Chemical properties ofN-(amidomethy)- andN-(imidomethyl)glycine derivatives 2. Reactions at alkoxycarbonyl and carboxyl groups

N-(Aroylarnmomethylfglycine amides were synthesized by reactions ofN-(aroyllminomethyl) glycine esters with ammonia. Alkaline hydrolysis ofN-(amidomethyl)glycine,N-(irnidornethyl)glycine, andN-(amidomethyl)pheriylalariiiie esters afforded the correspondingN-(amidowthyVa-amirio acids- Reactions of the Last-mentioned compounds with ethyl esters of glycine, alanine, and phenylalanine in the presence of dicyclohexylcarbodiimide yielded dipeptides containingNh-amidomethyl substituents.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1770–1771, July, 1996.     

Enantioselective Syntheses of α-Amino Acids from 10-(Aminosulfonyl)-2-bornyl Esters and Di(tert-butyl) Azodicarboxylate. Preliminary Communication

Succesive treatment of chiral esters 1 with LiN(i-Pr)₂/Me₃SiCl and di(tert-butyl) azodicarboxylate/TiCl₄/Ti(i-PrO)₄ gave N,N′ -di[(tert-butoxy)carbonyl]hydrazino esters 9 which on deacylation, hydrogenolysis, transesterification, and acidic hydrolysis furnished (2S)-α-amino acids 6 in high enantiomeric purity with efficient recovery of the auxiliary alcohol 7 .     

Synthesis ofN-(3-azido-2-nitroxypropyl)-,N-(2,3-diazidopropyl)-, andN-(2-azido-3-methoxypropyl)-N-alkylnitramines

N-(3-Azido-2-nitroxypropyl)-N-alkylnitramines andN-(2,3-diazidopropyl)-N-alkylnitramines were prepared by nitration and azidation ofN-alkyl-N-(2-hydroxy-3-chloropropyl)sulfamates andN-(3-azido-2-hydroxypropyl)-N-alkylsulfamates. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 206–208, January, 1999.     

Thermally induced isomeric transformations ofbis-(diamine) complexes of nickel(II) nitrate in the solid phase

Summary Thermal reactions of [Ni(diamine)₂(H₂O)₂](NO₃)₂ and [Ni(diamine)₂(NO₃)₂] (where diamine=1,2-ethanediamine,N-methyl-1,2-ethanediamine,N-ethyl-1,2-ethanediamine, 1,3-propanediamine andN-methyl-1,3-propanediamine) have been investigated in the solid phase. The 1,2-ethanediamine andN-methyl-1,2-ethanediamine complexes undergo thermally induced endothermic irreversible isomeric transformations. In the 1,2-ethanediamine complex the transformation is thermochromic, whereas it is not for theN-methyl-1,2-ethanediamine complex. The transformations are explained in terms of the axial interaction of NO₃ ions with nickel as well as to ligand field weakening resulting from conformational changes of the individual diamine chelate rings.Supplememtary data available: X-ray powder diffraction data (Table3).     

Synthesis and characterization of cobalt(II) and iron(III) complexes with the Schiff bases:N-(p-methylbenzylidene)-2-aminobenzimidazole andN-(benzylidene)-2-(2′-aminophenyl)-benzimidazole

Summary Reactions of CoX₂ (X=Cl, Br or NCS) and FeCl₃ with the Schiff bases:N-(p-methylbenzylidene)-2-aminobenzimidazole (pmbabi) andN-(benzylidene)-2-(2-aminophenyl) benzimidazole (bapbi) yield complexes of general formula CoL₂X₂ [except for Co(bapbi)(NCS)₂] and FeLCl₃. All complexes have been characterized by elemental analyses, i.r. spectroscopy conductivity and magnetic measurements at different temperatures; solid state and solution electronic spectra are reported for cobalt(II) complexes. The results show that the latter are pseudotetrahedral, the ligand acting as monodentate, except for Co(bapbi) (NCS)₂. On the other hand, the iron compounds probably contain pentacoordinated metal.     

