Some products of the coupling of gossypol with diazotized amines

Summary A series of products of the coupling of gossypol with diazotized amines has been obtained. It has been established that they are monoadducts. The possibility of using them as dyes for cotton fabric has been shown.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 607–609, September–October, 1976.     

An HMO study of the azo-hydrazone tautomerism in diazonium coupling products of 5-isoxazolones

The HMO method has been used to study tautomerism in 3-substituted 4-arylazo-5-isoxazolones ( 2 ), the possible tautomeric structures being 2a-2d. Also the common anions of these tautomers, 6 , have been theoretically studied. In addition to the free molecules, HMO calculations have been carried out for structures with hydrogen bonds to protic solvents, for tautomers with intramolecular hydrogen bonds, and for dimers formed via intermolecular hydrogen bonds. In all these situations, the hydrazone form 2a has been shown to be most stable. Also the inductive effect of electron-donating and electron-withdrawing substituents in the arylazo moiety upon the stability of various tautomers has been investigated. The results obtained on the basis of HMO calculations are in full agreement with the experimental data of Summers and co-workers. Several m- and p-substituted 4-arylazo-3-methyl-5-isoxazolones have been synthesized and their spectral data and melting points reported.     

Reaction of 4-cyano-5-aminopyrazole and 3,4-dicyano-5-aminopyrazole with dimethylformamide diethylacetal

The condensation of 4-cyano-5-aminopyrazole or 3,4-dicyano-5-aminopyrazole with dimethylformamide diethylacetal was studied. It was shown that, in addition to the formation of dimethylaminomethyleneamino derivatives, alkylation of the pyrazole ring occurs under severe conditions without a solvent. Only the corresponding formamidino derivatives are formed when the same reactions are carried out in methanal under milder conditions. The site of addition of an ethyl group to the pyrazole ring in the N-alkyl derivatives obtained was established by ¹³C NMR and PMR spectroscopy. The possibility of the synthesis of 4-amino- or 4-methylmercaptopyrazolo[3,4-d]pyrimidines by cyclization of the corresponding dimethylamino- methyleneaminopyrazoles with a cyano group in the ortho position was demonstrated for the first time.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 259–264, February, 1984.     

Reaction of 3-hetero-substituted 2-phenyl-4-thioxo-3,4-dihydro-quinazolines with acyl chlorides and phenacyl bromides

Some 2, 5-disubstituted 1, 3, 4-thiadiazoles 5 were obtained by reaction of 3-amino-2-phenyl-4-thioxo-3, 4-dihydroquinazoline ( 1 ) with acyl chlorides. Reaction of 3-hydroxy-2-phenyl-3, 4-dihydroquinazoline ( 3 ) with phenacyl bromides was carried out either in dry acetonitrile or dimethylformamide to give 2-phenyl-4-phenacylthio-3-quinazolinium N-oxides 7 or 2-phenyl-4-phenacylidene-1H-3-quinazolinium N-oxides' 8 , respectively.     

The structure of 1-phenyl-3-benzoylamino-4-benzoylpyrazol-2-in-5-one

Crystal and molecular structure of 1-phenyl-3-benzoylamino-4-benzoylpyrazol-2-in-5-one as a product of the benzoylation of 1-phenyl-3-benzoylaminopyrazol-2-in-5-one was characterised by X-ray single crystal diffraction. It is shown that 1-phenyl-3-benzoylamino-4-benzoylpyrazol-2-in-5-one exists in the solid phase in an NH-tautomeric form, which is stabilised by two intramolecular hydrogen bonds and one intermolecular bond with the solvate dioxane molecule, the latter being used as a solvent for recrystallisation.     

