2-(3-ethyl-2,2-dimethylcyclobutyl-methyl)-4(3H)-quinazolinones

Anthranilic acid and its 5-bromo and 4-chloro derivatives react with pinanoic and pinonoic acid chlorides to give the corresponding N-acyl derivatives. The pinanoyl derivatives give the corresponding 2-(3-ethyl-2,2-dimethyl-cyclobutylmethyl)-4-(3H)-quinazolinones when refluxed in formamide. Pinanoylanthranilic acid reacts with dicyclohexylcarbodiimide to give 2-(3-ethyl-2,2-dimethylcyclobutylmethyl)benz-3,1-oxazin-4(H)-one and subsequently with hydrazine hydrate to give 3-amino-2-(3-ethyl-2,2-dimethylcyclobutylmethyl)-4(3H)-quinazolinone. Refluxing of the pinanoyl- and pinonoylanthranilic acids with acetic anhydride gives acetylanthranilic acid, and pinonoylanthranilic acid gives 4(3H)-quinazolinone with formamide.Riga Technical University, Riga LV-1658, Latvia; e-mail: marina@osi.lanet.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 811–817, June, 1999.     

Acid-catalyzed Conversions of N-(4-Nitrobenzylidene)-2-cyclopropyl- and N-(4-Nitrobenzylidene)-2-alkenylanilines. A new Method for the Synthesis of Dihydroquinolines and Quinolines

The acid-catalyzed conversions of N-(4-nitrobenzylidene)-2-cyclopropyl- and N-(4-nitrobenzylidene)-2-alkenylanilines have been studied. It has been established that the protonated azomethine unit of N-(4-nitrobenzylidene)-2-cyclopropylanilines is not capable of initiating intramolecular heterocyclization with participation of the three-membered ring. Conversion of N-(4-nitrobenzylidene)-2-(1-methylcyclopropyl)aniline to derivatives of quinoline is possible under the influence of concentrated H₂SO₄. Under the same conditions 2-methylcyclopropyl- and cyclopropyl-substituted Schiff's bases form only the corresponding alkenylazomethines (isomerization of the three-membered ring). Under the influence of more moderate acids (trifluoroacetic, polyphosphoric) N-(4-nitrobenzylidene)-2-propenyl- and N-(4-nitrobenzylidene)-2-buten-2-yl)anilines are converted to the corresponding dihydroquinolines and quinolines in high yields. N-(4-Nitrobenzylide! ne)- 2-(2,2-dimethylvinyl)aniline does not form derivatives of quinoline under the influence of the same acids in the given conditions.     

A new and efficient method for the synthesis of 3-(2-nitrophenyl)pyruvic acid derivatives and indoles based on the Reissert reaction

The formation of 3-(2-nitrophenyl)pyruvic acid and its amide and ester derivatives – key compounds for the Reissert indole synthesis – was achieved under various reaction conditions via the acid catalyzed hydrolysis of 5-(2-nitrobenzyliden)-2,2-dimethyl-1,3-oxazolidin-4-one, which is readily available from 3-(2-nitrophenyl)oxirane-2-carboxamide. A new and highly efficient method for the synthesis of indole-2-carboxylic acid derivatives via the intramolecular reductive cyclization of o-nitrophenylpyruvic acid and its amide and ester derivatives was developed using Na₂S₂O₄ in dioxane/water at reflux.     

A simple one-pot synthesis of functionalised 6-(indol-3-yl)-2,2′-bipyridine derivatives via multi-component reaction under neat condition

A series of 4-aryl-6-(1H-indol-3-yl)-2,2-bipyridine-5-carbonitrile derivatives were synthesized via a one-pot multi-component reaction of aromatic aldehydes, 3-(cyanoacetyl)indole and 2-acetyl pyridine in ammonium acetate by conventional heating and microwave irradiation under solvent-free condition. Also a series of 6,6′-di(1H-indol-3-yl)-4,4′-diaryl-2,2′-bipyridine-5,5′-dicarbonitrile derivatives were synthesized using cinnamils, 3-(cyanoacetyl)indole and ammonium acetate. The methodology affords high yields of product at short reaction time.     

