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Succinic acid diamides containing two pharmacophoric fragments, one of which is 2amino-pyrimidine, and the other, N-methylpiperazine, 2-aminopyrimidine, or substituted aniline moiety, were synthesized in two steps. The synthetic scheme included acylation of substituted (pyrimidin-2-ylamino)aniline or pyrimidin-2-amine with succinic anhydride and the subsequent acylation of another heterocyclic or aromatic amine with the resulting pyrimidine-substituted succinic acid monoamide. The key intermediate products in the synthesis are succinic acid anilides. The acylation heterocyclic or aromatic amines with substituted succinic acid monochloride or amidation of succinic acid benzotriazolyl ester gave the corresponding succinic acid diamides as potential inhibitors of enzymes mediating tumorigenic processes. [ABSTRACT FROM AUTHOR]

We have developed a short and highly efficient microwave-enhanced protocol for the synthesis of new Schiff bases, (E)-N-[(2-arylimidazo[1,2-a]pyridine-3-yl)methylidene]pyridin-2-amines, by the condensa-tion of 2-arylimidazo[1,2-a]pyridine-3-carbaldehydes with 2-aminopyridine in polyethylene glycol-400 as a green reaction medium in the presence of a catalytic amount of acetic acid. The essential features of this protocol are enhanced reaction rate, more eco-friendly reaction conditions, high yields, and green aspects such as avoiding toxic catalysts and hazardous organic solvents and reuse of the reaction medium. [ABSTRACT FROM AUTHOR]

6,6-Dimethyl-5,6-dihydrobenzo[f]pyrrolo[2,1-a]isoquinoline-8,9-dione and its 1-(morpholine-4-carbonyl)-substituted analog reacted with ammonia, morpholine, aniline, and naphthalen-1-amine via opening of the dioxopyrrole ring to produce enamino keto amides. The reaction conditions depended on the nucleophile nature. Ammonia and morpholine readily reacted at 20°C, whereas the reaction with aromatic amines required heating in boiling glacial acetic acid. [ABSTRACT FROM AUTHOR]

The reaction of 5-substituted 4,4,4-trichloroacetylfuran-2,3-diones with aromatic amines resulted in the synthesis of 4-substituted 5-hydroxy-5-(trichloromethyl)dihydrofuran-2,3-diones, which showed antibacterial and antinociceptive activity. [ABSTRACT FROM AUTHOR]

2-Nitro-1H-benzo[f]chromenes reacted with alcohols to give a series of 3-alkoxy-2-nitro-2,3-dihy-dro-1H-benzo[f]chromenes as mixtures of cis and trans isomers. The reaction of 2-nitro-1H-benzo[f]chromenes with cyclic secondary amines and 3-amino-5,5-dimethylcyclohex-2-en-1-one displayed trans diastereoselec-tivity with the formation of Michael adducts with benzochroman structure. Conjugate addition of substituted anilines to the title chromenes afforded (2-hydroxynaphthalen-1-ylmethyl)-substituted β-nitroenamines. Nucleophilic dearomatization of 3-nitrobenzofurans by the action of primary aromatic amines involved aza- and retro-oxa-Michael reactions, which demonstrated a strong tendency of 3-nitrobenzofurans to undergo opening of the furan ring. [ABSTRACT FROM AUTHOR]

Recyclization of tetraoxathiaspiroalkanes and tetraoxathiocanes with primary amines (2- and 4-fluoroanilines, 3- and 4-chloroanilines, 2-methylaniline, 2- and 4-methoxyanilines, ammonium chloride) in the presence of samarium(III) nitrate hexahydrate afforded the corresponding cyclic azadiperoxides. N-(tert-Butyl)hexaoxaazadispirocycloalkanes underwent similar recyclization with 2-chloroaniline. The rate of the recyclization process depended on the nature of the heteroatom in the diperoxide ring (S > N > O). [ABSTRACT FROM AUTHOR]

New tetraoxaazadispiroalkanes have been synthesized by the three-component Mannich reaction of primary aromatic amines with geminal bis-hydroperoxides and cyclohexanone using Sm(NO3)3·6H2O as catalyst. [ABSTRACT FROM AUTHOR]

The mini-review systematizes recently published data on nucleophilic N- and C-amination of electron-deficient tropylium salts with aromatic amines. [ABSTRACT FROM AUTHOR]

The first nickel-catalyzed phosphorylation of aryltrimethylammonium tetrafluoroborates with the formation of C–P bond instead of C–N has been developed. Starting from easily available and inexpensive aromatic amines, a variety of important arylphosphonates have been synthesized in moderate to excellent yields. [ABSTRACT FROM AUTHOR]

