Hydrolysis of esters of certain substitutes of 1,3,5-triazine

The mechanism of hydrolysis of esters of triazine substitutes was studied. It was shown that hydrolysis of l-menthyl esters in both alkaline and acid media at 80–120° C takes place with cleavage of the bond between the oxygen and carbon of triazine. The bond between the oxygen and carbon of alcohol is broken at 180–200° C in acid medium. The kinetics of alkaline hydrolysis of triazine esters was studied, and it was established that the stability of the latter increases in relation to the influence of the substitute in triazine in the order: C₆H₅ < NHC₆H₅ < NHC₂H₅ < N(C₂H₅)₂. A number of new C-substitutes of triazine was synthesized.We thank Prof. A. I. Korolev for the proposal, and the attention he gave to this work.     

Über organogermaniumtrisulfinsäureester und versuche zur darstellung von tetrasulfinsäureestern des germaniums

The trisulfinic esters of germanium RGe(O₂SR′)₃ (R = R′ = CH₃; R = C₆H₅, R′ = CH₃, C₂H₅), which are sensitive to hydrolysis and temperature, are obtained by reaction of the corresponding trichlorides RGeCl₃ with anhydrous silver sulfinates. Aromatic trisulfinic esters as well as tetrasulfinic esters of germanium could not be obtained because of steric reasons. The esters, in which the RSO₂^?-residues are linked to germanium via oxygen, are investigated on the basis of their ¹H NMR, mass, IR and Raman spectra.     

Über Chalkogenolate. 196. Untersuchungen über N-(Methoxycarbimidoyl)guanidin 2. Umsetzungen mit Chlordithioameisensäureestern

On Chalcogenolates. 196. Studies on N-(Methoxycarbimidoyl)guanidine. 2. Reactions with Esters of Chlorodithioformic Acid N-(Methoxycarbimidoyl)guanidine reacts with esters of chlorodithioformic acid to produce the hitherto not known esters of N-(Methoxycarbimidoyl)guanidinedithiocarbonic acid (MCGT-R; formula see ?Inhaltsübersicht”?). By-product is the corresponding 2-amino-4-methoxy-6-alky(aryl)thio-1,3,5-triazine. MCGT-R, where R = CH₃, C₂H₅, C₆H₅, have been characterized by means of electron absorption, infrared, nuclear magnetic resonance, and mass spectra. The spectra and the related tautomeric structures of the dithioesters are discussed.     

Direct Conversion of Acylsilanes to Esters Mediated by Iron (III) and Nitrate Ions

Acylsilanes, RC(O)SiMe₃ (R = C₆H₅, p-MeOC₆H₄ and C₅H₁₁), can be converted into their corresponding carboxylic acids, when water is used as solvent, and esters when alcohol is used as solvent. This oxidation is mediated by iron (III) ions in 20-24 h or nitric acid diluted in alcohol in 2-10 h at room temperature.     

Metallkomplexe mit biologisch wichtigen Liganden. CLVII [1] Halbsandwich‐Komplexe mit Isocyanoacetylaminosäureestern und Isocyanoacetyldi‐ und tripeptidestern („Isocyano‐Peptide”︁)

Metal Complexes of Biologically Important Ligands, CLVII [1] Halfsandwich Complexes of Isocyanoacetylamino acid esters and of Isocyanoacetyldi‐ and tripeptide esters (?Isocyanopeptides”?) N‐Isocyanoacetyl‐amino acid esters CNCH₂C(O) NHCH(R)CO₂CH₃ (R = CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂, CH₂C₆H₅) and N‐isocyanoacetyl‐di‐ and tripeptide esters CNCH₂C(O)NHCH(R¹)C(O)NHCH(R²)CO₂C₂H₅ and CNCH₂C(O)NHCH(R¹)C(O)NHCH (R²)C(O)NHCH(R³)CO₂CH₃ (R¹ = R² = R³ = CH₂C₆H₅, R² = H, CH₂C₆H₅) are available by condensation of potassium isocyanoacetate with amino acid esters or peptide esters. These isocyanides form with chloro‐bridged complexes [(arene)M(Cl)(μ‐Cl)]₂ (arene = Cp*, p‐cymene, M = Ir, Rh, Ru) in the presence of Ag[BF₄] or Ag[CF₃SO₃] the cationic halfsandwich complexes [(arene)M(isocyanide)₃]⁺X^? (X = BF₄, CF₃SO₃).     

