Search

It is found that methyl silica turned into a hydrated state in the presence of water upon action of mechanical loads. In this case a significant amount of water can be transformed into a weakly associated form. In such state the water molecules do not participate in the formation of hydrogen bonds acquiring certain properties of supercritical water; in particular a capacity to form concentrated solutions with weakly polar substances. It is shown that the total interphase energy of strongly and weakly associated water increased under the influence of mechanical loads, which was caused by the change in the morphology of the interparticle space of methyl silica in the process of hydraulic sealing, the amount of the water in small clusters increased. [ABSTRACT FROM AUTHOR]

It was found that composite systems with succinic acid, in which a significant part of the acid is in the voids between the particles of silica while the acid is in the form of nano- and microcrystalites, can be obtained from hydrophilic and hydrophobic silicas and their mixtures by the method of dosing mechanical loading. The textural characteristics of the composites depend on their composition, the mechanical load, and the humidity during their creation. Both hydrophilic and hydrophobic systems can be transferred to an aqueous medium and used in medicine and biotechnology. [ABSTRACT FROM AUTHOR]

A procedure is developed for bringing hydrophobic nanosilica (neat and modified with succinic acid) into a wet state where the amount of the water bound to the material is comparable to the weight of the silica, and the apparent density is 0.7–1 g/cm3. The obtained composite is studied via low-temperature 1H NMR spectroscopy, X-ray powder diffraction analysis, and thermogravimetry. It is shown that the bonding of water to hydrophobic silica is more efficient than the bonding of water to a water-based composite with hydrophilic succinic acid. It is concluded that under mechanical loads, small (less than 10 nm) clusters of water form in the intergranular gaps in silica and interact with the hydrophobic surface via van der Waals interactions. [ABSTRACT FROM AUTHOR]

The state of water in hydrogels of sodium carboxymethylcellulose and bentonite was studied by low-temperature PMR spectroscopy. Polymer macromolecules interacted actively with the bentonite. The thermodynamic parameters of layers of strongly and weakly bound water and the interphase energy of water in the hydrogels were determined. [ABSTRACT FROM AUTHOR]

The hydrated layer of composite particles prepared using Al 2O 3 and cattle vitreous humor was investigated using NMR spectroscopy. It was found that water bound to Al 2O 3 nanoparticles was present in the form of clusters with different degrees of association and energies of interaction with the surface. Water bound to the surface of the Al 2O 3/vitreous humor composite became more uniform upon immobilization of vitreous humor components on the surface of the Al 2O 3. With this, the clusters of adsorbed water had characteristics that were close to those found in air and weakly polar CHCl 3 media. Addition of polar CH 3CN led to the formation of very small water clusters. PMR spectra of the surface of the Al 2O 3/vitreous humor composite in the presence of trifluoroacetic acid differentiated four types of hydrated structures that differed in the degree of water association. [ABSTRACT FROM AUTHOR]

Three sets of activated carbons (ACs) were prepared with the same precursor but activated differently (by CO or water vapour) with various burn-off levels. The ACs demonstrate increased deviation of the pore shape from the slitshaped model with increasing burn-off and contributions of pores of different sizes depending on the activation type. Significant re-arrangement of adsorption complexes, especially of the Van der Waals type characteristic for nonpolar or weakly polar adsorbates (H, CH, CHCl, CHCl), occurs in both micropores and mesopores of ACs with decreasing temperature. The behaviour of their mixtures with water and DMSO can strongly differ from that of individual adsorbates. [ABSTRACT FROM AUTHOR]

The alkylation of derivatives of 3-aminoisoquinolin-1(2H)-one in the presence of NaH may proceed in three directions: 1) at the carbonyl group oxygen atom, 2) at the nitrogen atom N-2, and 3) at the 3-amino group. The reaction of equivalent amounts of the reagents gives predominantly products of substitution at the 3-amino group. Repeated alkylation proceeds at the lactam fragment to give a mixture of O-alkyl and N-alkyl derivatives. Acylation of 3-dialkylamino- and 3-alkylanilinoisoquinolin- 1(2H)-ones in the presence of NaH gave derivatives of 3-amino-1-isoquinolinyl 4-ethoxybenzoate. [ABSTRACT FROM AUTHOR]

