Reaction of 5-Aryloxytetrazoles with Dimethyl Sulfoxide and DMSO-Acetic Anhydride. Structure and Quantum-Chemical Calculations of 1-Methylsulfanylmethyl-5-(4-nitrophenoxy)tetrazole

Decomposition of methyl 5-(4-nitrophenoxy)tetrazole-2-carboxylate in dimethyl sulfoxide at room temperature yields a mixture of 1-methylsulfanylmethyl-5-(4-nitrophenoxy)tetrazole, 1- and 2-methyl-5-(4-nitrophenoxy)tetrazoles, and 5-(4-nitrophenoxy)tetrazole. Methyl 5-aryloxytetrazole-2-carboxylates containing electron-donor substituents in the aryloxy group do not give rise to the corresponding products under analogous conditions. The reactions of 5-aryloxytetrazoles [Ar = 4-O₂NC₆H₄, C₆H₅, 2,6-(MeO)₂C₆H₃] with dimethyl sulfoxide in the presence of acetic anhydride lead to mixtures of 1- and 2-methylsulfanylmethyl-5-aryloxytetrazoles whose yield and ratio depend on the substituent in the aryloxy group. The structure of 1-methylsulfanylmethyl-5-(4-nitrophenoxy)tetrazole was studied by X-ray analysis, two-dimensional NMR spectroscopy (HSQC, HMBC, NOESY), and quantum-chemical methods (ab initio, AM1, PM3). A highly selective procedure was developed for the synthesis of 5-(4-nitrophenoxy)tetrazole.__________From Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 1076–1084.Original English Text Copyright © 2005 by Dabbagh, Noroozi Pesyan, Bagheri, Takemo, Hayashi.The original article was submitted in English.     

Tetrazoles. 42. 2-(4-Nitrophenyl)-5-functionally-substituted Tetrazoles

We have studied the reactions of 5-methylsulfonyl-2-(4-nitrophenyl)tetrazole with N- and O-nucleophiles. For the first time we show that in 2-(4-nitrophenyl)-5-phenoxytetrazole, the tetrazole ring is substituted when treated with phenoxide ion, 4-nitrodiphenyl ether being formed.     

Synthesis and structures of 5-(pyridyl)tetrazole complexes of Mn(II)

New Mn(II) complexes containing 5-(2-pyridyl)tetrazole, 5-(3-cyano-4-pyridyl)tetrazole or 5-(4-pyridyl)tetrazole ligands are described. The complexes are prepared by reaction of the corresponding cyanopyridines with sodium azide in the presence of Mn(II) salts. All the complexes have been characterized by X-ray crystallography, which reveals that 5-(pyridyl)tetrazole ligands can coordinate to Mn through either type of nitrogen atom in the tetrazole residue or via the pyridyl group. In the solid state, extended 2D and 3D structures are produced through networks of hydrogen bonding (involving water molecules and the tetrazolate residue). Acidification of the complexes produces the corresponding free 5-(pyridyl)-1H-tetrazole.     

3-(2-Quinolyl)- and 3-(5-carbethoxyfuryl-2)coumarins

3-(2-Quinolyl)- and 3-(5-carbethoxyfuryl-2)coumarins were prepared by reaction of substituted salicylaldehydes and hetarylacetonitriles. Alkylation and acylation of 3-hetaryl-7-hydroxycoumarins were studied. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 432–434, September–October, 2005.     

3-Alkyl-2-[3(4)-pyridyl]-5-(2-vinyloxyethoxymethyl)-oxazolidines

1-Alkylamino-3-(2-vinyloxyethoxy)-2-propanols react with 3-and 4-pyridinecarbaldehydes to give equimolar mixtures of cis- and trans-3-alkyl-5-(2-vinyloxyethoxymethyl)-2-[3(4)-pyridyl]oxazolidines.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 104–108.Original Russian Text Copyright © 2005 by Kukharev, Stankevich, Lobanova, Klimenko, Kukhareva.     

5-Phenyl-2-(pyrazol-4-yl)-1,3,4-thiadiazoles

By recyclization of 2-R-6-ethyl-7-hydroxy(methoxy)-3-(5-phenyl-1,3,4-thiadiazol-2-yl)chromones when treated with hydrazine hydrate and phenylhydrazine, we synthesized 5-phenyl-2-(3-R-5-R1-1H-pyrazol-4-yl)-1H-1,3,4-thiadiazoles and 2-(3-R-5-R1-1-phenyl-1H-pyrazol-4-yl)-5-phenyl-1H-1,3,4-thiadiazoles. We confirmed the structure of the latter from ¹H NMR spectra.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 781–787, May, 2005.     

