Condensation of salts of 2-amino-1,3,4-thiadiazoles with β-chlorovinyl ketones, β-chlorovinyl aldehydes,and 1,1,3,3-te traethoxypropane

The condensation of 2-amino-1,3,4-thiadiazole perchlorates with -chlorovinyl ketones, -chlorovinyl aldehydes, and 1,1,3,3-tetraethoxypropane has given 1,3,4-thiadiazolo [3,2-a]pyrimidinium salts. The structure of the reaction products and the ratio of the isomers formed has been established by PMR spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1285–1288,September, 1973.     

Common and Specific Features of the Michael Condensation in the Series of 3-R-3H-Furan-2-ones

The Michael condensation in the series of 5-aryl-3H-furan-2-ones with chalcones containing electron-donating substituents was studied. In the case of ,-unsaturated ketones containing an electrondonating substituent, the reaction does not stop at the stage of formation of 1,5-dicarbonyl compounds but is accompanied by intramolecular cyclodehydration yielding a new series of furo[2,3-b]-4H-pyrans. A mechanism of formation of these products was suggested. The structure of reaction products was proved by IR and ¹H NMR spectroscopy.     

Investigation of the colour reaction of phenols with MBTH,II: Properties of the isolated products of the reaction with phenol, 2,6-dimethylphenol and 4-methylphenol

The following model compounds for the study of the oxidative coupling reactions of 2-hydrazono-3-methylbenzothiazoline (MBTH) with phenolic compounds were prepared: thep-coupling products of the reagent with phenol and 2,6-xylenol and theo-coupling product withp-cresol. The proposed structure of the dyes was confirmed. In strongly polar and ionic media the azobetaine form of the products predominates, and in non-polar media the azine structure. The principal physico-chemical properties of the products were determined and the results contributed to formulation of the course of the coupling reaction, and to optimization of the conditions for determination of small amounts of phenolic substances. The violeto-coupling product is less stable than the redp-coupling products, and intramolecularly hydrogen-bonded six-membered ring is assumed to exist in the structure. In acid medium the dyes are mainly monoprotonated, and partly diprotonated in concentrated sulphuric acid medium. The products are stable up to about pH 11. These properties make extraction into low-polarity solvents possible. The dye derived from 2,6-xylenol andp-cresol has not hitherto been prepared. The principal spectral characteristics, _max(), of the products in ethanol medium are: 499 nm (4.7 × 10⁴ 1·mole^–1 cm^–1) for the phenol derivative, 486 nm (5.0 × 10⁴) for the 2,6-xylenol product, and _max 540 nm for thep-cresol product.Part I: Mikrochim. Acta [Wien]1977,I, 241     

The Reaction of Benzoylacrylic Acid with ortho-Phenylenediamines

The reaction of -benzoylacrylic acid with substituted o-phenylenediamines gives substituted quinoxal-2-ones. The structure of one of the products has been proved using X-ray analysis.     

Prototropic tautomerism and absorption spectra of substituted 4-hydroxyhexahydropyrimidinethiones-2

The IR and UV absorption spectra of the products of reaction of certain -isothiocyanoketones with ammonia, primary, and secondary amines are studied. It is shown that ammonia and primary amines usually give substituted 4-hydroxyhexahydropyrimidinethiones-2, which in the solid state are involved in intermolecular association due to hydrogen bonding. Solutions of these compounds exhibit ring-chain tautomerism equilibrium between a cyclic hydroxy form and an acyclic oxo form related to the class of oxoalkylthioureas. The reaction products both from -isothiocyanoketones and secondary amines, are substituted thioureas, both in the crystalline state and in solution. All the substances studied have a thione structure.     

Thermal decomposition products of poly(vinyl alcohol)

The thermal decomposition of poly(vinyl alcohol) is known to occur in two stages. In a study of first-stage decomposition, this polymer was pyrolyzed in vacuum at 240°C for 4 hr and the products were determined by using gas chromatography. The main products were water, aldehydes having the general formula and methyl ketones having the formula , where n = 0, 1, 2, 3, etc. Mechanisms for the formation of these carbonyl compounds are discussed.     

Synthesis and NMR analysis of spiranic heterocycles from carbohydrate derivatives

We report the synthesis of some furanose and pyranose acylhydrazones and their heterocyclization products. The new compounds were characterized physically and spectroscopically and the syn‐anti and (R)‐(S) configuration was determined by NOESY experiments. We discuss the influence of the nucleophile, the temperature and the precursor structure on the heterocyclization products.     