Waste-free chemistry of diazonium salts and benign separation of coupling products in solid salt reactions

Gas-solid and solid-solid techniques allow for waste-free and quantitative syntheses in the chemistry of diazonium salts. Five techniques for diazotations with the reactive gases NO(2), NO and NOCl are studied. Two types are mechanistically investigated with atomic force microscopy (AFM) and are interpreted on the basis of known crystal packings. The same principles apply to the cascade reactions that had been derived from one-step reactions. Solid diazonium salts couple quantitatively with solid diphenylamine and anilines to give the triazenes. Azo couplings are achieved with quantitative yields by cautious co-grinding of solid diazonium salts with beta-naphthol and C-H acidic heterocycles, such as barbituric acids or pyrazolinones. Solid diazonium salts may be more easily applied in a stoichiometric ratio for couplings in solution. Co-grinding of solid diazonium salts with KI gives quantitative yields of various solid aryl iodides. The unavoidable coupling products in salt reactions are completely separated from the insoluble products in a highly benign manner. The solid-state reactions compare favourably with similar solution reactions that produce much waste. The structures of the products are elucidated with IR and NMR spectroscopy and mass spectrometry, while the tautomeric properties of the compounds are studied with density functional calculations at the B3LYP/6-31G* and BLYP/6-31G** levels.     

Reaction of 3-azido-5-phenyl-1,2,4-oxadiazole with dimethylformamide,a new deoxygenative coupling reaction

When 3-bromo-5-phenyl-1,2,4-oxadiazole (1b) is heated with sodium azide in anhydrous dimethylformamide at 130°, 3-dimethylamino-($\text{1c}$) and 3-dimethylaminomethyleneamino-5-phenyl-1,2,4-oxadiazole ($\text{1d}$) are formed, the latter by a new deoxygenative coupling of the azide ($\text{1a}$), or the nitrene derived from it, with the solvent.     

Aminopyrazoles and their conjugated acids. An X-ray study of 3,5-dimethyl-4-aminopyrazole and the Picrate of 3(5)-aminopyrazole

The crystal structure determination of 3,5-dimethyl-4-aminopyrazole ( 3 ) and of 3(5)-aminopyrazolium picrate salt ( 5a ) have been undertaken. The packing in 3 is characterized by the formation of sheets in which the N-H of the pyrazole and one H atom of the amino group are involved. The remaining HB donor interconnects sheets. In 5a , the anions and the cations are linked by a two-dimensional network of hydrogen bonds in the ab plane. Each N-H and C-H in the cation are involved in hydrogen interactions with the O atoms of the anion. Ab initio molecular orbital methods at the HF and B3LYP levels using a 6–31G** basis set have been carried out to compare the relative stability of the tautomeric forms of the 3(5)-aminopyrazolium and 4-aminopyrazolium cations.     

PMP的酰化反应及其产物萃取性能的研究

合成了9个新1-苯基-3-甲基-5-吡唑酮(PMP)的烷氧基苯酰基衍生物.PMP在不同条件下的酰化研究表明酰氯的量和碱的性质和量对反应方向有很大影响.并用5个C-烷氧基苯酰基PMP衍生物做了萃取La(III)和Y(III)离子的试验,发现1-苯基-3-甲基-4-(3,4,5-三甲氧基)苯甲酰基-4-吡唑酮的萃取性能优于PMBP.     

Crystal structure of copper sulfate and thiocyanate complexes with 5-bromo-and 5-nitrosalicylaldehyde thiosemicarbazones

