Researches ok heterocyclic rings containing nitrogen and sulfur II. Orotylamino acids, their esters, and salts of orotic acid with amines

Esters of orotylamino acid are synthesized by reacting orotyl chloride with glycine and- and-alanine esters. Orotylamino acids are prepared by reducing the benzyl ester of orotylglycine, or by reacting orotyl chloride with sodium salts of amino acids. A series of salts of orotic acid are prepared by reacting orotic acid with amines.For Part I see [8].     

Researches on nitrogen and sulfur heterocyclic rings

A number of 7H-pyrimido[4, 5-b]thiazines are obtained by reacting 5-amino-6-mercaptopyrimidines with -halogeno ketones. It is established that the reaction takes place in three stages: formation of 5-amino-6-[-ketoalkyl(aralkyl)-mercapto]pyrimidines, cyclization of these to 6-hydroxy-5, 6-dihydropyrimido[4, 5-b][1, 4]thiazines, and dehydration of the latter to 7H-pyrimido[4, 5-b][1, 4]thiazines.For Part III see [5].     

Synthesis of pyrylium salts and heterocyclic nitrogen bases from cycloalkenylacetic acid esters

2-Alkyl-6-methoxy-3,4-tetramethylene- and 3,4-pentamethylenepyrylium perchlorates were obtained by acylation of cycloalkenylacetic acid esters with aliphatic acid anhydrides. 2-Methyl-6-methoxy[2,3-c]cholestanopyrylium perchlorate was similarly synthesized. 2-Alkyl-3,4-tetramethylene-6-pyridones were isolated by treatment of 2-alkyl-6-methoxy-3,4-tetramethylene-pyrylium perchlorates with excess concentrated ammonium hydroxide. 2-Methyl-3,4-pentamethylene-6-aminopyridine was obtained by the action of excess concentrated ammonium hydroxide on 2-methyl-6-methoxy-3,4-pentamethylenepyrylium perchlorate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1323–1326, October, 1976.     

Palladium-catalyzed, one-pot carbonylation of heterocyclic compounds into their esters, in the presence of mercury salts.

One pot carbonylation of thiophene, furan, benzofuran and pyrrole in alcohol, to produce the corresponding esters, has been carried out at room temperature, using a PdCl₂/mercury salt/Copper(II) system.     

Photoelectron spectra of molecules. II. Carboxylic acids and their esters

He I photoelectron (PE) spectra of four carboxylic acids and five esters are measured. Semiempirical and ab initio quantum chemical calculations are used for the interpretation of the spectra. The complex approach which uses empirically established relationships (the dependence of valence electron ionization energies on proton affinities in the gas phase, on the core level ionization energies, and on the structure) was developed. © 1997 John Wiley & Sons, Inc.     

The reactions of some pyraiiylideneiminium salts with amines. II

The iminium salt, N,N-dimethyl-N-[2-(2-phenyl-4H-l-benzopyran-4-ylidene)ethylidene] imin-ium perchlorate ( 3 ), reacts with secondary amines by exchanging the dimethylimino group for the added amine. Primary amines also reacted with 3 in the same manner. The bis iminium salts, N,N,N',N'-tetramethyl-N,N'-[2-(2-phenyl-4H-l-benzopyran-4-ylidene)-1,3-propanediylidene]-bis(immium perclilorate) ( 4 ) and the corresponding thiapyran derivative ( 5 ), react with ammonia to give 5-dimethylamino-2-phenyl-5H-1-benzopyrano[3,4-c]pyridine ( 10 ) and the thia analog 11 . The reactions of 4 and 5 with primary amines give 3-alkyl-5-dimethylamino-2-phenyl-5H-l-beiizopyrano[3,4-c]pyridinium perclilorate salts or the corresponding thiapyrano compounds. Compounds 4 and 5 react with secondary amines by exchanging the dimethylimino groups with the secondary amine and addition of the amine at the 2-position of the pyran or thiapyran ring.     

Computational study of iron(II) systems containing ligands with nitrogen heterocyclic groups

Density functional theory (DFT) calculations show the higher energy HOMO (highest occupied molecular orbital) orbitals of four iron(II) diimine complexes are metal centered and the lower energy LUMO (lowest unoccupied molecular orbitals) are ligand centered. The energy of the orbitals correlates with electrochemical redox potentials of the complexes. Time-dependent density functional theory (TDDFT) calculations reveal ligand centered (LC) and metal-to-ligand charge transfer (MLCT) at higher energy than experimentally observed. TDDFT calculations also reveal the presence of d-d transitions which are buried under the MLCT and LC transitions. The difference in chemical and photophysical behavior of the iron complexes compared to that of their ruthenium analogues is also addressed.     

Synthesis of new microsensor coatings and their response to vapors-III Arylphosphonic acids, salts and esters

Phosphonic acids, phosphonate esters and cyclohexylammonium phosphonates, spray-coated onto surface acoustic wave (SAW) devices, were exposed to vapors of chloroethyl ethyl sulfide (CEES), dimethyl methylphosphonate (DMMP), and water. Changes in the resonance frequency of the device or the resistance of the coating were collected by computer-controlled data acquisition. Two of the esters showed major reversible and selective response to CEES, and one of the acids showed similar behavior with DMMP.     