Methyl N-alkyl-, N-cycloalkyl-, and N-arylcarbamates were synthesized by reaction of the corresponding amines with dimethyl carbonate in the presence of binder-free FeHY zeolite. The optimal conditions (reactant ratio, amount of the catalyst, temperature, reaction time) were found to afford the target products with high yields. [ABSTRACT FROM AUTHOR]

A preparative procedure was developed for the synthesis of 4-[5-(1-R-1H-indol-3-ylmethylidene)-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]butanoic acids which were converted to acid chlorides, and the latter reacted with aromatic and heterocyclic amines to afford a series of previously unknown 4-[5-(1H-indol-3-ylmethylidene)-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]butanamides. The synthesized compounds showed a moderate antitumor activity against most malignant tumor cells. UO31 renal cancer cell line turned out to be most sensitive to most of the tested compounds. [ABSTRACT FROM AUTHOR]

An ecofriendly, simple, and efficient one-pot protocol has been developed for the synthesis of 1,2,4,5-tetrasubstituted imidazoles by the reaction of benzil, aryl aldehydes, aliphatic or aromatic amines, and ammonium acetate, catalyzed by the acidic halogen-free ionic liquid [bmim]HSO4 under solvent-free conditions. The advantages of the proposed protocol include high yields, short reaction time, operational simplicity, and recyclability of the catalyst. Eight previously unknown tetrasubstituted imidazoles were synthesized, among which those bearing a cyclopropyl substituent on N1 can be considered as potential mutant isocitrate dehydrogenase 1 (IDH1) inhibitors. [ABSTRACT FROM AUTHOR]

An efficient procedure has been developed for the synthesis of N-aryl-1,5,3-dithiazocanes and 1,1′-biphenylenebis(1,5,3-dithiazocanes) by heterocyclization of N1,N1,N7,N7-tetramethyl-2,6-dithiaheptane-1,7-diamine with aromatic amines or 4,4′-methylene(or sulfonyl)dianiline in the presence of Sm(NO3)3·6H2O as catalyst. [ABSTRACT FROM AUTHOR]

The possibility of use of polynuclear aromatic amines as N-nucleophiles in the ipso-substitution of the 5-cyano group in 1,2,4-triazines has been studied. The influence of the structure of the aromatic amine on the result of the reaction has been demonstrated. With 3-aminobiphenyls the corresponding 5-amino-N-(biphenyl-3-yl)-1,2,4-triaizines have been obtained with yields of up to 88%. [ABSTRACT FROM AUTHOR]

New copper nanocatalyst was prepared by coating Fe3O4 magnetic nanoparticles with tetraethyl orthosilicate (TEOS), followed by functionalization with 3-chloropropyl(trimethoxy)silane and 4H-1,2,4-tri-azol-4-amine and complexation with copper(II) chloride. The new catalyst was characterized by various spectroscopic methods and was successfully used in the synthesis of 1-aryl-1H-tetrazoles by reaction of aromatic amines with sodium azide and triethyl orthoformate under solvent-free conditions at 100°C. [ABSTRACT FROM AUTHOR]

Reactions of 4-arylamino-2-tert-butyl-5-oxo-2,5-dihydrofuran-2-yl acetates with an equimolar amount of aromatic or heterocyclic amine in toluene involves initial attack of the amine on the C2 atom of the furan ring, followed by opening of the furan ring and elimination of acetic acid to give N-aryl(hetaryl)-2-arylamino-5,5-dimethyl-4-oxohex-2-enamides. [ABSTRACT FROM AUTHOR]

A rapid and efficient catalytic approach has been proposed for the synthesis of dimethyl 2-[2-(aryl-amino)but-3-en-1-yl]- and 2-[2-(arylamino)-2-phenylethyl]malonates in good yields (49-95%) by ring-opening reaction of dimethyl 2-vinyl- and 2-phenylcyclopropane-1,1-dicarboxylates with arylamines in the presence of Yb(III) catalyst under microwave irradiation. The synthesized compounds are convenient precursors to γ-(aryl-amino)butyric acid derivatives. [ABSTRACT FROM AUTHOR]