Acid-catalyzed attack of the dinitrogen ligand in thecis-(Me2PhP)4Mo(N2)2 andtrans-(Ph2PCH2CH2PPh2W(N2)2 complexes by nitronium and nitrosonium cations with the formation of nitrogen oxides

The interaction of labeled dinitrogen complexescis-(Me₂PhP)₄Mo(¹⁵N₂)₂ andtrans-(dppe)₂W(¹⁵N₂)₂ with non-labeled nitronium and nitrosonium fluoroborates,¹⁴NO₂BF₄ and¹⁴NOBF₄, in sulfolane at room temperature in the presence of H₂SO₄ results in rapid formation of labeled nitrous and nitric oxides (¹⁵N¹⁴NO,¹⁵NO), as well as¹⁵N¹⁴N. The yield of the products depends on the reagent ratio and reaches 10–20 mol. % per mole of a complex under optimum conditions. The mechanism of the reactions found is proposed. It involves the step of protonation of the dinitrogen ligand to form the corresponding hydrazido(2–) derivatives, which are then attacked by nitronium or nitrosonium cations. In accordance with the mechanism proposed, it was established that the hydrazido(2–) complexes, (Me₂PhP)₃Mo(¹⁵N₂H₂)Cl₂ and (dppe)₂W(¹⁵N₂H₂)Cl₂, are capable of forming¹⁵N¹⁴NO,¹⁵NO, and¹⁵N¹⁴N under the action of¹⁴NO₂BF₄ and¹⁴NOBF₄ in the absence of an acid.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 13–13, July, 1995.     

The hindered inversion of the seven-membered ring inN-(chlorodimethylgermylmethyl)- andN-(chlorodimethylstannylmethyl)hexahydroazepin-2-ones

The stereochemical flexibility ofN-(chlorodimethylgermylmethyl)- andN-(chlorodimethylstannylmethyl)hexahydroazepin-2-ones was studied by dynamic NMR spectroscopy. Protons of the NCH₂M and MMe₂ groups (M=Ge, Sn) were shown to be anisochronic at low temperatures (<−70°C). The free activation energy of the process resulting in chemical equivalence of the protons indicated was determined. The anisochronicity of signals observed is due to the restricted inversion of the seven-membered cycle. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2379–2381, November, 1998.     

Mixed schiff base,carbonyl(phosphine)rhenium(I) complexes

Summary The Re(CO)₂(L)P₂ complexes (L=N-methylsalicylideneiminate,N-phenylsalicylideneiminate, halfN,N-ethylenebis(salicylideneiminate) or 8-hydroxyquinolinate; P=dimethyl(phenyl)phosphine or triphenylphosphine) were synthesized from the ReCl(CO)₃P₂ complexes and characterized by elemental analysis, i.r. and¹H n.m.r. spectroscopy.     

Platinum(II) and palladium(II) chlorides complexes with purine,pyrimidine,N-ethylimidazole andN-propylimidazole

Summary Platinum(II) and palladium(II) chloride complexes with purine, pyrimidine (pyrimid),N-ethylimidazole(N-EtIm) andN-propylimidazole(N-PropIm) ligands have been prepared and characterized by analysis and spectroscopic methods. The compounds have general formula M(L₁)(L₂)Cl₂ where M=Pt^II, Pd^II; L₁=purine or pyrimid, L₂=N-EtIm orN-PropIm, except the complexes Pt(purine)(pyrimid)Cl₂ and [Pd(purine)(pyrimid)₂Cl]Cl and [Pt(purine)₂ (N-propIm)Cl]Cl·2H₂O.     

