Conversion of arylhydrazones of bromonitroformaldehyde and arylazatrinitromethanes to 3-aryl-1,2,3,4-oxatriazolium-5-ones

Mesoionic 3-aryl-1,2,3,4-oxatriazolium-5-ones rather than 1,4-diaryl-dihydro-3,6-dinitro-1,2.,4,5-tetrazines, as previously assumed, are formed when arylhydrazones of bromonitroformaldehyde and arylazotrinitromethanes are heated in acetic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1682–1684, December, 1981.     

Rankin–Cohen Brackets and Associativity

Don Zagier introduced and discussed in Zagier [Proc Indian Acad Sci (Math Sci) 104(1) 57–75, 1994] a particular algebraic structure of the graded ring of modular forms. In this note we interpret it in terms of an associative deformation of this graded ring.     

Formation of derivatives of 5,6-dihydrooxazino- and 5,6-dihydrooxazolo[3,2-b]-1,2,4-triazole in the reaction of 1-oxoalkyl-3,5-dinitro-1,2,4-triazoles with potassium cyanide

1,3-Dihydrooxazino- and 1,3-dihydrooxazolol[3,2-b]-1,2,4-triazoles were obtained instead of the expected 3-nitro-5-cyano-1,2,4-triazole derivatives in the reaction of 1-oxoalkyl-3,5-dinitro-1,2,4-triazoles with potassium cyanide. Their formation is due to the fact that primary attack by the cyanide anion is not directed at the ring C₅ atom but rather at the carbonyl group with subsequent intramolecular replacement of the nitro group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1403–1405, October, 1981.     

Synthesis of 4-functionalyzed 2,3-bis(diethoxyphosphorylmethyl)furans

Using alkyl 4,5-bis(diethoxyphosphorylmethyl)furan-3-carboxylate as examples, we have demonstrated the possibility of synthesis of a phosphorylated analog of aglycone of the glycoside regulator of cellulose and callose synthesis, bis(phosphorylated) furoyl derivatives of natural amino acids, and phosphorus-containing derivatives of N-furyl-N′-hydroxyethylurea; these compounds are of interest for pharmacology.     

Ethyl 2-bromomethyl-5-(1,2,3-thiadiazol-4-yl)furan-3-carboxylate in reactions with O-, S-, N-, and P-nucleophiles

Reaction of ethyl 2-bromomethyl-5-(1,2,3-thiadiazol-4-yl)furan-3-carboxylate with nucleophiles of different nature was studied. It is shown that substitution of bromine with acetoxy group takes place under the action of sodium acetate in the acetic acid. Stronger bases, like phenolates, cause considerable decomposition of the labile furylthiadiazole fragment Decomposition can be avoided only when this reaction is carried out in the presence of a phase transfer catalyst under the conditions of the ion pair extraction,. In the reaction with sodium N,N-diethyl dithiocarbaminate the corresponding thioester is formed. Butanethiol and thiophenol are alkylated as potassium thiolates. In the last case S-alkylation proceeds exclusively. Reaction with excess 2-aminoethanol permits to prepare secondary amine, and the reactions with pyrrolidine, piperidine, and morpholine give the corresponding tertiary amines. Phosphorylation with triethyl phosphite under the conditions of Arbuzov reaction leads to the corresponding diethyl phosphonate. In all these transformations furylthiadiazole fragment is retained.     

Synthesis of ethyl 4,5-bis(diethoxyphosphorylmethyl)-3-furoate

Preparative procedure for 4,5-bis(diethoxyphosphorylmethyl)-3-furoate from 4-chloromethyl-3-furoate is developed. It includes substitution of chlorine with iodine, phosphorylation by means of the Arbuzov reaction, chloromethylation of 4-(diethoxyphosphorylmethyl)-3-furoate in the position 5 of the furan ring, substitution of chlorine with iodine in the obtained chloromethyl derivative, and repeated phosphorylation with triethyl phosphite. It was found that ethyl 4-(diethoxyphosphorylmethyl)-5(chloromethyl)-3-furoate reacts with sodium diethyl phosphite by two pathways. Besides usual nucleophilic substitution leading to phosphonate, transfer of the reaction center in the position 2 of the furan ring takes place. The ambident diethylphosphite anion in this case reacts at the oxygen to give tertiary phosphite. The latter is oxidized with the air oxygen to form ethyl 2-(diethoxyphosphoryloxy)-4-(diethoxyphosphorylmethyl)-5-methyl-3-furoate. Unlike that analogous iodomethyl phosphonate is phosphorylated selectively under the conditions of the Arbuzov reaction.     

Dipole moments of nitro derivatives of indazole

The dipole moments of indazole and a number of its nitro derivatives in dioxane solution were measured. The directions of the vectors of the dipole moments of indazole in the tautomeric 1-H and 2-H forms were determined to solve the problems associated with the tautomerism and the position of the substituents in the molecules. The experimental values of the dipole moments, of the investigated compounds were compared with the values calculated via a vector additive scheme. As a result it was shown that the mononitro and dinitro derivatives of indazole exist primarily in the 1-H tautomeric form, whereas the trinitro and tetranitroindazoles exist in the 2-H tautomeric form. The ratios of the isomers were calculated for compounds that have dipole moments intermediate between the 1-H and 2-H forms. A deviation between the experimental and calculated dipole moments of compounds containing two nitro groups in the ortho position was established; this may be explained by disruption of the coplanarity of the molecules or by deviation from additivity because of the introduction of strong electron-acceptor substituents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1669–1671, December, 1977.     

Synthesis and Properties of (1,3-Dioxolan-2-yl)furans

Reaction of formylfurancarboxylates with excess ethylene glycol in the presence of p-toluene-sulfonic acid gives rise to (1'3-dioxolan-2-yl)furancarboxylates. Reduction of these products with lithiumaluminum hydride proceeds with preservation of the dioxolane ring. Except for 5-(1'3-dioxolan-2-yl)(hydr-oxymethyl)-2-methyl-3-furan, the obtained alcohols are unstable. Chlorides derived from them decomposeunder conditions of the Michaelis-Becker reaction, no phosphorylation products are formed. By contrast'the above-mentioned stable alcohol by treatment with thionyl chloride in the presence of pyridine is convertedto a fairly stable chloromethylfuran. The latter compound reacts with sodium diethyl phosphite in benzene to form the corresponding phosphonate that exists as a 1:4 mixture of two spectroscopically discernible conformers.     

Vibrational spectra and structure of 1,2,4-triazole derivatives

From an analysis of the IR and Raman spectra and a calculation of the frequencies and forms of the normal vibrations of the nitrotriazoles, conclusions have been drawn on the structure of 3,5-dinitro-1,2,4-triazole and 1-methyl-3,5-dinitro-1,2,4-triazole. The nitro group in position 3 of the triazole ring is located in the plane of the molecule, and that in position 5 is rotated about the CN bond. The spatial nonequivalence of the nitro groups leads to the splitting of the absorption bands in the IR spectra that are characteristic for the anti- and synphase vibrations of the nitro groups.For Communication (II), see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1194–1198, September, 1973.