The effect of the anticancer drug-doxorubicin (Dox) on hydration properties of a nanocomposite material deposited on silica and modified by small amount of DNA (0.6 wt%) was studied by means of H NMR spectroscopy at low temperatures (in the range of 200-280 K). Signals of either weakly (WAW) or strongly (SAW) associated water, as well as water associated with electrondonor groups of the composite surface (ASW), were observed. The findings reveal that, depending on the temperature and the composition of the dispersion medium, fast molecular exchange takes place between different forms of interphase water. The presence of Dox (0.1-0.2 wt%) in the dispersion medium leads to change of the relative concentrations of different forms of water. [ABSTRACT FROM AUTHOR]

Reactions of bicyclo[2.2.1]hept-5-en- endo-2-ylmethanamine with phenyl, 4-methylphenyl, 3-methylphenyl, 2-methylphenyl, 4-methoxyphenyl, cyclohexyl, and cyclohexenyl 2,3-epoxypropyl ethers gave the corresponding N-mono- and N, N-bis(3-R-oxy-2-hydroxypropyl) derivatives. The structure of the newly synthesized amino alcohols and regioselectivity of oxirane ring opening were determined by IR spectroscopy, H and C NMR, and mass spectrometry. The reaction mechanism was studied by quantum chemistry at the PCM/B3LYP/6-31G( d) level of theory. [ABSTRACT FROM AUTHOR]

2-Arylmethyl- and 2-arylmethyl-3-methyl-substituted 3,4-dihydrothieno[3,4-d]pyrimidin-4-ones were synthesized starting from 2-cyanomethylbenzoic acid and methyl 3-amino-4-thiophenecarbonate, obtained in situ from its hydrochloride by a new method which gives an increased yield of the desired products. The physicochemical properties and the biological potential of the compounds synthesized have been compared with analogous substituted 2,3-dimethylthieno[2,3-d][pyrimidinones, thieno[3,2-d]pyrimidinones, and their benzene isosteres. The differences associated with the position of the sulfur atom, are most clearly reflected in the electronic spectra. On the basis of calculated data, the transition from derivatives of 4-oxo-3,4-benzopyrimidines to their analogous thieno isosteres leads to changes in the profiles of their biological activities. [ABSTRACT FROM AUTHOR]

Derivatives of the previously unknown tetracyclic system 4H-thieno[3′,4′:5,6]pyrimido[1,2-b]iso-quinoline-4,11(5H)-dione have been synthesized. A comparison of the spectral characteristics and the biological activities of these compounds has been carried out, and also of their positional isomers and benzene isosteres. The differences, associated with the position of the sulfur atom, are most reflected in their electronic spectra. [ABSTRACT FROM AUTHOR]

We have used low-temperature 1H NMR spectroscopy to determine the thermodynamic characteristics of water bound to OX-50 nanosilica (SBET ≈ 50 m2/g) in different media: aqueous, air, chloroform medium, and gaseous methane. We demonstrate the difference between the hydration parameters of silica OX-50 on going from an aqueous suspension to a hydrated powder. We present the water cluster size distributions in the studied systems, calculated from the Gibbs–Thomson equation. We found that the average water cluster size in suspension is considerably larger than the cluster sizes in hydrated powders. [ABSTRACT FROM AUTHOR]

(Z)-4-Bromo-1,3-di(2-thienyl)-2-buten-1-one was obtained by the bromination of 1,3-di(2-thienyl)-2-buten-1-one by NBS in anhydrous CCl. The starting butanone was obtained by the condensation of 1-(2-thienyl)-1-ethanone by the action of SOCl. The reaction of (Z)-4-bromo-1,3-di(2-thienyl)-2-buten-1-one with tertiary amines such as EtN, pyridine, 1-alkyl-1,3-diazole, 1-alkylbenzimidazole, and 1-alkyl-1,2,4-triazole leads to quaternary salts. The azolium salts cyclize by the action of base to give di(2-thienyl)azolo[a]pyridinium derivatives. 3-Methyl-6,8-di(2-thienyl)[1,3]thiazolo[3,2-a]pyridin-4-ium and 2,4-di(2-thienyl)pyrido[2,1-b]benzothiazol-10-ium bromides were obtained by the same procedure but without separating the intermediate quaternary salts. [ABSTRACT FROM AUTHOR]