The crystal structures of (5-bromosalicylidenethiosemicarbazido)aquacopper(II) sulfato(5-bromosalicylidenethiosemicarbazido)aquacuprate(II) tetrahydrate (I), (5-nitrosalicylidenethiosemicarbazido)dimethylsulfoxide(methanol)copper(II) sulfate (II), and catena(μ-thiocyanato)(5-nitrosalicylidenethiosemicarbazido)copper(II) (III) were determined. In structure I, the independent part of the unit cell contains four water molecules of crystallization and the cation-anion complex [Cu(H₂O)(L)][Cu(H₂O)(L)(SO₄)] containing two nonequivalent copper complexes (A and B). In these, the metal atom coordinates monodeprotonated 5-bromosalicylaldehyde thiosemicarbazone (HL) and water molecules, and in anion B also a sulfate ion. In complex ions A and B, sulfur, azomethine nitrogen, and phenolic oxygen of the salicylidene thiosemicarbazone fragment, and also water molecule form a distorted planar square around the metal atom. The axial vertex of the pyramid in anion B is occupied by the oxygen atom of the monodentate sulfate anion. In structure II, the independent part of the unit cell contains the (5-nitrosalicylidenethiosemicarbazido)dimethylsulfoxide(methanol)copper(II) complex cation and the sulfate anion. The coordination polyhedron of the central atom is a slightly distorted tetragonal pyramid whose base is formed by sulfur, azomethine nitrogen, phenolic oxygen of thiosemicarbazone, and dimethyl sulfoxide oxygen. The axial position is occupied by the methanol oxygen atom. In structure III, the copper atom coordinates 5-nitrosalicylaldehyde thiosemicarbazone and the thiocyanate ion, which combines complexes into infinite polymer chains along the [010] direction. The copper coordination polyhedron in III is a slightly distorted tetragonal pyramid whose base is formed by sulfur, azomethine nitrogen, phenolic oxygen of thiosemicarbazone, and nitrogen of thiocyanate ion, the axial vertex is occupied by sulfur of thiocyanate ion of the neighboring complex.     

Reaction of 5-aminopyrazole derivatives with ethoxymethylene-malononitrile and its analogues

A one-pot synthesis using 5-aminopyrazole derivatives 1 with ethoxymethylenemalononitrile (EMMN), ethyl ethoxymethylenecyanoacetate (EMCA) or diethyl ethoxymethylenemalonate (DEMM) gave pyrazolo-[1,5-a]pyrimidine compounds 2,4,8 . Also, the one step reaction of EMCA with hydrazine hydrate afforded ethyl(4-ethoxycarbonyl-5-pyrazolyl)aminomethylenecyanoacetate 3c . On the other hand, the reaction of 1-substituted 5-aminopyrazole-4-carboxamide 9 with EMMN afforded pyrazolo[3,4-d]pyrimidine compounds 10 .     

Formylation of 2-phenyl- and 3-phenyl-5-hydroxybenzofuran derivatives

The Vilsmeier formylation of 2-phenyl- and 3-phenyl-5-hydroxybenzofuran derivatives was studied. It is shown that 2-phenyl-5-methoxybenzofuran is formylated in the 4 position, whereas 3-phenyl-5-methoxybenzofuran is formylated in the 2 position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1023–1024, August, 1976.     

An investigation of the structure of the nitration products of 1-phenyl-5-styryltetrazole using the mass-spectrometric method

Depending on the reaction conditions, the nitration of 1-phenyl-5-styryltetrazole (I) with nitric acid and nitrating mixture give 1-(4-nitrophenyl)-5-styryltetrazole, 1-(4-nitrophenyl)-5-(4-nitrostyryltetrazole), and 1-(2,4-dinitrophenyl)-5-(4-nitrostyryl) tetrazole. The structures of the compounds obtained have been established by an analysis of their mass spectra and of the mass spectra of model compounds. The positions and sequences of entry of the nitro groups have been determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 558–563, April, 1980.     

Reaction of 3-nitro- and 3-diethylphosphonocoumarin with phenacyl bromide. X-ray molecular structure of 3-nitro-3,4-phenacylidenecoumarin

3-Nitro- and 3-diethylphosphonocoumarins 4a,b react with phenacyl bromide stereoselectively under phase-transfer conditions, in the presence of a base and of a transfer agent, to give the cyclopropyl derivatives 6 and 7 in good yields. A mechanistic explanation is given for the stereoselectivity of the reaction. The X-ray molecular structure of compound 6a is also presented.