Addition of organic and inorganic moieties to Fe2(CO)6(μ-EE′) and Fe3(CO)9(μ3-E)(μ3-E′) [E=Se,Te;E′=S,Se, Te]

Reaction of the iron chalcogen carbonyl clusters Fe₂(CO)₆(-EE) and Fe₃(CO)₉(₃-E)(₃-E), [E=Se, Te;E=S, Se, Te] with various inorganic and organic moieties produce a number of higher nuclearity clusters. The reactivity pattern of these iron chalcogen carbonyl compounds and the structure of the products formed are discussed.     

Reasons for the formation of pyrazolines of anomalous structure from unsaturated aldehydes

It is shown by gas-liquid chromatography and PMR spectroscopy that the reaction of alkylhydrazines with -alkylacroleins, as distinct from the -alkyl derivatives, results only in the formation of the normal products (1,4-dialkyl-²-pyrazolines or the corresponding -alkylacrolein alkylhydrazones). The latter isomerize on moderate heating with a catalytic amount of hydrochloric acid, the terminal C=C bond migrating to the middle of the chain to give , -dialkylacrolein or trialkylacrolein hydrazones rather than the expected cyclization products, 1, 4-dialkyl-²-pyrazolines. Condensation of isopropylhydrazine with -methyl--ethylacrolein and cyclization of -methyl--ethylacrolein isopropylhydrazone under forcing conditions gave the pyrazoline of anomalous structure, 1-isopropyl-3-ethyl 4-methyl-²-pyrazoline, without any of the expected 1-isopropyl-4-methyl-5-ethyl-²pyrazoline. The opinion is expressed that the formation of the pyrazoline with the anomalous structure is due to addition of the NH group of the hydrazine to the carbonyl group of the unsaturated aldehyde, which is sterically more accessible to the NH group than is the -substituted C=C bond.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1249–1254, September, 1970.     

Synthesis and structures of substituted 5,6-dihydro-spiro(benz[4,5]imidazo[1,2-<Emphasis Type="Italic">c</Emphasis>]quinazoline-6,3′-indolin)-2′-ones

The reactions of 2-(2-aminophenyl)benzimidazole with substituted isatins afforded the corresponding 5,6-dihydrospiro(benz[4,5]imidazo[1,2-c]quinazoline-6,3indolin)-2-ones. The spirocyclic structure of the reaction products was established by NMR spectroscopy and X ray diffraction analysis.Results of the study were presented at the International Conference Modern Trends in Organoelement and Polymer Chemistry dedicated to the 50th anniversary of the A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences (May 30–June 4, 2004, Moscow).Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1987–1989, September, 2004.     

New one‐ pot synthesis of pyrazolo[3,4‐c]pyridazine and isoxazolo‐[5,4‐b]pyridine derivatives from potassium cyanoacetahydroxamate

The reaction of potassium cyanoacetohydroxamate 1 with ethyl 2‐aryl‐hydrazono‐3‐oxobutyrates 2 gave the unexpected pyrazolo[3,4‐c]pyridazines 7 and isoxazolo[5,4‐b]pyridines 10 via a one‐pot reaction. A mechanistic proof is suggested to account for the products.     

Reaction of 2-mercaptopyrimidines with some α,ω-dihaloalkanes

Conclusions In the reaction of some 2-mercapto-4,6-disubstituted pyrimidines with different,-dihaloalkanes, thiazolepyrimidine and pyrimidothiazine salts, 2-(-haloalkylthio)-4,6-disubstituted pyrimidines, and,-bis (4,6-disubstituted pyrimidinyl-2-thio) alkanes are formed. The structure of the products of the reactions is a function of the nature of the substituents in the pyrimidine ring, the number of methylene groups in the,-dihaloalkanes, and the ratio of the reagents.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1396–1402, June, 1984.     

Crystallisation of zeolite mordenite and ZSM-5 without the aid of a template

A complex of tenoxicam with-cyclodextrin was prepared by using co-grinding and freeze drying methods. The resulting products were studied by the solubility method, ultraviolet and infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry. The dissolution behaviour of the products was also examined. The dissolution rate of the co-ground and freeze-dried products was faster than that of the pure drug and the physical mixture of drug and-cyclodextrin. The enhanced dissolution rate of the products might be attributed to the amorphous state, the increased wettability of the drug and the inclusion complex formation.     