A glycidyl fragment was introduced into molecules of derivatives of bicyclo[2.2.1]hept-5-en- endo-2-ylmethylamine (sulfonamides, sulfonylurea) under the conditions of phase-transfer catalysis; carboxamides were established to be passive in this reaction; the results were compared with the calculations of the proton affinity of the nitrogen atoms in the molecules of the acyl derivatives of the framework amine. Products were obtained from reactions of N-(4-chlorophenylsulfonyl)- N-(glycidyl)bicyclo[2.2.1]hept-5-en- endo-2-ylmethylamine with benzylamine, N-benzylpiperazine, and bicyclic framework amines. The regiochemistry of the aminolysis was investiganted with the help of NMR 1H, 13C spectra, and also with the use of 2D spectra COSY, NOESY, HMQC, HMBC. [ABSTRACT FROM AUTHOR]

ylation of 3-amino-1(2H)-isoquinolinone may proceed at three points - at the oxygen atom of the carbonyl group, at the nitrogen atom of the 3-amino group, and at the carbon atom in position 4 of the isoquinolinone fragment. Factors influencing the results of the reactions have been determined, and conditions have been found for the synthesis of three types of products - 4-(acyl)-3-(R-amino)-1(2H)-isoquinolinones, N-(1-oxo-1,2-dihydro-3-isoquinolinyl)-R-amides, and esters of 3-(R-amino)-1-iso-quinolinol. [ABSTRACT FROM AUTHOR]

The accessible two-center electrophilic substrate 4-tosyl-2-phenyl-5-chloro-1,3-thiazole reacts regioselectively with N-, O-, and S-nucleophiles to eliminate a chloride ion. The analog of this substrate, 4-tosyl-2-phenyl-5- p-chlorophenylsulphonyl-1,3-thiazole, reacts with “soft” and “hard” nucleophiles differently: with the participation of C5 or C4 center, respectively, that seems to be caused by the principle of “symbiosis” in the transition state. [ABSTRACT FROM AUTHOR]

NMR spectroscopy showed that treatment of 1-allyl-3-[(arylamino)methylene]quinoline-2,4-(1H,3H)-diones with an equivalent amount of dry bromine in anhydrous acetic acid leads to the formation of 4-aryliminomethyl-2-bromomethyl-5-oxo-1,2-dihydro-5H-oxazolo[3,2-a]quinolinium bromides. [ABSTRACT FROM AUTHOR]

A method for the synthesis of derivatives of [1, 3]thiazolo[3,2- a]pyridines, pyrido[2,1- b][1, 3]benzo-thiazole, [1, 3, 4]thiadiazolo[3,2- a]pyridine, and [1, 2, 4]triazolo[4,3- a]pyridine, which includes base initiated cyclization of quaternary azolium salts, formed by the interaction of ( Z)-1,3-diaryl-4-bromo-2-buten-1-ones with 1-alkyl-1H-1,2,4-triazoles, 4-methyl-1,3-thiazole, 1,3-benzothiazole, and N-phenyl-1,3,4-thiadiazole-2-amine. Derivatives of 2-chloroimidazo[1,2-a]pyridine were obtained when 5-chloro-1-methyl-1H-imidazole was used. [ABSTRACT FROM AUTHOR]

Reaction of the available 1-tosyl-2,2-dichloroethenyl isothiocyanate with sodium cyanide yields new clearly electrophilic substrate of thiazole nature containing the nitrile group, the tosyl residue, and the chlorine atom at C2, C4, and C5 respectively. The direction of the reaction of this substrate with nucleophile depends significantly on the nature of the latter. It was used in regioselective syntheses of a series of the unknown previously trifunctional thiazoles. [ABSTRACT FROM AUTHOR]

The interaction of (Z)-1,3-diaryl-4-bromo-2-buten-1-ones with 1-substituted (benz)imidazoles in benzene gave (Z)-1-R-3-(2,4-diaryl-4-oxo-2-butenyl)-1H-imidazolium bromides and (Z)-1-R-3-(2,4-diaryl-4-oxo-2-butenyl)-1H-benzimidazolium bromides which readily cyclize in the presence of base to form derivatives of 7,9-diarylpyrido[1,2-a]benzimidazole and 6,8-diarylpyrimidazo[1,2- a]pyridine. The effects of the nature of substituents in the benzene ring of the diarylbutenones and the substituent at N(1) in the (benz)imidazoles on the alkylation and cyclization reactions has been studied. The optimum conditions for the synthesis of the 5-R-4-hydroxy-2,4-diphenyl-4,5-dihydro-1H-pyrido[1,2- a]benz-imidazol-10-ium, 5-R-2,4-diaryl-4-hydroxy-4,5-dihydro-3H-pyrido[1,2-a]benzimidazol-10-ium, and 5-R-2,4-diaryl-5H-pyrido[1,2-a]benzimidazol-10-ium have been found. [ABSTRACT FROM AUTHOR]