Heteroatom derivatives of aziridine V. Cleaving of ethylenimine by anhydrides of monocarboxylic acids. New method of synthesizingβ-acylaminoethyl esters of organic acids

The reaction of ethylenimine with anhydrides of monocarboxylic acids (RCO)₂O gives theβ-acylaminoethyl esters of the acids RCONHCH₂CH₂OCOR, hitherto unknown (only an ester with R=Me known). When R=C₆H₅ dibenzoylaminoethyl benzoate (C₆H₅CO)₂· · NCH₂CH₂OCOC₆H₅ is also formed. The IR spectra of the compounds prepared are studied.     

Über Chalkogenolate. 127. Diester der Cyaniminodiameisensäure NC?N(CO?OR)2 mit R = CH3, C2H5 und C6H5. Thiolyse der Diester

On Chalcogenolates. 127. Diesters of Cyanimino Diformic Acid NC? N(CO? OR)₂, where R = CH₃, C₂H₅, and C₆H₅. Thiolysis of these Diesters The diesters NC? N(CO? OR)₂ have been prepared by reaction of the sodium salt of cyanamide with the corresponding chloroformic acid ester. The thiolysis of these esters yields H₂N? CS? NH? CO? OR. The compounds with R = CH₃, C₂H₅, and C₆H₅ have been characterized by means of diverse methods.     

Hypervalent iodine in organic synthesis. A new route to α-functionalized carboxylate esters.

Aryl and alkylcarboxylate esters are converted into the corresponding α-hydroxy acids or α-alkoxyesters upon treatment with C₆H₅I(OAc)₂ and base in the appropriate solvent.     

The Gas-Chromatographic Behaviour of the Phosphoric Acid n-Alkyl Esters on Silicon Stationary Phases. Reactions on Columns

Abstract

Instability of the trialkylphosphates (RO)₃P(O), with R ? C₂H₁₁ - C₈H₁₇ has been observed when pairs of these esters were analysed on gas-chromatographic columns with silicone stationary phases, e.g., OV-17. New peaks were identified between those corresponding to the initial esters analysed separately. The Kovats retention indices were calculated for these peaks, with n-alkanes, as standards and phosphorus indices with tri-n-alkyl-phosphates as standards. The relationships between the retention indices and the number of the total carbon atoms in the molecules of the alkyl-phosphates was represented for the identification of the new peaks. The new peaks were identified as mixed phosphates with general structure (RO)z(RO)P(O), where R and R are alkyl radicals C₅H₁₁-C₆H₁₇. These phosphates are the results of interchange of alkoxy groups from the esters in the conditions of high temperature (240°C) of the chromatographic colums. The retention data of the esters examined are shown in the table.     

A simple and convenient synthesis of 3-[5-(trifluoromethyl)-1,2,3-triazol-4-yl]cinnamic acids from 4-aryl-6-(trifluoromethyl)-2H-pyran-2-ones and sodium azide

4-Aryl-6-(trifluoromethyl)-2H-pyran-2-ones and ethyl 4-aryl-6-(trifluoromethyl)-2-oxo-2H-pyran-3-carboxylates react with sodium azide to produce highly functionalized CF₃-1,2,3-triazoles: 3-[5-(trifluoromethyl)-1,2,3-triazol-4-yl]cinnamic acids and monoethyl esters of [5-(trifluoromethyl)-1,2,3-triazol-4-yl]arylmethylidene malonic acids.     