Acyclic diaminodiperoxides and cyclic azadiperoxides are synthesized by the reaction of 1,1-bis-(hydroperoxy)cycloalkanes with formaldehyde and primary arylamines in the presence of Sm-containing catalysts [SmCl3·6H2O, Sm(NO3)3·6H2O, SmCl3/γ-Al2O3, and Sm(NO3)3/γ-Al2O3]. The chemoselectivity of this three-component reaction depends on the position of the substituent (F,Cl) in the phenyl ring of the primary arylamines. Signals of the cyclic aminoperoxides were assigned considering the conformation dynamics of the tetraoxazocane cycle with two rigid peroxide bonds. The structure of the acyclic diaminodiperoxides was reliably determined by X-ray diffraction analysis. The synthesized acyclic diaminodiperoxides were found to exhibit anticancer activity. [ABSTRACT FROM AUTHOR]

Oxidative coupling of 6,7,8,9,9a,10,11,12,13,14-decahydro-5H-benzimidazo[2,1-e]acridine with reagents containing a primary aromatic amino group forms p-quinone diimines of the 2H-benzimidazo[2,1-e]-acridine series. The subsequent acid-activated 1,4-nucleophilic addition reaction of the products with the same reagents followed by autooxidation gives rise to 3-arylamino-substituted quinone diimines of the specified series. [ABSTRACT FROM AUTHOR]

6,14,22-Triaryl-2,4,8,10,12,16,18,20,24-nonathia-6,14,22-triaza-1,3,9,11,17,19(1,4)-hexabenzocyclotetracosaphanes are synthesized in high yield and selectivity by cycloaminomethylation of 4,4′-thiodibenzenethiol with N,N-bis(methoxymethyl)-N-arylamines in the presence of a Sm(NO3)3·6H2O catalyst. [ABSTRACT FROM AUTHOR]

N-Aryl(benzyl)adamantane-1-carboxamides were synthesized in 54–87% yields by reaction of adamantane-1-carboxylic acid with aromatic amines in the presence of phosphorus trichloride, 4-dimethylaminopyridine, and triethylamine on heating at 80°C for 8 h. [ABSTRACT FROM AUTHOR]

One-pot tandem synthesis was developed for substituted quinolines (in up to 97% yields) involving a selective catalytic oxidation of primary amines to aldehydes and their condensation with arylamines under the action of a dispersion of Fe(CrO2)2 and water solution of H2O2 at room temperature. The stage of catalytic oxidation of alcohols was accelerated by photoactivation. A presumable mechanism of the photoactivated tandem synthesis of 2-methylquinoline was suggested. Catalyst Fe(CrO2)2 was prepared by photochemical synthesis. [ABSTRACT FROM AUTHOR]

The article presents a study which focuses on the synthesis and antibacterial activity of N- and O-acylation products of primary aromatic amines and aminoalkanols. Noted is the treatment of the solution with potassium carbonate subsequent to its cooling process. Explored is mixture of the solution with hydrogen chloride or methyl iodide as well as with diethyl ether.

A procedure has been developed for the synthesis of dialkyl (5 E)-5-(2-alkoxy-2-oxoethylidene)-4-hydroxy-2,2-dimethyl-1-(4-methylphenyl)-2,5-dihydro-1 H-pyrrole-3-carboxylates by three-component condensation of dialkyl 3,4-dihydroxyhexa-2,4-dienedioate with acetone and p-toluidine. The structure of the products is discussed on the basis of the IR, H NMR, and X-ray diffraction data. [ABSTRACT FROM AUTHOR]

Depending on the reactant structure, reactions of substituted 3-(2-phenylpyrimidin-5-yl)propanoic acids with 2-aminopyridine, p-toluidine, and 2-aminophenol in polyphosphoric acid afforded the corresponding N-(pyridin-2-yl)propanamides, 5-[2-(benzoxazol-2-yl)ethyl]pyrimidine, and pyrido[2,3- d]pyrimidinones. [ABSTRACT FROM AUTHOR]

Pivalic acid was used as a solvent for aminolysis of poly-substituted 2-(nitroamino)-pyrimidin-4(3 Н)-one derivatives with arylamines of low basicity. The reaction did not occur in the other solvents or without solvent. Aminolysis products were obtained in 51-59% yields. [ABSTRACT FROM AUTHOR]

Acid-catalyzed Claisen aromatic rearrangement of ethyl N-(pent-3-en-2-yl)- N-phenylglycinate leads to the formation of ethyl N-[2-(pent-3-en-2-yl)phenyl]glycinate. The reaction of sodium salt of N-acetyl-2-(pent-3-en-2-yl)-4-methylaniline with methyl bromoacetate afforded ethyl N-acetyl- N-[4-methyl-2-(pent-3-en-2-yl)phenyl]glycinate. The hydrolysis of synthesized esters, the conversion of the obtained acids by treating with ethyl chloroformate into munchnones, and the subsequent [3+2]-cycloaddition provided methoxazoloquinoline structures. [ABSTRACT FROM AUTHOR]