Reactions of 3-(4-Aryl-2-thiazolyl)- and 3-(2-Benzothiazolyl)-2-iminocoumarins with N-Nucleophiles

The reaction of 3-(4-aryl-2-thiazolyl)- and 3-(2-benzothiazolyl)-2-iminocoumarins with N-nucleophiles was studied. This reaction gives 2-N-substituted 3-(4-aryl-2-thiazolyl)- and 3-(2-benzothiazolyl)iminocourmarins. N-Nucleophiles such as arylamines, heterocyclic amines, and hydrazine derivatives undergo this reaction.     

Polyfunctional pyrazoles. 4. Synthesis of 3-[3-aryl-1-(2-ethoxycarbonyl)-4-pyrazolyl]acrylic and-propionic acids

3-(3-Aryl-4-formyl-1-pyrazolyl)propionic acids are converted by Knoevenagel condensation under conditions of microwave activation into 3-[3-aryl-1-(2-ethoxycarbonyl)-4-pyrazolyl]acrylic acids. Reduction of the latter with hydrazine hydrate in the presence of Raney nickel gives 3-[3-aryl-1-(2-ethoxycarbonyl)-4-pyrazolyl]propionic acids. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 686–690, May, 2006.     

New Re(I) tricarbonyl-diimine complexes with N,N′-bis(substituted benzaldehyde)-1,2-diiminoethane Schiff base ligands: Synthesis,spectroscopic and electrochemical studies and crystal structures

The syntheses, structures and spectroscopic properties of tricarbonylrhenium(I) complexes with N,N′-bis(2-bromo, 4-bromo, 4-chloro and 3-methoxybenzaldehyde)-1,2-diiminoethane Schiff base ligands have been investigated in this paper. Characterization of these complexes was carried out with FTIR, NMR, UV–Vis spectroscopy, elemental analysis and X-ray crystallography. The electrochemical behavior of the investigated complexes has been studied by cyclic voltammetry. The crystal structures of the 4-chloro, 4-bromo and 4-methoxy substituted complexes are stabilized by intermolecular C–H?Cl and C–H?O hydrogen bonds. The remarkable features of the 2-bromo, 4-bromo and 4-chloro substituted complexes are short intermolecular halogen–oxygen contacts. In the 4-bromo complex, short intermolecular Br?O and O?O contacts link neighboring molecules along the [1 0 0] direction, which are further stabilized by short intermolecular π?π interactions. In 2-bromo complex, intermolecular Br?O interactions link neighboring molecules into 1D extended chains along the [0 1 0] and [0 0 1] directions, forming a 2D network which is parallel to the bc-plane.     

2,2-Bis(3-allyl-4-hydroxyphenyl)hexafluoropropane and fluorosiloxane as coating materials for nerve agent sensors

A simpler technique for the synthesis of 2,2-bis(4-allyoxyphenyl)hexafluoropropane has been achieved from 4,4′-(hexafluoroisopropylidene)diphenol for obtaining 2,2-bis(3-allyl-4-hydroxyphenyl)hexafluoropropane. This monomer and its corresponding hybrid organic/inorganic siloxane polymer are successfully used as a coating material for the detection of toxic chemical warfare agents.     

Darzens synthesis of 2,2-dichloro-3-(2-furyl)-3-hydroxypropionic acid derivatives

Esters and amides of 2,2-dichloro-3-(2-furyl)-3-hydroxypropionic acid were prepared by the reaction of furfural with dichloroacetic acid derivatives under the conditions of the Darzens condensation. The structures of the reaction products were confirmed by their¹H NMR and IR spectra and chemical transformations.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1444–1448, August, 1994.     

Synthesis of 3-(4-chlorophenyl)oxirane-2,2-dicarboxamide

Oxidation of (E)-3-(4-chlorophenyl)-2-cyanoprop-2-enethioamide with hydrogen peroxide or the H₂O₂-KOH system gave 3-(4-chlorophenyl)oxirane-2,2-dicarboxamide. This compound was also obtained by an independent “one pot” synthesis from p-chlorobenzaldehyde and 2-cyanoacetamide through in situ oxidation of their adduct (E)-3-(4-chlorophenyl)-2-cyanoprop-2-eneamide with the H₂O₂-KOH system. The structure of 3-(4-chlorophenyl)oxirane-2,2-dicarboxamide was confirmed by X-ray diffraction and spectroscopic data. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1417–1419, July, 2007.     