Ni-Catalyzed Borylation of Aryl Sulfoxides

A nickel/N-heterocyclic carbene (NHC) catalytic system has been developed for the borylation of aryl sulfoxides with B₂(neop)₂ (neop=neopentyl glycolato). A wide range of aryl sulfoxides with different electronic and steric properties were converted into the corresponding arylboronic esters in good yields. The regioselective borylation of unsymmetric diaryl sulfoxides was also feasible leading to borylation of the sterically less encumbered aryl substituent. Competition experiments demonstrated that an electron-deficient aryl moiety reacts preferentially. The origin of the selectivity in the Ni-catalyzed borylation of electronically biased unsymmetrical diaryl sulfoxide lies in the oxidative addition step of the catalytic cycle, as oxidative addition of methoxyphenyl 4-(trifluoromethyl)phenyl sulfoxide to the Ni(0) complex occurs selectively to give the structurally characterized complex trans-[Ni(ICy)₂(4-CF₃-C₆H₄){(SO)-4-MeO-C₆H₄}] 4 . For complex 5 , the isomer trans-[Ni(ICy)₂(C₆H₅)(OSC₆H₅)] 5 - I was structurally characterized in which the phenyl sulfinyl ligand is bound via the oxygen atom to nickel. In solution, the complex trans-[Ni(ICy)₂(C₆H₅)(OSC₆H₅)] 5 - I is in equilibrium with the S-bonded isomer trans-[Ni(ICy)₂(C₆H₅)(SOC₆H₅)] 5 , as shown by NMR spectroscopy. DFT calculations reveal that these isomers are separated by a mere 0.3 kJ/mol (M06/def2-TZVP-level of theory) and connected via a transition state trans-[Ni(ICy)₂(C₆H₅)(η²-{SO}-C₆H₅)], which lies only 10.8 kcal/mol above 5 .     

Über Chalkogenolate. 94. Untersuchungen über Trithioallophansäure 3. Ester der Trithioallophansäure [1]

On Chalcogenolates. 94. Studies on Trithioallophanic Acid. 3. Esters of Trithioallophanic Acid. The esters of trithioallophanic acid H₂N? CS? NH? CS(SR) with R = CH₃, CH₂C₆H₅ have been characterized by means of electron absorption spectra, infrared spectra, ¹H NMR spectra, and mass spectra.     

Oxidation of primary and secondary alkanols with the CeIII-LiBr-H2O2 system

Action of a novel oxidation system, Ce(NO₃)₃·6H₂O (cat.)-LiBr (cat.)-H₂O₂ (stoichiometric oxidant) on primary aliphatic C₆–C₉ alcohols gives selectively esters, whereas secondary aliphatic C₅–C₉ alcohols are converted into ketones. Selectivity of these transformations is provided by slow addition of H₂O₂ to the other reactants.     

Optisch aktive übergangsmetall-komplexe: XXXIII. Substituenteneinfluss auf die racemisierungs geschwindigkeit von (+)579und(−)579−C5H5MN(COC6H5)(NO)P(pC6H4Y)3