5-(4-Chlorophenyl)- and 5-phenylfuran-2(3 H)-ones reacted with guanidine carbonate at the methylene group in the unsaturated lactone molecule, leading to the formation of 4-(2-aryl-5-oxo-2,5-dihydrofuran-2-yl)-5-aryltetrahydrofuran-2-ones, while 5-(4-methylphenyl)furan-2(3 H)-one under analogous conditions gave rise to N,N′-bis[4-(4-methylphenyl)-4-oxobutanoyl]guanidine. The reactions of 5-arylfuran-2(3 H)- ones with thioacetamide afforded 4-aryl- N-{1-[5-aryl-2-oxo-2,3-dihydrofuran-3-ylidene]ethyl}-4-oxobutanamides. The corresponding N-(4-aryl-4-oxobutanoyl)thioureas were obtained by heating 5-arylfuran-2(3 H)-ones with thiourea. [ABSTRACT FROM AUTHOR]

The interaction of 2-chloroquinoline-3-carbaldehydes with 1H-benzimidazol-2-ylacetonitriles and 1-benzyl-1H-imidazol-2-ylacetonitrile has been studied. It was shown that products of condensation at the methylene group are formed under mild conditions. Carrying out the reaction under more forcing conditions leads to an intramolecular nucleophilic substitution of the chlorine atom and the formation of cyclic ionic compounds (in the case of N-substituted hetarylacetonitriles), which are subsequently dealkylated. [ABSTRACT FROM AUTHOR]

A three-component condensation of 1-allyl-4-hydroxy-2-oxo-1,2-dihydroquinoline, isatin, and malononitrile gave a satisfactory yield of 4,3'-spiro[(6-allyl-2-amino-5-oxo-5,6-dihydro-4H-pyrano-[3,2-c]quinoline-3-carbonitrile)-2'-oxindole], which structure was confirmed by X-ray analysis. [ABSTRACT FROM AUTHOR]

2-(3,5-Diaryl-1H-pyrazol-4-yl)-1H-benzimidazoles have been obtained by the cyclocondensation of 2-phenacyl-1H-benzimidazoles with 4-nitro- and 4-methoxybenzoylhydrazines. The reaction mechanism and the isomerism of the obtained products are discussed. According to the data of 1H NMR spectroscopy the stabilized isomer is that in which the electron-withdrawing aryl substituent is located in position 3 and the electron-donating substituent in position 5 of the pyrazole ring. [ABSTRACT FROM AUTHOR]

The presence of active methylene group in the molecules of cyclopenta[ c]quinolinium quarternary salts permitted to obtain products of their reaction with p-dimethylaminobenzaldehyde. Structures of the reaction products were established from 1H and 13C NMR spectral data using the correlation spectra. The effect of substituents at nitrogen on the visible absorption spectra was studied. The investigation of formation of the frontier orbitals in the reaction products by quantum chemical calculations revealed the reason of the coloration of the dyes synthesized. [ABSTRACT FROM AUTHOR]

Alkylidenehydrazides have been synthesized by the reaction of 1-R-4-hydroxy-2-oxo-1,2-dihydro-quinoline-3-carboxylic acid hydrazides with lower dialkyl ketones in order to reveal a structure-antitubercular activity relationship. It was shown by 1H NMR spectroscopy that hydrazones obtained from the unsymmetrical ketone – methyl ethyl ketone – exist primarily in the E-isomer form. It was found that the presence of two aliphatic substituents in the alkylidene fragment of the compounds investigated leads to a marked lowering of antimicobacterial properties. [ABSTRACT FROM AUTHOR]

Bromination of 1-allyl-substituted 3-(arylaminomethylene)quinoline-2,4-(1H,3H)-diones with one equivalent of molecular bromine in glacial acetic acid and subsequent dilution of the reaction mixture with water is accompanied by halocyclization and hydrolysis to form 2-bromomethyl-5-oxo-1,2 dihydro-5H-oxazolo[3,2-a]quinoline-4-carbaldehyde. [ABSTRACT FROM AUTHOR]