N-3-Oxoalkylamides and -Thioamides in the Synthesis of Heterocyclic Compounds. 6. The Effect of Structural Factors on the Regiodirection of Cyclization of Pyridinium Derivatives of N-(3-Oxoalkyl)chloroacetamides. Structure of 1-(4-Hydroxy-4,6,6-trimethyl-2-oxo-3-piperidyl)pyridinium Chloride

The structure of 1-(4-hydroxy-4,6,6-trimethyl-2-oxo-3-piperidyl)pyridinium chloride has been established. Reasons have been found influencing the regiodirection of cyclization of pyridinium derivatives of N-(3-oxoalkyl)chloroacetamides.     

Pd-catalyzed amination of 6-halo-2-cyclopropyl-3-(pyridyl-3-ylmethyl) quinazolin-4(3H)-one

6-Halo-2-cyclopropyl-3-(pyridyl-3-ylmethyl) quinazolin-4(3H)-one derivatives have been synthesized and utilized for amination reactions with aryl, heteroaryl and alkyl amines. Optimization of reaction conditions with different catalysts, ligands, bases, and solvents was conducted. The combination of Pd₂(dba)₃ with DavePhos (L3) proved to be best for these conversions in the presence of NaO^tBu in 1,4-dioxane at 100 °C. The relative reactivities of 6-bromo and 6-chloro-2,3-disubstitued quinazolinones with p-toluidine were conducted and as anticipated the 6-bromo analogue was totally consumed and 6-chloro derivative was completely unreactive.     

Pd-catalyzed synthesis of 3-(diarylmethylene)-2-oxindoles and 3-(arylmethylene)-2-oxindoles

An efficient method for the stereoselective synthesis of 3-(diarylmethylene)-2-oxindoles and 3-(arylmethylene)-2-oxindoles via carbopalladation is described. In this approach, an Ugi-4-component reaction (4-CR) adduct was used as the starting material. A one-pot sequence involving intermolecular carbopalladation C-H activation/C-C bond formation efficiently afforded the oxindole derivatives.     

Facile Synthesis of Unsymmetrical N-Aryl-2, 2-di(1H-indol-3-yl) Acetamide Derivatives

A facile and highly efficient method has been developed for the synthesis of unsymmetrical N-aryl-2,2-di(1H-indol-3-yl)acetamide derivatives by regioselective Friedel-Crafts alkylation of the N-aryl-2-hydroxy-2-(1H-indol-3-yl) acetamide derivatives with various indoles catalyzed by 2 mol/L H₂SO₄ at room temperature in a short reaction time, the yield was up to 94%.     

A new synthesis ofE- andZ(-)(1R,3S)-2,2-dimethyl-3-(3,3,3-trifluoro-2-chloropropen-1-yl)cyclopropanecarboxylic acids from (+)-3-carene

A new synthesis ofE- andZ(-)(1R,3S)-2,2-dimethyl-3-(3,3,3-trifluoro-2-chloropropen1-yl)cyclopropanecarboxylic acids from (+)-3-carene in 21 % total yield was carried out.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 517–518, March, 1995.     

Derivatives of 1-(2-pyridyl)-4,5,6,7-tetrahydroindazole

In reaction of oxidation of 1-(2-pyridyl)3,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydroindazole, the corresponding 4,5-dioxoindazole is obtained, and then 1-(2-pyridyl)-3-methyl-4-carboxy-5-(2-methyl-2-carboxypropyl)pyrazole; in bromination reaction, a series of 5-bromo and 7-bromo derivatives is obtained. From 4,5-dioxoindazole with hydrazides of acids, a series of 4-oxo-5-acylhydrazono derivatives is obtained, and also 1-(2-pyridyl)-3,6,6-trimethyl-4-oxo-5-tosylhydroindazole, which, under the action of caustic, gives the 4-oxo-5-diazo derivative.Riga Technical University, Riga LV-1658. Translated from Khimiya Geterotsiklicheskikh Soerdinenii, No. 3, pp. 351–354, March, 1995. Original article submitted December 29, 1994.     