New 7-aryl(hetaryl)-7,8,9,10,11,12-hexahydropyrimido[5,4- b][1,7]phenanthroline-9,11-diones have been synthesized by three-component condensation of barbituric acid with quinolin-5-amine and aromatic or heteroaromatic aldehydes. [ABSTRACT FROM AUTHOR]

Methyl 1-aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1 H-pyrrole-2-carboxylates reacted with methyl 2-arylamino-4-(2-naphthyl)-4-oxobut-2-enoates to give methyl 1,7-diaryl-4-aroyl-3-hydroxy-9-(2-naphthalen-2-ylcarbonyl)-2,6-dioxo-1,7-diazaspiro[4.4]nona-3,8-diene-8-carboxylates. [ABSTRACT FROM AUTHOR]

Catalytic amination of 7-hydroxy-6-cyanocoumarin or 7-hydroxy-6-methoxycarbonylcoumarin triflates with substituted anilines, isoquinolin-5-amine, 1 H-pyrazol-3-amine, or amino acids of penicillin series affords the corresponding 7-( N-substituted) aminocoumarins. In the amination of the mentioned triflates and also of peuruthenicine tosilate with 2-(piperidin-1-yl)aniline the catalytic system Pd(OAc)-BINAP has been efficient. [ABSTRACT FROM AUTHOR]

Reactions of p-(pent-4-enyloxy)aniline with salicylaldehyde containing versatile substituents in the positions 3 and 5 in an open system without solvent at 130°C afforded a series of ( N-aryl)salicylaldimines, which with TiCl(OPr- i) formed complexes of titanium(IV) dichloride LTiCl. [ABSTRACT FROM AUTHOR]

α-Amino nitriles containing a primary amino group undergo transamination with aliphatic and aromatic amines under mild conditions with high yields. A probable reaction mechanism involving intermediate elimination of cyanide ion has been proposed. [ABSTRACT FROM AUTHOR]

Efficient synthetic procedure was developed for 3-aryl(hetaryl)-1,5,3-dioxazepanes consisting in the transamination of 3- tert-butyl-1,5,3-dioxazepane with arylamines and also by the reaction of 1,2-ethanediol with N,N-bis(methoxymethyl)aryl(hetaryl)amines in the presence of catalytic amounts of Sm and Co compounds. [ABSTRACT FROM AUTHOR]

A simple and highly efficient procedure has been proposed for the synthesis of heterocyclic and aromatic N-benzyl amines via reductive amination of substituted aromatic aldehydes in the presence of sodium tetrahydridoborate-acetic acid system generating reactive sodium triacetoxyhydridoborate. [ABSTRACT FROM AUTHOR]

2-Substituted 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydroquinoline-4-carboxylic acids were synthesized by reaction of acyl- and aroylpyruvic acids with 3-amino-5,5-dimethylcyclohex-2-en-1-one. A plausible mechanism of their formation was proposed on the basis of ab initio quantum-chemical calculations. [ABSTRACT FROM AUTHOR]

Efficient procedures were developed for the synthesis of N-aryl-1,5,3-dithiazepanes and N-aryl-1,5,3-dithiazocanes by cyclocondensation of anilines with formaldehyde and α,ω-dithiols (etane-1,2-dithiol and propane-1,3-dithiol), as well as by transamination of N-tert-butyl-1,5,3-dithiazepane or N-tert-butyl-1,5,3-dithiazocane with aromatic amines in the presence of samarium and cobalt complexes. [ABSTRACT FROM AUTHOR]

5-Phenyl( p-tolyl)isoxazole-3-carboxylic acids were synthesized starting from 3-hydroxyiminomethyl-5-phenyl( p-tolyl)isoxazoles, and their reactions with p-hydroxybenzaldehyde, vanillin, isovanillin, o-vanillin, and ethyl vanillin gave the corresponding esters. The latter were brought into condensation with aromatic amines to obtain Schiff bases which were reduced to amines. [ABSTRACT FROM AUTHOR]