In the reaction of [C₅H₅Mn(CO)₂(NO)] [X] ([X] = [BF₄], [PF₆]) with p-substituted triarylphosphines P(p-C₆H₄?Y)₃ [Y = CF₃, Cl, F, C₆H₅, CH₃, OCH₃, N(CH₃)₂] the asymmetric monosubstitution products [C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃] [X] are formed, which can be converted into the neutral esters C₅H₅Mn(COOC₁₀H₁₉)(NO)P(p-C₆H₄?Y)₃ by natrium menthoxide. The diastereoisomers (+)₅₇₉^? and (?)₅₇₉^?C₅H₅Mn(COOC₁₀H₁₉)(NO)P(p-C₆H₄?Y)₃ are separated by fractional crystallisation and transformed into the enantiomeric salts (+)₅₇₉^? and (?)₅₇₉-[C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃] [X] by cleavage with HCl and precipitation with NH₄PF₆. The (+)₅₇₉^? and (?)₅₇₉^? rotating salts in the reaction with LiC₆H₅ yield the carbonyl addition products (+)₅₇₉^? and (?)₅₇₉^? C₅H₅Mn(COC₆H₅)(NO)P(p-C₆H₄?Y)₃ and the ring addition products (+)₅₇₉^? and (?)₅₇₉^?(exo-C₆H₅)C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃, which can be separated by chromatography.The salts (+)₅₇₉^? and (?)₅₇₉^?[C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃] [X] and the cyclopentadiene complexes (+)₅₇₉^? and (?)₅₇₉-(exo-C₆H₅)C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃ are configurationally stable, whereas the esters (+)₅₇₉^? and (?)₅₇₉^?C₅H₅Mn(COOC₁₀H₁₉)(NO)P(p-C₆H₄?Y)₃ and the benzoyl complexes (+)₅₇₉^? and (?)₅₇₉^?C₅H₅Mn(COC₆H₅)(NO)P(p-C₆H₄?Y)₃ epimerise or racemise in solution.The rate of racemisation of the benzoyl compounds (+)₅₇₉^? and (?)₅₇₉C₅H₅Mn(COC₆H₅)(NO)P(p-C₆H₄?Y)₃ was measured polarimetrically in the temperature range 0–45° C. It turned out that electron-releasingsubstituents Y in the ligand P(p-C₆H₄?Y)₃ increase the half-lives, whereas electron-attracting substituents decrease the half-lives. There is a linear correlation between the σ-constants of the substituents and the rate constants of the racemisation (reaction constant p = +2.14).     

Living Carbocationic Polymerization. XXI. Kinetic and Mechanistic Studies of Isobutylene Polymerization Initiated by Trimethylpentyl Esters of Different Acids

To gain increased insight into the mechanism of living polymerization of isobutylene (IB) and specifically into the effect of the structure of the initiator on the rate, we have investigated the polymerization of IB initiated by eight 2,4,4-trimethylpentyl (TMP) esters RCOO-C(CH₃)₂C(CH₃)₃ where R = -CCl₃, -CHCl₂, -CH₂C₆H₅, -CH₃ -CH(CH₃)₂, -C(CH₃)₃, -C₆H₅, and -CH=CHC₆H₅ in conjunction with BCl₃ coinitiator using CH₃Cl diluent at -30°C. The rates decreased along the sequence of these substituents from very high values (with R = -CCl₃, -CHCl₂) to very low values (R = -C(CH₃)₃, -C₆H₅, -CH=CHC₆H₅). The trend of decreasing rates was interpreted in terms of inductive effects. According to conversion-time curves obtained with the five esters R = -CH₂C₆H₅, -CH(CH₃)₂, -C(CH₃)₃ -C₆H₅, and -CH=CHC₆H₅, propagation is first order in monomer and the apparent rate constants of propagation decrease along the above sequence, suggesting the presence of inductive effects and the absence of resonance effects. With highly electron-donating substituents, i.e., with R = -CH(CH₃)₂ -C(CH₃)₃, -C₆H₅, and -CH=CHC₆H₅, chain transfer to monomer is operational, the rates of which were found to be monomolecular (zero order in monomer). Chain transfer to monomer can be avoided by increasing the polarization of the C-O bond by using slightly electron-donating or strongly withdrawing substituents (R = -CH₂C₆H₃, -CH₃ or -CHCl₂, -CCl₃) or by the use of CH₂Cl₂; both measures also result in enhanced propagation rate constants. Solvent polarity critically affects the stability of the growing chain end. By decreasing the polarity of the solvent, the decomposition temperature of the growing site decreases, leading to termination. Quenching studies have been carried out with model compounds as well as with polymerization systems and both kinds of experiments indicated the exclusion formation of t-chloro endgroups.     