Mass spectrometry of N-(Pyrimidin-2-yl)amino acids and their methyl esters

N(Pyrimidin-2-yl)-glycine, -alanine and -phenylalanine (1-3) and their methyl esters (4-6) were investigated using electron impact (EI) mass Spectrometry. The results showed that EI-induced decomposition occurs on the carboxylic group or involves the loss of R₂OH. In contrast to earlier investigations on N-(pyrimidin-4-yl)amino acids, elimination of water (in 1-3) or methanol (in 4-6) was found to be of EI-induced nature. The loss of 'COOH from M⁺ of ester 4 suggests the occurrence of a skeletal rearrangement leading to the isomeric N-methylamino acid.     

Dioxouranium(VI) complexes ofN-(orthovanillidene)-anthranilic acid andN-(vanillidene)-anthranilic acid

Summary Two structurally related reagents,N-(orthovanillidene)-anthranilic acid (H₂L¹) andN-(vanillidene)anthranilic acid (H₂L²), have been used to synthesize new uranyl complexes having different metal-ligand ratios, e.g. 11, 23 and 12 using various starting materials. The products have been isolated in the solid state and characterized by elemental analyses, molar conductances in methanol, t.g.a., electronic, i.r., and¹H n.m.r. spectral data.     

N-Formamid osalicylaldimine andN-Acetamidosalicylaldimine Complexes of Copper(II), Nickel(II) and Cobalt(II)

Summary N-formamidosalicylaldimine (H₂SF) andN-acetamidosalicylaldimine (H₂SA) complexes of Cu^II, Ni^II and Co^II have been synthesized and characterized by analytical, spectroscopic and magnetic data. The ligands coordinate to the metalvia the hydroxyl, carbonyl and imino groups to yield normal paramagnetic and insoluble complexes which decompose above 250°.     

Cobalt(II) halide complexes ofN-2-(4-picolyl)-,N-2-(6-picolyl)-andN-2-(4,6-lutidyl)-N′-phenylthioureas

Summary Co^II complexes of various stoichiometries have been isolated from reactions of the metal chlorides and bromides withN-2-(4-picolyl)-,N-2-(6-picolyl)- andN-2-(4,6-lutidyl)-N-phenylthioureas.     

Alkylation of salts ofN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxides with alkyl halides and dimethyl sulfate

Salts ofN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxides, RCH(OH)CH₂N(O)=NO⁻ M⁺ (R=Me, Prⁱ, or Bu^t; and M=Li, Na, K, Ag, NH₄, or Me₄N), were prepared. Their alkylation with alkyl halides R′X (X=Cl, Br, or I) and dimethyl sulfate was studied. Generally, alkylation afforded mixtures ofN-(β-hydroxyalkyl)-N′-alkoxydiazeneN-oxides RCH(OH)CH₂N(O)=NOR′ andO-alkyl-N-(β-hydroxyalkyl)-N-nitrosohydroxylamines RCH(OH)CH₂N(NO)OR′. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1996–2001, October, 1998.     

Convenient esterification of poly(γ-glutamic acid) produced by microorganism with alkyl halides and their thermal properties

The esterification of poly(γ-glutamic acid) (γ-PGA) produced by Bacillus subtilis F2-01 with alkyl halides was carried out at 60°C in N-methyl-2-pyrrolidinone (NMP) in the presence of sodium bicarbonate to obtain the corresponding esterified γ-PGA. The thermal properties of these γ-PGA esters were examined by differential scanning calorimetry and thermogravimetry. γ-PGA esters were more stable than free acid type γ-PGA, which decomposed at 210°C. Melting temperature (T_m) of γ-PGA esters could be observed at 230-250°C. T_m of γ-PGA n-alkyl esters reached a maximum at an alkyl chain length of n = 3. © 1995 John Wiley & Sons, Inc.     

Synthesis and structures of complexes ofN-2-nitroxyethylpicolinamide and 2-(2-pyridyl)-2-oxazoline with PdCl2

The reaction ofN,N′-bis(2-nitroxyethyl)pyridine-2,6-dicarboxamide with PdCl₂ afforded previously unknowncis-(N-2-nitroxyethylpicolinamide-N,N′)dichloropalladium(II) andcis-[2-(2-pyridyl)-2-oxazoline-N,N′]dichloropalladium(II), which were isolated as a cocrystallizate of the molecular compounds. Its structure was established by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1604–1606, August, 1999.     