The reaction of 6-ethyl-8-formyl-7-hydroxy-3-(4-phenyl-4H-1,2,4-triazol-3-yl)chromone with 2-azolyl-acetonitriles gave 8-iminopyrano[2,3- f]chromen-4-ones, whose acid hydrolysis led to pyrano-[2,3- f]chromene-4,8-diones containing azaheterocyclic substituents at C-3 and C-9. [ABSTRACT FROM AUTHOR]

Phosphonium ylides stabilized by nitrile and 4,5-di(arylsulfonyl)-1,3-thiazol-2-yl fragments show biphilic reactivity. They react with aromatic aldehydes upon heating revealing a noticeable activity of ylide center and are condensed with typical nucleophiles at C4 center of the thiazole ring with the elimination of arylsulfonyl group under mild conditions. New 1,3-thiazole derivatives were obtained whose structures were proved by chemical, spectal and X-ray structural investigations. [ABSTRACT FROM AUTHOR]

The reaction of 3-amino- and 3-amino-5-methylthio-1,2,4-triazoles with cinnamaldehyde takes two directions to form mixtures of 5-[ N-(3-phenylpropenylideneamino)]-1 H-1,2,4-triazoles and 5-phenyl-4,5,6,7-tetrahydro[1,2,4]triazolo[1,5- a]pyrimidin-7-ols. [ABSTRACT FROM AUTHOR]

Treatment of γ-bromodypnone with arylhydrazines gives differently structured products, i.e. γ-bromo-dypnone hydrazones, 1-aryl-3,5-diphenyl-1,4-dihydropyridazines, 1-aryl-3,5-diphenyl-1,6-dihydro-pyridazines, and aromatic 1,3,5-triarylpyridazinium salts. We have studied the pattern of formation of all of the products and their properties. Heating an alcohol solution of 1,3,5-triphenyl-1,4-dihydro-pyridazine gives N,2,4-triphenyl-1H-pyrrole-1-amine or to a 1,3,5-triphenylpyridazinium salt dependent upon the acidity of the medium. The product of addition of HBr to the 1,6-dihydropyridazine system is 5-bromo-1-(4-nitrophenyl)-3,5-diphenyl-1,4,5,6-tetrahydropyridazine. [ABSTRACT FROM AUTHOR]

Condensation of 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carbaldehydes, thioglycolic acid (or methyl thioglycolate), and anilines does not lead to the synthesis of the corresponding thiazolidinylquinolones because the Schiff bases so formed exist exclusively in a form inert to enamine thioglycolates. 1H NMR spectroscopy showed that the main components of the isolated 3-arylaminomethylenequinoline-2,4-(1H,3H)-diones are E-isomers. The results of a study of the antitubercular properties of the compounds obtained are presented. [ABSTRACT FROM AUTHOR]

Reactions of bicyclo[2.2.1]hept-5-en- endo-2-ylmethanamine with N-(2,3-epoxypropyl)arenesulfonamides gave amino alcohols having a norbornene fragment and sulfonamide group. The major products were formed via opening of the oxirane ring according to the Krasuskii rule. The product structure was determined by 1H and 13C NMR spectroscopy using DEPT and two-dimensional COSY, NOESY, HMQC, and HMBC techniques. [ABSTRACT FROM AUTHOR]

An efficient method has been proposed for the preparation of a series of 3-O-acyl derivatives of naloxone. The features of the steric structure and NMR spectra are discussed. Pharmaceutical investigation has shown the promise within the synthesized compounds of creating opiate receptor antagonist compounds with prolonged action. [ABSTRACT FROM AUTHOR]

The direction of the reaction of 4-bromo-1,3-diphenyl-2-buten-1-one (γ-bromodypnone) with hydrazines depends on the nature of the substituent they contain. Reaction with 1-methylhydrazinium hydrosulfate gives 1-methyl-3,5-diphenylpyridazin-1-ium bromide but carboxylic acid hydrazides give N-(2,4-diphenyl-1H-pyrrol-1-yl)carboxylic acid amides. γ-Bromodypnone and phenylhydrazine give both 1,3,5-triphenyl-1,4-dihydropyridazine and N,2,4-triphenyl-1H-pyrrol-1-amine (15%). 1-(2,4-Dinitrophenyl)hydrazine gives the 2,4-dinitrophenylhydrazone of (Z)-4-bromo-1,3-diphenyl-2-buten-1-one. Condensation of 2,4-diphenyl-1H-pyrrol-1-amine with aromatic aldehydes readily leads to N-(arylmethylidene)-2,4-diphenyl-1H-pyrrol-1-amines and alkylation with methyl iodide gives N,N-dimethyl-2,4-diphenyl-1H-pyrrol-1-amine. [ABSTRACT FROM AUTHOR]

