reaction). The scope of both reaction types is studied. Appropriate syntheses of each precursor are reported. By base-catalyzed addition of hydrogen sulfide under pressure 7 and 11 were transformed into amino-thionaphthoic-2-acid amides 17 and 23 . Oxidation of 1-amino-thionaphthoic-2-acid amide 23 with hydrogen peroxide in methanol produced 3-aminonaphth[1,2-c]isothiazole 1b in almost quantitative yield. A similar oxidative cyclization of 3-amino-thionaphthoic-2-acid amide 17 to 3-amino-naphth[2,3-c]isothiazole 3b failed even if the reaction conditions were widely varied. The unsuccessful efforts to synthesize „linear”︁ naphthisothiazoles ( 3a and its 3-amino derivative 3b ) are discussed in terms of the superdelocalizability of these heterocycles. Azo dyes can be obtained from 1b and 7 .     

Amino-thieno[2,3–c]pyrazole und Amino-thieno[2,3–b]pyrrole

Amino-thieno[2,3–c]pyrazoles and Amino-thieno[2,3–b]pyrroles The synthesis of thieno[2,3–c]pyrazoles and thieno[2,3–b]pyrroles is described. From the dithioliumsalt ( 1 ) and potassium hydroxide the potassium-(2,2-dicyan-1-methylthio-ethen-1-yl)-thiolate ( 2 ) is formed. This reacts with hydrazine hydrate to form the 3-amino-5-thioxo-pyrazol-4-carbonitrile ( 3 ) S-Alkylation with α-chlorocarbonyl compounds yielding ( 6a–c ) leads via Thorpe-Ziegler-cyclization to 3,4-diamino-thieno[2,3–c]pyrazoles ( 9 ) if the position 1 is alkylated ( 8 ). Acetyl acetone yields 2-mercapto-pyrazolo[1,5–a]pyrimidine ( 5 ). After S-alkylation ( 10a–d ) are immediately cyclized to thieno [2′,3′:3,4]pyrazolo[1,5-a]pyrimidine ( 11a–d ). The ketone ( 6a ) can be cyclized to the pyrazolo [5,1–b]thiazole ( 12 ). 3 reacts with oxalyl chloride to form the 2,3-dioxo-6-thioxo-imidazo[1,2-b]pyrazole ( 13 ) of which S-phenacyl derivative ( 14 ) because the NH-proton cannot be cyclized. The 5-amino-3,4-dicyano-pyrrol-2-thiolate ( 16 ) shows the analogous behaviour. The S-alkylation is followed by cyclization, and 3,5-diamino-thieno[2,3–b]pyrroles ( 18a–b ) arise. Reaction of 5-amino-2-alkylthio-pyrrol-3,5-dicarbonitrile ( 17 ) with acetyl acetone provides pyrrolo[1,2-a]pyrimidine ( 20a–c ) which can be cyclized to form thieno[3′,2′:4,6]pyrimidines ( 21a–c ) very easily.     

Novel olygomeric C-3 esters of betulin derivatives

Novel copolymers of C-3 esters of betulin derivatives (3-hydroxy-1-cyano-2,3-seco-2-nor-19β,28-epoxyoleane 3-O-vinylbenzoate (I), 3-hydroxy-1-cyano-2,3-seco-2-nor-19β,28-epoxyoleane 3-O-vinylacetate (II), methyl 3-hydroxy-1-cyano-2,3-seco-2-norlup-20(29)-en-28-oate 3-O-vinylbenzoate (III)) with N-vinylpyrrolidone and acrylonitrile have been prepared by free radical copolymerization. Kinetic regularities of the process were investigated. New water-soluble silver nanocomposites based on (III) copolymer with N-vinylpyrrolidone [poly((III)-VP)] have been developed. The average silver particle size ranged from 40 to 52?nm, with the corresponding UV–vis absorption peak position at 400?nm. The nanocomposite obtained has a significant cytotoxic activity toward melanoma cell line and may be considered for the development of new materials for medical applications.     

Heterocyclic synthesis with nitriles: Syntheses of some novel pyrazolo[1,5-a]pyrimidine and Pyrrolo[2′,3′:3,4]pyrazolo[1,5-a]pyrimidine Derivatives

3,5-Diamino-4-phenacylpyrazoles 1a , b react with the cinnamonitriles 2a , b to afford the novel 7-phenacylpyrazolo[1,5-a]pyrimidine derivatives 4a – d , respectively. Compounds 4c , d undergo cyclization with trichloroacetonitrile to afford the novel tricyclic system pyrrolo-[2′,3′:3,4]pyrazolo[1,5-a]pyrimidine derivatives 5e , f , respectively.     