Structure and properties of anthranilato- andN-phenylanthranilatorhodium(I) complexes withcis,cis-cycloocta-1,5-diene

Summary Reaction products of [{RhCl(-COD)}₂] (COD=cycloocta-1,5-diene) with sodium salts of anthranilic andN-phenylanthranilic acid have been isolated and their structures and catalytic activities investigated. A monomeric square-planar structure with O-Rh-N bonds is postulated for the anthranilate complex, and a dimeric structure, with carboxylate bridges and without binding of the -amine nitrogen to rhodium, is postulated for theN-phenylanthranilate. Catalytic activities in hydrogenation of some alkenes, dienes, aromatic and heteroaromatic compounds have been investigated at ambient temperature and pressure. The stability of the complexes under hydrogenation conditions is low and complete saturation has been achieved only forn-alkenes and dienes.     

Substituted 1,2-Thiazetidine 1,1-Dioxides. Synthesis and Properties of N-Alkylated and N-Acylated Derivatives of 1,2-Thiazetidine-3-acetic Acid 1,1-Dioxide

Summary. 1,2-Thiazetidine-3-acetic acid 1,1-dioxide was N-alkylated using bromoacetates, and N-acylated using either acyl chlorides, protected amino acid fluorides, or N-protected amino acid NCA, which seemed to be the most universal method. Most of the obtained -sultam peptides were sensitive against humidity, they hydrolyzed forming sulfonic acids, and reactions with amines resulted in sulfonamides. Reactions of N-acylated products showed that the sulfonyl group was faster attacked than the imide structure.     

Alkali promoted rare earth metal phosphates for vapour phase O-alkylation of α- and β-naphthols with methanol

The vapor-phase catalytic O-alkylation of - and -naphthols with methanol has been investigated over lanthanum, cerium, samarium, and antimony phosphate catalysts promoted with cesium hydroxide. Among various catalysts investigated, the Cs-SmPO₄ combination catalyst provided better catalytic activity and selectivity. The CsOH promoter suppressed formation of C-alkylated side products and enhanced the O-alkylation selectivity. Characterization of these catalysts by X-ray diffraction and FT-infrared techniques revealed that the cesium promoter has no influence on the bulk structure of the catalysts. Temperature programmed desorption of anhydrous ammonia over promoted and unpromoted catalysts revealed that the cesium promoter decreases total surface acidity of the catalysts.     

The chemistry of ethyleneimine

The reaction of N-aminoethyleneimine (I) with substituted benzenesulfonyl chlorides (II) has been studied. The main products of the heterolysis of the ring are substituted N-(-chloroethyl)benzenesulfonohydrazides (V). The structure of V has been shown by IR, UV, and PMR spectroscopy, and also by independent synthesis.For part III, see [23].     

Five-membered 2,3-dioxo heterocycles: XLIX. Reaction of methyl 1-aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrrole-2-carboxylates with N-substituted 3-amino-5,5-dimethyl-2-cyclohexenones

Methyl 1-aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates react with N-substituted 3-amino-5,5-dimethyl-2-cyclohexenones to give 4-hydroxy-1-aryl-3-aroyl-6,6-dimethyl-1, 2,3,4,5,5,6,7-octahydro-1H,2H-indole-3-spiro-2-pyrrole-2,4,5-triones. The structure of the products was proved by the X-ray diffraction data for the 1-cyclohexyl derivative.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 12, 2004, pp. 1840–1845.Original Russian Text Copyright © 2004 by Bannikova, Maslivets, Aliev.For communication XLVIII, see [1].     

Asymmetric halogenation and hydrohalogenation of ethyltrans-cinnamate in crystalline cyclodextrin complexes

The gas-solid halogenation and hydrohalogenation using microcrystalline cyclodextrin complexes are found to be efficient for production of the optical active halides of ethyltrans-cinnamate in moderate optical yields: On exposure to HBr at 20°C for 15–20 hr, the cinnamate in solid - and -cyclodextrin complexes yields ethyl R-(+)-3-bromo-3-phenylpropanoate in 46% e.e., and S-(–)-enantiomer in 31% e.e., respectively. No addition nor substitution products are obtained with HC1 vapor at 0–50°C for 15–65 hr. Bromination of the -cyclodextrin complex results in the formation of optical active ethylerythro-2,3-dibromo-3-phenylpropanoate, while chlorination gives the optical active mixture oftrans andcis addition products, ethylerythro- andthreo-2,3-dichloro-3-phenylpropanoates in 60–80% yields. Mechanism of chiral induction in the present gas-solid reaction has been proposed on the basis of the crystal structure of the complex.