The reaction of ethyl 4-chloro-1-methyl-2-oxo-1,2-dihydroquinoline-3-carboxylate with p-toluene-sulfonylhydrazide at room temperature in the system DMSO/K2CO3 gives 5-methyl-2-(toluene-4-sulfonyl)-1,2-dihydro-5H-pyrazolo[4,3- c]quinoline-3,4-dione, alkylation of which using ethyl iodide gives the 1N-substituted derivative. [ABSTRACT FROM AUTHOR]

Accessible 2,2-dichloro-1- p-tolylsulfonylethenyl isothiocyanate reacted with hydrazine hydrate to give 5-chloro-2-hydrazino-4- p-tolylsulfonyl-1,3-thiazole whose reactions with thiols and amines followed a complicated pattern. Treatment of 5-chloro-2-hydrazino-4- p-tolylsulfonyl-1,3-thiazole with acetylacetone led to the formation of previously unknown 5-chloro-2-(3,5-dimethyl-1 H-pyrazol-1-yl)-4- p-tolylsulfonyl-1,3-thiazole which reacted with O-, S-, and N-centered nucleophiles at the C5 atom with high regioselectivity. [ABSTRACT FROM AUTHOR]

Reaction of 5-amino-3-methylpyrazole, 3-amino-, 5-amino-3-methylsulfanyl-1,2,4-triazole and 5-amino-1,2,4-triazole-3-thione with 3-phenylacryloyl-chloride under mild conditions is characterized by low selectivity and does not lead to the formation of fused heterocyclic systems but gives mixtures of products of mono- and diacylation of the nucleophilic sites in the molecules of α-aminoazoles. Endocyclic monoacyl derivatives of aminotriazoles in DMF undergo a transacylation at the exo-amino-group followed by cyclization into dihydro-1,2,4-triazolo[1,5- a]-pyrimidin-5-ones. [ABSTRACT FROM AUTHOR]

6-Allylsulfanyl-1-arylpyrazolo[3,4- d]pyrimidin-4(5 H)-ones react with iodine and sulfuric acid to give angular pyrazolothiazolopyrimidine derivatives. The reaction of 6-(prop-2-yn-1-ylsulfanyl)-1-(4-tolyl)-pyrazolo[3,4- d]pyrimidin-4(5 H)-one with sulfuric acid gives angularly fused pyrazolo[4,3- e][1,3]thiazolo-[3,2- a]pyrimidin-4-one, whereas in the reaction with sodium methoxide linearly fused pyrazolo[3,4- d][1,3]-thiazolo[3,2- a]pyrimidin-4-one was formed. Linearly fused pyrazolo[3′,4′:4,5]pyrimido[2,1- b][1,3]thiazole derivatives were also obtained by reaction of 1-aryl-6-(3-phenylprop-2-en-1-ylsulfanyl)pyrazolo[3,4- d]pyrimidin-4(5 H)-ones with sulfuric acid. [ABSTRACT FROM AUTHOR]

The reaction of 4-imino-1-methyl-5-phenyl-6-propargylthio-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidine with halogens leads to the formation of (Z)-8-halomethylene-4-imino-1-methyl-5-phenyl-4,5,7,8-tetrahydro-1H-pyrazolo[4,3-e][1,3]thiazolo[3,2-a]pyrimidinium trihalide. [ABSTRACT FROM AUTHOR]

Treatment of 5-aryl-3-halo-12H-isoquino[2,3-a]quinazolines with electrophilic reagents readily forms their oxidation products. Acylation of the 3-chloro-5-phenyl-7,12-dihydroisoquino[2,3-a]quinazolinium perchlorate with Ac2O in the presence of pyridine gave the product of electrophilic substitution at the C-7 atom 1-(3-chloro-5-phenyl-12H-isoquino[2,3-a]quinazolin-7-yl)-1-ethanone. By the same route phenacyl bromides react with the anhydro base 1 to give 5-aryl-7-(2-aryl-2-oxoethyl)-3-halo-isoquino[2,3-a]quinazolin-13-ium bromides. These salts readily react with nucleophilic reagents to form the products of addition at the C-12 atom. [ABSTRACT FROM AUTHOR]