New carboxylic acid amides containing an N-methylpiperazine fragment were synthesized by reactions of 1-methylpiperazine or 3- and 4-(4-methylpiperazin-1-ylmethyl)aniline with 4-chlorobenzoyl chloride and of 4-methyl-3-nitroaniline with 4-(4-methylpiperazin-1-ylmethyl)benzoyl chloride or benzotriazol-1-yl 4-(4-methylpiperazin-1-ylmethyl)benzoate. 4-Chloro- N-[4-(4-methylpiperazin-1-ylmethyl)phenyl]benzamide reacted with imidazole, quinolin-5-amine, and 2-methylquinolin-5-amine to give substituted 4-amino- N-[4-(4-methylpiperazin-1-ylmethyl)phenyl]benzamides. 4-Methyl-3-nitrophenyl-4-methylpiperazin-1-yl-substituted benzamides were reduced with hydrazine hydrate over Raney nickel to obtain N-(3-amino-4-methylphenyl)-4-(4-methylpiperazin-1-ylmethyl)benzamide as key intermediate in the synthesis of antileukemic agent imatinib and its isomer with alternative position of the amide group, 4-[(3-amino-4-methylphenylamino)methyl]phenyl-(4-methylpiperazin-1-yl)methanone. [ABSTRACT FROM AUTHOR]

A novel procedure has been developed for selective synthesis of N-aryl-1,3,5-dithiazinanes, 1,2,6,7-tetrahydro-3,5,1,7-benzodithiadiazonine, and 6,7-dihydro-1,3,5,7-benzotrithiazonine by reactions of aniline derivatives with N-methyl-1,3,5-dithiazinane or 1,3,5-trithiane in the presence of transition and rare earth metal salts and complexes. [ABSTRACT FROM AUTHOR]

By Heck reaction of isoalantolactone with aryl bromides or aryl iodides (3a R,4a S, 8a R,9a R,E)-3-arylmethylidene-8a-methyl-5-methylidenedecahydronaphtho[2,3- b]furan-2(3 H)-ones and (4a S,8a R,9a S)-3-arylmethyl-8a-methyl-5-methylidene-4a,5,6,7,8,8a,9,9a-octahydronaphtho[2,3- b]furan-2(4 H)-ones, products of the double bond shift, were synthesized. The yields of the arylation products depend on the nature of the catalytic system and on the structure of the aryl halide. The structures of (3a R,4a S,8a R,9a R, E)-3-(3,4-dimethoxybenzylidene)-8amethyl-5-methylidenedecahydronaphtho[2,3- b]furan-2(3 H)-one and (4a S,8a R,9a S)-3-(2-methylsulfanylbenzyl)-8amethyl-5-methylidene-4a,5,6,7,8,8a,9,9a-octahydronaphtho[2,3- b]furan-2(4 H)-one were proved by XRD analysis. [ABSTRACT FROM AUTHOR]

ylation of thiophene and phenol with 3,4,4-trichloro-3-butenoyl chloride afforded the corresponding 1-(thien-2-yl)- and 1-(4-hydroxyphenyl)-3,4,4-trichloro-3-buten-1-ones, whose reaction with amines led to the formation of 3-amino-1-(thien-2-yl, 4-hydroxyphenyl)-4,4-dichloro-2-buten-1-ones The heterocyclization of the initial ketones into pyrazole structure was not observed, and the reaction with hydrazine hydrate provided bispyrazole products, N,N′-bis(5-thien-2-yl)- and N,N′-bis[5-(4-hydroxyphenyl)-1 H-pyrazol-3-ylmethylene]hydrazines. [ABSTRACT FROM AUTHOR]

Various spirocyclic derivatives of 1,2,3,4-tetrahydrobenzo[ f]quinoline containing substituents in the positions 2 and 4 of the ring were obtained by one-pot multicomponent condensation of available N-benzyl-2-naphthylamines, formaldehyde, and cyclic β-diketones of cyclohexanedione series. [ABSTRACT FROM AUTHOR]

The preparation of N-(oxiran-2-ylmethyl)- N-ethylaniline was developed. The compound was used in the synthesis of new N-derivatives of aromatic amines containing vicinal aminoalcohol moieties. [ABSTRACT FROM AUTHOR]

Mannich condensations of isophorone (3,5,5-trimethylcyclohex-2-en-1-one) with paraformaldehyde and dimethylamine, benzylamine, and piperidine hydrochlorides were studied. The reactions were not selective, and they involved both activated methylene group and vinylic carbon atom, as well the exocyclic methyl group at the double bond. The corresponding isomeric amino ketones were formed in comparable amounts (42, 30, and 28%). The E and Z isomers of isophorone oxime reacted with paraformaldehyde and dimethylamine hydrochlride to give mixtures of analogous Mannich condensation products, but the fraction of the addition product at the carbon atom spatially close to the oxime hydroxy group was larger. Under analogous conditions, the reaction of isophorone with aromatic amines and aromatic aldehydes gave products of two-component condensation of isophorone with aldehydes, and the reactions involved exclusively the activated methylene group in the initial enone with formation of the corresponding trans,trans-isomeric 7-arylmethylidene derivatives. [ABSTRACT FROM AUTHOR]