Synthesis of 2-Functionalized 4-(Diethoxyphosphorylmethyl)-5-(1-bromoalkyl)furans and Their Reactions with Amines

Phosphorylation of esters and nitriles of 4-chloromethyl-5-alkylfuran-2-carboxylic acids with triethyl phosphite yields the corresponding phosphonates. These compounds are brominated with N-bromosuccinimide in carbon tetrachloride at the α-position of the alkyl radical. The resulting 2-(1-bromoethyl)-, 2-(1-bromopropyl)-, and 2-(1-bromoisobutyl)furans react with secondary amines following the scheme of nucleophilic substitution. The dehydrobromination product was isolated only in the reaction of ethyl 4-(diethoxyphosphorylmethyl)-5-(1-bromoisopropyl)furan-2-carboxylate with triethylamine, but its yield was low. The reactions of bromo phosphonates with lithium carbonate in DMF result in their decomposition.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 820–828.Original Russian Text Copyright © 2005 by Pevzner.     

Synthesis of 5-Amino-4-(4-aryl-2-thiazolyl)-2,3-Dihydro-2-Pyrrolones

A method was developed for preparation of 5-amino-4-(4-aryl-2-thiazolyl)-2,3-dihydro-2-pyrrolones by alkylation of 4-aryl-2-thiazolylacetonitriles by N-substituted chloroacetamides in the presence of K₂CO₃. In 1-(1-naphthyl)-substituted pyrrolones atropoisomerism was observed.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 2, 2005, pp. 266–269.Original Russian Text Copyright © 2005 by Resnyanskaya, Tverdokhlebov, Tolmachev, Volovenko.     

Selective N(2) alkylation of tetrazole and 5-substituted tetrazoles by alcohols

Alkylation of tetrazole and its 5-substituted derivatives by 5-tert-butyl, isopropyl, and cyclohexyl alcohols in concentrated H₂SO₄ results in high yields of the corresponding 2-alkyltetrazoles alone, irrespective of electronic properties and size of the substituent at the 5-position of the tetrazole ring. The tert-butylation of tetrazole in phosphoric acid results in the formation of a mixture of isomeric 1- and 2-substituted derivatives, the concentration of the 1-isomer increasing with decrease in the concentration of the acid in the mixture.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1643–1647, December, 1990.     

Thymidine- and AZT-linked 5-(1,3-dioxoalkyl)tetrazoles and 4-(1,3-dioxoalkyl)-1,2,3-triazoles

N3 of thymidine and of 3′-azido-3′-deoxythymidine (AZT) has been linked to a tetrazole ring by condensation of nucleoside-derived 2-oxonitriles with the lithium salt of 5-acetyl-1-(4-fluorobenzyl)tetrazole (obtained by a ‘click’ reaction). 4-Acetyl-1,2,3-triazole, also prepared by a Cu-catalysed cycloaddition, has been similarly linked. A route for the conjugation of NRTIs with pharmacophoric elements of integrase inhibitors (INIs) has thus been disclosed.     

Synthesis and hybridization properties of 2′-O-(tetrazol-5-yl)ethyl-modified oligonucleotides

2′-O-(1H-Tetrazol-5-yl)ethyladenosine was synthesized using 2′-O-cyanoethyladenosine derivative as a key intermediate. The 2′-O-(1H-tetrazol-5-yl)ethyl modifications exhibited intriguing properties such as the change in the structure of the tetrazole residue between a protonated and a deprotonated form. The T_m experiments of various oligodeoxynucleotides having a 2′-O-(1H-tetrazol-5-yl)ethyl-modified adenosine showed reduced hybridization affinity in comparison to the unmodified oligonucleotides toward their complementary oligodeoxynucleotides. The mechanism of the reduced hybridization affinity was discussed on the basis of the structure and the physicochemical properties of the tetrazole moiety.     

Stereoselective synthesis of dinucleoside phosphate aryl esters by using new condensing reagents,arenesulfonyl 5-(pyridin-2-yl)-tetrazole1

Deoxyadenylyl-(3'-5')-phosphoro-o-chlorophenyl deoxyadenosine having the Sp configuration was synthesised stereoselectively by condensing N,5'-bis-dimethoxytrityldeoxyadenosine 3'-(o-chlorophenyl) phosphate with N,3'-bis-dimethoxytrityldeoxyadenosine using 1-2,4,6-triisopropylbenzene-5-(pyridin-2-yl) tetrazole as the activating reagent followed by dedimethoxytritylation. The absolute configuration of this diastereomer was determined spectroscopically by comparison of two corresponding diastereomers which were prepared by using a conventional condensing reagent and isolated by chromatography on silica gel. Their nuclear Overhauser effect in proton magnetic resonances and the circular dichroism of these two diastereoisomers could only be explained if the product obtained by the stereoselective synthesis had Sp configuration. Our results also suggest that phosphotriesters of this type exist in solution as an equilibrium of folded and extended forms.     