The STOBBE condensation. XI. The cyclisation of (Z)- and (E)-3-methoxycarbonyl-2-methyl-4-(2′-naphthyl)-4-phenyl-but-3-enoic acids to the corresponding polysubstituted phenanthrene and naphthalene derivatives

(Z)- and (E)-3-methoxycarbonyl-2-methyl-4-(2′-naphthyl)-4-phenyl-but-3-enoic acids 1 a and 4 a have been converted into methyl-4-acetoxy-3-methyl-1-phenylphenanthrene-2-carboxylate 2 a and methyl 4-acetoxy-3-methyl-1-(2′-naphthyl)-2-naphthoate 5 a . The derived phenolic acids 2 b and 5 b are converted to methyl 4-methoxy-3-methyl-1-phenyl-phenanthrene-2-carboxylate 2 c and methyl 4-methoxy-3-methyl-1-(2′-naphthyl)-2-naphthoate 5 c ; which are saponified to the corresponding methoxy acids 2 d and 5 d . Alcoholysis of the anhydrides 3 and 6 gives the corresponding half-esters 1 c and 4 c , respectively.     

Syntheses of 3-Acyl-4-hydroxy-2(1H)quinolones

3-Acyl-4-hydroxy-2(1H)-quinolones 5 are obtained by hydrolytic ring opening and subsequent decarboxylation from the corresponding pyrano[3,2-c]quinolin-2,5(6H)-diones 4 , which in turn are easily obtained from 1:2 condensation of anilines 1 with diethyl malonate 2a or 1:1 condensation of diethyl alkyl- or arylmalonates 2b–e with 4-hydroxy-2(1H)-quinolones 3 . Nitropyranoquinolinediones 6 furnish after ringopening 3-nitroacetyl-4-hydroxy-2(1H)quinolones 8 . Pyranoquinolines 7 and 9 with acetyl- or aminosubstituents are hydrolyzed during basic ringopening to yield 5 .     

Direct (hetero)arylation polymerization for the synthesis of donor–acceptor conjugated polymers based on N‐benzoyldithieno [3,2‐b:2′,3′‐d]pyrrole and diketopyrrolopyrrole toward organic photovoltaic cell application

In this research, new donor–acceptor (D‐A) photovoltaic polymers were synthesized from dithieno[3,2‐b:2′,3′‐d]pyrrole electron donor derivatives, including N‐benzoyldithieno[3,2‐b:2′,3′‐d]pyrrole and N‐(4‐hexylbenzoyl)dithieno[3,2‐b:2′,3′‐d]pyrrole, in combination with the electron deficient unit 2,5‐bis(2‐ethylhexyl)‐3,6‐di(thiophen‐2‐yl)‐2,5‐dihydropyrrolo[3,4‐c]pyrrole‐1,4‐dione via direct (hetero)arylation polymerization. The D‐A conjugated polymers obtained were characterized via ¹H NMR, gel permeation chromatography, Fourier transform infrared spectroscopy, DSC, XRD, photoluminescence and UV–visible methods. In addition, these D‐A polymers were used as activated layers in bilayer and bulk heterojunction structures for the fabrication of organic photovoltaic cells. © 2019 Society of Chemical Industry     

Ene‐Carbonyl Reductive Coupling for the Synthesis of 3,3‐Disubstituted Phthalide, 3‐Hydroxyisoindolin‐1‐one and 3‐Hydroxyoxindole Derivatives

An efficient method for the synthesis of three classes of heterocyclic derivatives such as 3,3‐disubstituted phthalides, 3‐hydroxyisoindolin‐1‐ones and 3‐hydroxyoxindoles, is reported. In the presence of the simple reductive system, zinc (Zn)/ammonia (NH₃) [or zinc‐copper (Zn‐Cu)/ammonia], a wide range of alkenes including acrylates, acrylonitrile, acrylamide and vinyl sulfoxide underwent reductive coupling with methyl 2‐acylbenzoates and subsequent lactonization to provide 3,3‐disubstituted phthalides in good to high yields at ambient temperature. In a similar manner, 3‐hydroxyisoindolin‐1‐one and 3‐hydroxyoxindole derivatives could also be easily prepared by direct reductive coupling of phthalimides and N‐substituted isatins with activated alkenes, respectively. Application of this methodology towards the synthesis of 1‐naphthol derivatives on a gram scale is also depicted. Furthermore, the intramolecular phthalimides–ene reductive coupling afforded the respective cyclization products with high diastereoselectivity.

     

Study on the Reactions of 3-Benzoyl-2,4,5-pyrrolidinetrione with aliphatic diamines,phenylhydrazine, semicarbazide and guanidine derivatives

3-Benzoyl-2,4,5-pyrrolidinetrione ( 1a , b ) with aliphatic diamines, phenylhydrazine, semicarbazide, and guanidine derivatives yields mono and binary salts ( 4 , 7 , 10 , 11 - 14 ), enamines ( 2 , 3 ), imine ( 5 ), pyrrolo[3,4-c]pyrazole ( 6 ) and pyrrolo [3,4-e][1,4]diazepine ( 8 ), respectively. The influence of the reagents basicity on the route of cyclocondensation is studied.