Treatment of 2-(4-oxo-3,4-dihydrothieno[2,3-d]-and-[3,2-d]pyrimidin-2-ylmethyl)benzoic acids and 2-(4-oxo-3,4-dihydro-2-quinazolinylmethyl)benzoic acid with acetic anhydride gave thieno[3′,2′:5,6]-and-[2′,3′:5,6]pyrimido[1,2-b]isoquinoline-4,11-diones and isoquino[2,3-a]quinazoline-5,12-dione respectively. NMR spectroscopy showed that an intramolecular acylation of the above acids occurs at the atom N-1 of the pyrimidinone part of the bicycle. [ABSTRACT FROM AUTHOR]

2-(Benzenesulfonyl)-4-tosyl-1,3-thiazole was synthesized starting from the available 2,2-dichloro-1-tosylethenyl isothiocyanate. The product is a pronounced electrophilic substrate feasible for investigation of the order of nucleophilic substitution at the C2, C4, and C5 centers of the thiazole ring. Different nucleophilic agent first attack the C2 atom. After that S-nucleophiles react with C5, while O-and N-nucleophiles, with C4. [ABSTRACT FROM AUTHOR]

Condensation of aminopyrazine with triethyl methanetricarboxylate gave ethyl 2-hydroxy-4-oxo-4H-pyrazino[1,2-a]pyrimidine-3-carboxylate. According to X-ray analytical data the compound exists in the 2-hydroxy-4-oxo form in the crystal. [ABSTRACT FROM AUTHOR]

5-Aryl-7,12-dihydroisoquino[2,3-a]quinazolinium perchlorates are readily oxidized by atmospheric oxygen to form the products of oxidative coupling 5,5′-bis(aryl)-3,3′-dihalo[7,7′]bi[isoquino-[2,3-a]quinazoline-13,13′-diylium perchlorates. Heating 3-chloro-5-phenyl-7,12-dihydroisoquino-[2,3-a]quinazolinium perchlorate in nitrobenzene gives the 3-chloro-5-phenylisoquino[2,3-a]quinazolin-13-ium perchlorate. The aromatic 5-arylisoquino[2,3-a]quinazoline derivatives obtained react with nucleophilic reagents to form addition products at the C-12 atom. [ABSTRACT FROM AUTHOR]

The reaction of 4-bromo-1,3-diphenyl-2-buten-1-one with thiourea or N,N′-diphenylthiourea gives 2-(2-amino-4-phenyl-4,5-dihydro-1,3-thiazol-4-yl)-and 2-[3,4-diphenyl-2-(phenylimino)-1,3-thiazolidin-4-yl]-1-phenyl-1-ethanone — the products of nucleophilic substitution of the halogen atom and Michael addition at position 3 of the 2-buten-1-one system. A similar reaction with thiosemicarbazide and 1-phenylthiosemicarbazide gives the 4-(2-oxo-2-phenylethyl)-4-phenyl-and 4-(2-oxo-2-phenylethyl)-3,4-diphenyl-1,3-thiazolidin-2-one hydrobromides respectively. [ABSTRACT FROM AUTHOR]

Tetramethylene-2,2′-bis(1,3,3-trimethyl-(3H)-indolium),-3-ethylbenzothiazolium,-1-methyl-quinolinium, and-1-methyl-and-1-butylbenz[c,d]indolium salts were synthesized starting from them trimethinecyanines containing an ethylene bridging group in the α, α′-positions of the chromophore have been prepared. These compounds are converted to their analogs containing a vinylene group by the action of benzoquinones. In the case of thiacarbocyanines the effect of the indicated bridging groups on the conformation and protonation route of the carbocyanines has been studied. The chromaticity of the dyes has been investigated. [ABSTRACT FROM AUTHOR]

The bromination of 3-allyl-4-hydroxy-2-oxo-1,2-dihydroquinoline by molecular bromine is accompanied by the closure of a five membered furan ring and gives the corresponding 2-bromomethyl-3,9-dihydro-2H-furo[2,3-b]quinolin-4-one. [ABSTRACT FROM AUTHOR]

By analogy with the 4-hydroxy derivatives, the bromination of N-allyl-4-methyl-2-oxo-1,2-dihydroquinoline-3-carboxylic acid leads to the closure of a five membered oxazole ring but, in contrast, it forms the 2-bromomethyl-4-carboxy-5-methyl-1,2-dihydrooxazolo[3,2-a]quinolinium bromide salt. [ABSTRACT FROM AUTHOR]