Energetic salts of azotetrazolate, iminobis(5-tetrazolate) and 5, 5'-bis(tetrazolate)

Energetic ionic salts of azotetrazolate (AT), iminobis(5-tetrazolate) (IBT) and 5, 5'-bis(tetrazole) (BT) were synthesized; 1-methyl-4-aminotriazolium azotetrazolate has a layered structure and exhibits a heat of formation of +4360 kJ kg(-1).     

Synthesis of 2-(1,2,3-Thiadiazol-5-yl)-1H-benzimidazoles

We have developed a convenient preparative method for synthesis of previously unknown 2-(1,2,3-thiadiazol-5-yl)-1H-benzimidazoles based on reaction of benzoylhydrazones of 2-acylmethyl-1H-benzimidazoles with thionyl chloride. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1391–1393, September, 2005.     

1-(5-氯甲基-2-羟基-4-烷氧基)苯乙酮的合成

以2,4-二羟基苯乙酮为起始原料,经羟基烷基化和氯甲基化反应合成了3个新型查尔酮类衍生物的关键中间体——1-(5-氯甲基-2-羟基-4-烷氧基)苯乙酮,其结构经1H NMR和ESI-MS确证。     

Gelation of La(III) cations promoted by 5-(2-pyridyl)tetrazolate and water

Addition of water to the product formed when LaCl3 and 1H-5-(2-pyridyl)tetrazole (LH) were treated with an excess of triethylamine in ethanol, resulted in the reversible formation of a hydrogel, which when further treated with EtOH-iPrOH produced crystals of [LaL3(H2O)3].(H2O)4, as determined by X-ray crystallography.     

Synthesis and properties of 1-(2-hydroxyethyl)tetrazole

The heterocyclization of monoethanolamine with ethyl orthoformate and sodium azide in acetic acid was studied. It was shown that the reaction proceeds through a step involving the formation of a disubstituted formamidine and leads to the production of 1-(2-hydroxyethyl)tetrazole in high yield. A method for the purification of 1-(2-hydroxyethyl)tetrazole by complexing with cupric chloride was developed, and its physicochemical properties and some chemical transformations were investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1422–1424, October, 1985.     

Ring-chain tautomeric transformations of the product of diazotization of 5-(2′-aminophenyl)tetrazole

It was established on the basis of IR spectral data that the products of the reaction of 5-(2-aminophenyl)tetrazole and 4-hydrazinobenzo-1,2,3-triazine with amyl nitrite have the 5-(2-diazoniaphenyl)tetrazolestructure in the crystalline state. A study of the UV spectra of the latter showed that in methanol solution it exists in equilibrium with the isomeric 4-azidobenzo-1,2,3-triazine.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1557–1559, November, 1981.     

Synthesis of 3-(3″-Aminobenzoylamido)-1-(2′,4′,6′-trichlorophenyl)pyrazol-5-one,an Intermediate in the Synthesis of the Purple Component of Color Photographic Materials

Catalytic reduction of 3-(3″-nitrobenzoylamido)-1-(2′,4′,6′-trichlorophenyl)pyrazol-5-one with hydrogen and hydrazine hydrate to 3-(3″-aminobenzoylamido)-1-(2′,4′,6′-trichlorophenyl)pyrazol-5-one, the key intermediate in the synthesis of the purple component of color photographic and motion-picture materials, was studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 2, 2005, pp. 284–286.Original Russian Text Copyright © 2005 by Yutilov, Smolyar, Minkina.     

Kinetics and mechanism of formation of isomeric 1-methyl- and 2-methyl-5-vinyltetrazoles

The alkylation of 5-(β-dimethylaminoethyl)tetrazole (1) with dimethyl sulfate afforded 5-(β-dimethylaminoethyl)-1-methyltetrazole (2) and 5-(β-dimethylaminoethyl)-2-methyltetrazole (3). The exhaustive alkylation of compounds 2 and 3 at the terminal dimethylamino group gave 1-methyl-(4) and 2-methyl-5-(β-trimethylammonioethyl)tetrazole (5) methyl sulfates. The proton elimination from the α-methylene (with respect to the tetrazole cycle) groups of the quaternary ammonium cations of salts 4 and 5 by the action of a base leads to the corresponding zwitterions 4 ^± and 5 ^±, which in the rate-determining step undergo the cleavage of the nitrogen—carbon bond with the formation of 1-methyl-5-vinyl- (6) and 2-methyl-5-vinyltetrazole (7). The true constant of the transformation of zwitterion 4 ^± into tetrazole 6 is 21 times higher than that for the transformation of zwitterion 5 ^± into tetrazole 7.