Gold(I) complexes of thioamides

Summary Gold(I) forms linear [AuL₂]X complexes (X = Cl, Br, I or CIO₄) with thioacetamide and thiobenzamide, AuLX compounds with thiobenzamide (X = CI or Br),N, N-dimethylthioformamide (X = Cl, Br or 1) andN-dimethylthioacetamide (X = CI, Br or 1). Thev(AuS) vibrations are assigned in the 320-260 cm^–1 range. The i.r. spectra further suggest hydrogen bonding between the ligands and the anions. The conductivity measurements indicate dissociation of the [AuL₂]X complexes (X = halide) and coordination of X in solution.Presented in part at the XIX ICCC, Prague, 1978.     

Reaction ofN-(3,3,3-trifluoro-2-trifluoromethylprop-1-enyl)dimethylamine with MgSO4·7H2O. Synthesis of 4,4-difluoro-5-trifluoromethyl-2-(2,2,2-trifluoro-1-trifluoromethylethyl)-4H-1,3-dioxine andcis/trans-3-dimethylamino-2-trifluoromethacryloyl fluoride

4,4-Difluoro-5-trifluoromethyl-2-(2,2,2-trifluoro-1-trifluoromethylethyl)-4H-1,3-dioxine andcis/trans-3-dimethylamino-2-trifluoromethacryloyl fluoride were obtained by reaction ofN-(3,3,3-trifluoro-2-trifluoromethylprop-1-enyl)dimethylamine with MgSO₄·7H₂O. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1069–1071, May, 1997.     

Synthesis of organo-platinum(II) and -palladium(II) complexes ofN-phenyl- andN-(p-Tolyl)pyrazole

Summary When platinum(II) chloride dissolved in acetic acid containing concentrated hydrochloric acid was refluxed withN-phenylpyrazole(liphpz) andN-(p-tolyl)pyrazole (Htlpz), complexes of composition [Pt(N-C)Cl]₂ (N-C = phpz, tlpz) were obtained, in which phpz and tlpz are coordinated through nitrogen and carbon forming a five membered metallocycle. Similar palladium(II) complexes [Pd(N-C)Cl]₂ were easily prepared by the reaction of palladium(II) chloride with Hphpz and Htlpz in methanol in the presence of lithium chloride. These [M(N-C)CI]₂ complexes reacted with tri-n-butylphosphine (PBu₃) and pyridine (py) to give the adducts [M(N-C)ClL](L = PBu₃, py). Ethylenediamine(en) and acetylacetone(Hacac) gave IPd(phpz)(en)]Cl and [Pd(phpz)(acac)] respectively. These new complexes are characterized by means of¹H-n.m.r. and i.r. spectra, and probable structures are proposed.Reprints of this article are not available.     

Asymmetric synthesis ofS-alkyl-substituted (R)-cysteinesvia a chiral NiII complex of the Schiff's base of dehydroalanine with (S)-2-N-(N-benzylprolyl)aminobenzophenone

An efficient procedure was developed for the asymmetric synthesis ofS-alkyl derivatives of (R)-cysteine by nucleophilic addition of alkanethiols (BuⁿSH, Bu^tSH, ortert-C₅H₁₁SH) to the C=C bond of the dehydroalanine fragment in the Ni^II complex of the Schiff's base of Δ-Ala with (S)-2-N-(N-benzylprolyl)aminobenzophenone [(S)-BPB-Δ-Ala]Ni^II. Under conditions of thermodynamic control of the reaction, the diastereomeric excess of the complexes with the (S.R)-configuration was 88–96%. After decomposition of the complexes,(R)-S-butylcysteine,(R)-S-tert-butylcysteine, and(R)-S-tert-pentylcysteine were isolated with an enantiomeric purity of >97%. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1467–1470, August, 2000.