Rearrangement in the series of 3-(2-aryl-2-oxoethyl)-3,4-dihydroquinoxalin-2(1H)-ones

4-Acetyl- and 4-succinyl-3-(2-aryl-2-oxoethyl)-3,4-dihydroquinoxalin-2(1H)-ones undergo the rearrangement into (Z)-2-(3-arylquinoxalin-2-ylidene)acetic acids accompanied by the elimination of the acyl groups. The nitration of 3-(2-oxo-2-phenylethyl)-3,4-dihydro-quinoxalin-2(1H)-one affords 5-nitro- and 7-nitro-2-carboxymethylidenequinoxalines. The bromination of quinoxalin-2-ones in AcOH gives 3-aryl-2-carboxymethylidenequinoxalines and the corresponding 7-bromo derivatives, with the former products predominating.     

Thermal-Induced Dimerization Cyclization of Ethyl N-(Styrylcarbamoyl)acetates: Formation of 4-Hydroxy-2(1H)-pyridone-3- carboxamide Derivatives

Thermal-induced dimerization cyclization of ethyl N-(styrylcarbamoyl)acetate derivatives has been investigated, leading to 4-hydroxy-2(1H)-pyridone-3-carboxamide derivatives with good yields in diphenyl ether on 200–210 °C. Ethyl N-(styrylcarbamoyl)acetate derivatives readily provided the intermolecular cyclization products 4-hydroxy-2(1H)-pyridone-3-carboxylates on reflux in xylene. In addition, several related 3-acetyl-4-hydroxy-5-phenylpyridin-2(1H)-ones have been prepared. It provided an efficient preparation of 4-hydroxy-2(1H)-pyridone-3-carboxamide derivatives.     

Crystal Structure and Biological Activities of (R)-N''-[2-(4-Methoxy-6-chloro)-pyrimidinyl]-N-[3-methyl-2-(4-chlorophenyl)butyryl]-urea

The title compound (R)-N'-[2-(4-methoxy-6-chloro)-pyrimidyl]-N-[3-methyl-2-(4-chlorophenyl)butyryl]-urea has been synthesized, and its crystal structure and biological behaviors were studied. Crystallographic data: C17H18Cl2N4O3, Mr = 397.25, monoclinic, space group P21/c, a = 12.331 (2), b = 14.025(3), c = 23.085(5) (A), β = 99.607(4)°, Z = 8, V = 3936.2(13) (A)3, Dc = 1.341 g/cm3, F(000) = 1648, R = 0.0718, wR = 0.1585 and μ(MoKα) = 0.353 mm-1. The preliminary biological tests showed that the title compound has definite insecticidal and fungicidal activities.     

Reactions of polyfluorinated thietanes: Selective synthesis of 4-R-2,2-bis(trifluoromethyl)thietane-1-S-oxides and 2-substituted 5-fluoro-4-(trifluoromethyl)-2,3-dihydrothiophenes

Oxidation of 4-substituted 2,2-bis(trifluoromethyl)thietanes by m-chloroperoxybenzoic acid results in selective formation of the corresponding S-oxides in 65-86% yield. Oxidation of 4-C₂H₅S-2,2-bis(trifluoromethyl)thietane under mild conditions led to selective formation of 4-C₂H₅SO₂-2,2-bis(trifluoromethyl)thietane, which under more rigorous conditions was selectively converted into trans-4-C₂H₅SO₂-2,2-bis(trifluoromethyl)thietane-1-S-oxide. Reaction of 4-substituted 2,2-bis(trifluoromethyl)thietanes with activated aluminum powder results in a highly selective ring expansion process, producing the corresponding 5-fluoro-4-(trifluoromethyl)-2,3-dihydro-2-alkoxythiophenes in 58-93% yield. These compounds were also prepared in 61-85% yield using a “one-pot” procedure, starting from sulfur, hexafluoropropene and the corresponding vinyl ether without isolation of any intermediates. Both 2-i-C₃H₇O- and 2-t-C₄H₉O- 5-fluoro-4-(trifluoromethyl)-2,3-dihydrothiophenes were converted into 2-fluoro-3-trifluormethylthiophene by reaction with P₂O₅.