Chinazolincarbonsäuren. VII. Mitteilung. Ein einfacher Zugang zu (4-Oxo-3,4-dihydrochinazolin-3-yl)-alkansäuren, (4-Oxo-3,4-dihydro-1,2,3-benzotriazin-3-yl)-alkansäuren und deren Estern

Quinazoline Carboxylic Acids. An Easy Route to (4-Oxo-3,4-dihydroquinazolin-3-yl)-alkanoic Acids, (4-Oxo-3,4-dihydro-1,2,3-benzotriazin-3-yl)-alkanoic Acids and their Esters A new route was found for the synthesis of (4-Oxo-3,4-dihydroquinazolin-3-yl)-alkanoic acids ( 8 ) and (4-Oxo-3,4-dihydro-1,2,3-benzotriazin-3-yl)-alkanoic acids ( 6 ) by cyclization of the N-(2-aminobenzoyl)amino acids 5 with HCOOH or HNO₂. 2H-3,1-Benzoxazine-2,4(1H)-diones ( 1 ) reacted with glycine esters to 2 , which were cyclized by HNO₂ to the esters 4 . Ester 4 was hydrolyzed to 6 (X = CH₂). Diones 1 reacted with the most common amino acids (as the ammonium salt of tertiary amine) to amino-alkanoic acids 5 , which were cyclized with orthoformate to 7 or 8 depending on the reaction conditions.     

Some Novel Dinuclear phenylboronates of biologically potent β‐enaminoesters: Synthesis,Spectroscopic characterization,antimicrobial activity and their antiandrogenic effect

Organoboron derivatives of biologically potent β‐enamino esters of the type [Where R = CH₃(1a), C₂H₅ (1b), C₃H₇(1c) and C (CH₃)₃ (1d)] have been prepared by the reactions of β‐enamino esters and Phenyl boronic acid [PhB (OH)₂] in 1:2 molar ratio in refluxing tetrahydrofuran (THF). All these derivatives have been characterized by physico‐chemical properties, elemental analyses and molecular weight measurements. The structures of these compounds have been proposed on the basis of IR, ¹H, ¹³C, ¹¹B NMR spectral data and GC‐mass spectrometry. Phenyl boronic acid, β‐enamino esters and their respective phenylboronates derivatives have been screened for the antibmicrobial activities against pathogenic bacteria (B. subtilis and E. coli) and fungi (A. niger and P. peniculosum) to access their growth inhibiting potential. In addition to this, antiandrogenic effect of Ligand, L^aH₂ and its boron derivative (1a) has also been tested in male albino rats.     

<Emphasis Type="Italic">N</Emphasis>-benzyl derivatives of valine esters

The reactions of methyl and ethyl esters of valine with m-bromobenzaldehyde and p-chlorobenzaldehyde in absolute methanol in the presence of magnesium sulfate yielded the corresponding azomethines (CH₃)₂CHCH(COOR¹)N=CHR² (R¹ = CH₃, C₂H₅; R² = 3-BrC₆H₄, 4-ClC₆H₄); their reduction with sodium borohydride gave N-benzyl derivatives of valine esters, (CH₃)₂CHCH(COOR¹)NHCH₂R².Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 11, 2004, pp. 1855–1857.Original Russian Text Copyright © 2004 by Yakubovich, Zhavnerko, Shirokii, Knizhnikov.This revised version was published online in April 2005 with a corrected cover date.     

Ferrocene Derivatives of Valine and Leucine

Methyl and ethyl esters of valine and leucine were reacted with ferrocenecarbaldehyde to obtain azomethines (C₅H₅)Fe(C₅H₄CH=NCHRCOOR′) whose reactions with sodium borohydride provide ferrocenylmethyl derivatives (C₅H₅)Fe(C₅H₄CH₂NHCHR⋅COOR′) [R=(CH₃)₂CH, (CH₃)₂CHCH₂; R′ = CH₃, C₂H₅]. The latter compounds react with sodium hydroxide to give, after treatment of the reaction mixtures with acetic acid, N-substituted amino acids (C₅H₅)Fe(C₅H₄CH₂NHCHRCOOH).__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 1046–1048.Original Russian Text Copyright © 2005 by Popova, Yurashevich, Cherevin, Gulevich, Reshetova, Knizhnikov.