The reactions of methyl 2,4-dioxo-4-phenylbutanoate and methyl 2,4-dioxopentanoate with a mixture of an aromatic aldehyde and propane-1,2-diamine, depending on the initial reactant ratio, gave 4-acyl-1-(2-aminopropyl)-5-aryl-3-hydroxy-2,5-dihydro-1 H-pyrrol-2-ones and 1,1′-(propane-1,2-diyl)bis(4-acetyl-3-hydroxy-5-phenyl-2,5-dihydro-1 H-pyrrol-2-one). Reactions of substituted 1-(2-aminopropyl)-2,5-dihydro-1 H-pyrrol-2-ones with aromatic amines and hydrazines were studied, and the structure of one of the products, 5-(2-aminopropyl)-3,4-diphenylpyrrolo[3,4- c]pyrazol-6-one, was proved by X-ray analysis. [ABSTRACT FROM AUTHOR]

Reactions of isopropyl 2-(1-aryl-4,5-dioxo-2-phenyl-4,5-dihydro-1 H-pyrrol-3-yl)-2-oxoacetates with aromatic amines involve a pyrroledione-pyrroledione recyclization to form isopropyl 1-aryl-2-hydroxy-4,5-dioxo-3-[phenyl(arylamino)methylene]pyrrolidine-2-carboxylates. The crystal and molecular structure of ( Z)-isopropyl 2-hydroxy-4,5-dioxo-1-phenyl-3-[phenyl(phenylamino)methylene]pyrrolidine-2-carboxylate was proved by XRD analysis. [ABSTRACT FROM AUTHOR]

The rules were investigated of the regioselective synthesis of N2-substituted derivatives of 2-amino-6-benzyl-5-methylpyrimidin-4(3 H)-one from 6-benzyl-5-methyl-2-(methylsulfanyl) pyrimidin-4(3 H)-one. [ABSTRACT FROM AUTHOR]

Previously unknown 1-[2-aryl(quinolin-2-yl)ethenyl]-3-[aryl(quinolin-2-yl)]benzo[ f]quinolines and 3-aryl-1-(2-arylethenyl)-4,7-phenanthrolines were synthesized by reactions of 1-methylbenzo[ f]quinolines and 1-methyl-4,7-phenanthrolines with substituted N-benzylideneanilines and N-(quinolin-2-ylmethylidene)aniline on heating in dimethylformamide in the presence of potassium hydroxide. [ABSTRACT FROM AUTHOR]

The oxidative coupling of primary aliphatic and aromatic amines with 3,4,4a,5-tetrahydropyrido[1,2- a]-benzimidazole derivatives resulted in the formation of p-quinone diimines of the given series. [ABSTRACT FROM AUTHOR]

The reaction of chloroacetyl chloride with 1,2-dichloroethene in the presence of AlCl3 unexpectedly led to the formation of ( E)-1,1,4-trichlorobut-3-en-2-one whose structure was proved by 1H and 13C NMR, IR, and mass spectra and independent synthesis. A probable reaction scheme was proposed, which involves transformation of initially formed 1,2,4-trichloro-3-oxobutan-2-yl cation by the action of AlCl3. The high reactivity of the vinylic halogen atom in ( E)-1,1,4-trichlorobut-3-en-2-one was demonstrated by its reactions with nitrogen-centered nucleophiles (triethylamine, aniline, 3,5-dimethyl-1 H-pyrazole) and sodium sulfide. These reactions involved only the C-Cl bond in the vinyl fragment and afforded (4,4-dichloro-3-oxobut-2-en-1-yl)triethylammonium chloride, 1,1-dichloro-4-phenylaminobut-3-en-2-one, 1-(4,4-dichloro-3-oxobut-2-en-1-yl)-3,5-dimethyl-1 H-pyrazole, and 4,4′-thiobis(1,1-dichlorobut-3-en-2-one), respectively. The reaction of 1,1,4-trichlorobut-3-en-2-one with benzylhydrazine gave a mixture of 1,3- and 1,5-disubstituted pyrazoles. [ABSTRACT FROM AUTHOR]