Polyurethanes containing sulfur. II. New thermoplastic nonsegmented polyurethanes with diphenylmethane unit in their structure

New thermoplastic nonsegmented thiopolyurethanes were synthesized from the new low‐melting aliphatic‐aromatic thiodiols bis[4‐(2‐hydroxyethyl)thiomethylphenyl]methane, bis[4‐(3‐hydroxypropyl)thiomethylphenyl]methane, and bis[4‐(6‐hydroxyhexyl)thiomethylphenyl]methane and hexamethylene diisocyanate both by melt and solution polyaddition with dibutyltin dilaurate as a catalyst. All the thiodiols were prepared with high yields by the condensation reaction of bis(4‐mercaptomethylphenyl)methane with 2‐chloroethanol, 3‐chloro‐1‐propanol, or 6‐chloro‐1‐hexanol. The hard‐segment‐type polyurethanes obtained were plastic materials with partially crystalline structures. Polymerization in solution produced products with higher molecular weights (η_red = 0.97–1.24 dL/g) than polymerization in melt (η_red = 0.44–1.05 dL/g). The structures of all the polyurethanes were determined with elemental analysis, Fourier transform infrared, and X‐ray diffraction analysis. Thermal properties of the polymers obtained in solution were examined by differential scanning calorimetry and thermogravimetric analysis. Shore A/D hardness and tensile properties for all the polyurethanes were also determined. Of the two kinds, the polyurethanes obtained in solution possessed better tensile properties and showed yield stress (tensile strength) in a range of 27.8–30.0 MPa at an elongation of 17.4–25.1%. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1767–1773, 2000     

Nickel(II) complexes of substituted diphenylcarbazones and their adducts with heterocyclic nitrogen bases

The complexing behaviour of novel 1,5-di(4-chloro-2- methylphenyl)carbazone and 1,5-di(2,4-dichlorophenyl)carbazone towards nickel(II) ions has been investigated by elemental analysis, magnetic susceptibility, u.v. -vis., i.r. and 1H-n.m.r. spectral studies. The ligands act as bidentate N,O donors and form 1:2 complexes with the metal ions. The adducting behaviour of nickel(II) complexes with nitrogen bases has been studied spectrophotometrically in a chloroform monophase. The nickel(II) di(4-chloro-2-methylphenyl)carbazonate forms hexacoordinate adducts with monodentate and bidentate bases with 1:2 and 1:1 chelate:base stoichiometries, respectively, whilst, nickel(II) di(2,4-dichloro-phenyl)carbazonate forms penta- and hexacoordinate adducts of 1:1 chelate:base stoichiometry with monodentate and bidentate bases, respectively. The results are discussed on the basis of steric properties and the basicity of the nitrogen bases.     

Derivatives of heterocyclic α-iminocarboxylic acids. 1. Syntheses of hydrazides of heterocyclic α-iminocarboxylic acids and their hydrazones

By the interaction of esters of L-proline, L-thioproline, pipecolic acid, and tetrahydro-1,4-thiazine-3-carboxylic acid with hydrazine, the corresponding hydrazides were obtained, which react with equimolar quantities of carbonyl compounds to form hydrazones consisting of mixtures of rotational isomers relative to the amide bond.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1277–1282, September, 1993.     

Synthesis of heterocyclic compounds containing germanium and nitrogen as hetero-atoms. I

Several new five- and six-membered heterocyclic compounds containing both germanium and nitrogen as hetero-atoms in the same ring were synthesized from chloro(chloromethyl)dimethylgermane. Their reactions and those of the related aminomethylgermanes are described.     

Transformation of glycyrrhizic acid. VII. Synthesis of triterpene glycopeptides containing alkyl esters of L-amino acids

The synthesis has been effected by the activated N-hydroxy succinimide ester method of new triterpene glycopeptides derived from glycyrrhizic acid, containing fragments of alkyl (ethyl, propyl, butyl) esters of L-amino acids. Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences, 45005, Ufa, Prospekt Oktyabrya, 71. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 261–268, March–April, 1994.     

Transformation of glycyrrhizic acid. VII. Synthesis of triterpene glycopeptides containing alkyl esters of L-amino acids

The synthesis has been effected by the activated N-hydroxy succinimide ester method of new triterpene glycopeptides derived from glycyrrhizic acid, containing fragments of alkyl (ethyl, propyl, butyl) esters of L-amino acids.Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences, 45005, Ufa, Prospekt Oktyabrya, 71. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 261–268, March–April, 1994.     

Determination of tertiary amines and salts of organic acids in acetic acid by catalytic thermometric titration

A new method of determination of tertiary amines and salts of organic adds in acetic acid solution, to which about 2 % of water and 8% acetic anhydride are added, is described. After the equivalence point, the excess of perchloric acid catalyses the exothermic reaction of water with acetic anhydride. The end-point is determined from the graph of temperature against volume of added titrant. If a slightly soluble compound is produced during the titration, the precision of the new method is superior to that of the potentiometric method.     

Relative energy of organic compounds II. Halides, nitrogen, and sulfur compounds

The energies of the following types of compounds are characterized by their calculated relative enthalpies: alkyl, alkenyl, and aryl halides; carboxylic acid halides; carbonyl halides; amines; carboxylic acid amides; hydrazine derivatives; nitriles; heteroaromatic compounds; nitro-compounds; organic nitrites and nitrates; organic sulfides; thiols; disulfides; sulfoxides; sulfones; organic sulfites and sulfates; and selected inorganic compounds. Stabilization energy of pyrrol and thiophene has been estimated.