An efficient method for the synthesis of dialkyl chlorophosphates from trialkyl phosphites using bis（trichloromethyl） carbonate

A mild and simple method for the synthesis of dialkyl chlorophosphates is described, bis（trichloromethyl） carbonate （BTC） is used as the effective reagent for the conversion of dialkyl phosphites to their corresponding dialkyl chlorophosphates under mild conditions.     

N,N-Dichloro poly(styrene-co-divinyl benzene) sulfonamide polymeric beads: an efficient and recyclable reagent for the synthesis of dialkyl chlorophosphates from dialkylphosphites at room temperature

An efficient and operationally simple method is developed for the synthesis of dialkyl chlorophosphates from dialkylphosphites using a new chlorine bearing reagent, N,N-dichloro poly(styrene-co-divinyl benzene) sulfonamide in the form of polymeric beads. The reagent afforded dialkyl chlorophosphates at room temperature, and is recyclable.     

Single step fluorination of dialkylphosphites: trichloroacetonitrile-KF as an efficient reagent for the synthesis of dialkyl fluorophosphates

The use of trichloroacetonitrile and KF mixture is described as an efficient reagent for the direct conversion of dialkylphosphites to their corresponding dialkyl fluorophosphates via in situ formation of dialkyl chlorophosphates in one-pot.     

Reaction between tert-butyl isocyanide, dialkyl acetylenedicarboxylates, and aromatic carboxylic acids: an efficient method for the synthesis of dialkyl (E)-2-{[benzoyl(tert-butyl)amino]carbonyl}-2-butenedioate derivatives

Protonation of the reactive intermediates produced in the reaction between tert-butyl isocyanide and dialkyl acetylenedicarboxylates by aromatic carboxylic acids leads to vinylnitrilium cations, which undergo nucleophilic reaction with conjugate bases of the carboxylic acids to produce dialkyl (E)-2-[(benzoyloxy)(tert-butylimino)methyl]-2-butenedioates and this intermediate rearranges to the dialkyl (E)-2-{[benzoyl(tert-butyl)amino]carbonyl}-2-butenedioate derivatives.     

A MILD METHOD FOR CONVERSION OF ALCOHOLS TO DIALKYL SULFITES BY USE OF Na2SO3/SOCl2

Alcohols are easily converted to their corresponding dialkyl sulfite under mild reaction conditions using Na₂SO₃/SOCl₂ in moderate to good isolated yields.     

C_2-symmetric BINOL-squaramide as efficient organocatalyst for the enantioselective α-amination of 1,3-dicarbonyl compounds with dialkyl azodicarboxylates

The asymmetric α-amination of 1,3-dicarbonyl compounds with dialkyl azodicarboxylates has been achieved by C2-symmetric BINOL-squaramide bearing multiple hydrogen bond donors to provide the desired products in excellent yields and enantioselectivities (up to 99% yield and 98% ee).     

Three-component synthesis and antibacterial evaluation of some novel 1,2-dihydroisoquinoline derivatives

Isoquinoline reacts with dialkyl acetylenedicarboxylates in the presence of kojic acid or8-hydroxyquinoline to generate 1,2-dihydroisoquinoline derivatives. The simplicity, mild reaction conditions and high yields of products make it an interesting process compared to other approaches. The compounds have been analyzed for antibacterial activity against Gram negative and Gram positive bacteria. The results indicated that 1,2-dihydroisoquinolines derived from kojic acid are effective against all of the studied bacteria especially against Bacillus subtilis, while the products obtained from8-hydroxyquinoline are active only against Gram positive bacteria.     

Facile,one-pot synthesis of new phenanthridine derivatives through 1,4-dipolar cycloaddition of phenantridine,activated acetylenes,and aromatic aldehydes

A facile, one-pot synthesis of new phenanthridine derivatives by a three-component reaction between phenantridine, dialkyl acetylenedicarboxylates（DAADs）, and aromatic aldehydes is described. The reaction is characterized by mild conditions, high selectivity, and tolerance to various functional groups.     

Synthesis of novel dithiocarbamates and xanthates using dialkyl azodicarboxylates: SN bond formation

A one?pot three?component route for the synthesis of a novel category of dithiocarbamates or xanthates is developed by a reaction of in-situ generated dithiocarbamic acids or xanthates with dialkyl azodicarboxylates under mild and catalyst-free conditions. The reaction is characterized by a wide scope, high efficiency and straightforward isolation protocol. The synthetic utility of the dithiocarbamates and xanthates was demonstrated on the preparation of symmetrical and unsymmetrical thioureas, isothiocyanates, and thiocarbamates.     

Tellurium Tetrachloride as an Efficient Chlorinating Agent for Di- or Trialkyl Phosphites: Novel Synthesis of Dialkyl Chlorophosphates

Various dialkyl chlorophosphates are prepared by the reaction of TeCI₄ with di-or trialkyl phosphites in good yields.     

An efficient and convenient synthesis of pentasubstituted pyrroles from alkyl acetoacetates,dialkyl acetylenedicarboxylates,and amines

A simple and efficient synthesis of pentasubstituted pyrroles has been developed using a one-pot, two-step reaction. The synthesis of a series of 4-hydroxypenta-1,3-diene-tricarboxylates from alkyl acetoacetates and dialkyl acetylenedicarboxylates in the presence of K₂CO₃, followed by cyclization with amines, gave the corresponding pyrroles in excellent yields.     

Catalytic synthesis of dialkyl sulfides from dialkyl disulfides

Dialkyl disulfides R₂S₂ where R = Me, Et, or Pr, both as individual compounds and as their mixtures, isolated from petroleum products can turn into alkanethiols and dialkyl sulfides under the action of catalysts having strong acid sites and medium-strength basic sites on their surface. In a helium atmosphere, the main conversion products are alkanethiols, while dialkyl sulfides form in low yield at a selectivity of no higher than 20%. A much higher dialkyl sulfide selectivity is attained in the reaction involving methanol. The most efficient catalyst for this reaction is alumina, with which the dialkyl sulfide selectivity is up to 99%.     

N-substituted dibutoxyphosphorylacetimidates in phosphorylation reactions

Russian Journal of General Chemistry - Reaction of N-substituted dibutoxyphosphorylacetimidates with sodium followed by phosphorylation of sodium derivatives with dialkyl chlorophosphates and...     

Efficient Route for the Synthesis of Highly Substituted Pyrroles

A mild and efficient synthesis of highly substituted pyrroles using the reaction of triphenylphosphine, α-diketone, ammonium acetate, and dialkyl acetylenedicarboxylates is described.     

Convenient route to dialkyl diselenides from alkyl tosylates. Synthesis of di(cis-myrtanyl) diselenide

A one-step method for the synthesis of dialkyl diselenides, by reaction of alkyl tosylates with sodium diselenide is described. Three variants of the synthesis, using as an example the preparation of optically active di(cis-myrtanyl) diselenide, are compared.     

Reaction of tert-butyl isocyanide and dialkyl acetylenedicarboxylates in the presence of 2-acetylbutyrolactone. Synthesis of functionalized α-methylene-γ-butyrolactones

Reaction of tert-butyl isocyanide with dialkyl acetylenedicarboxylates in the presence of 2-acetylbutyrolactone leads to the formation of dialkyl (E)-2-{(tert-butylamino)[2-oxo-4,5-dihydro-3(2H)-furanylidene]methyl}-2-butenedioates.     

One-pot synthesis of functionalized hydantoin derivatives via a four-component reaction between an amine, an arylsulfonyl isocyanate and an alkyl propiolate or dialkyl acetylenedicarboxylate in the presence of triphenylphosphine

An effective route to functionalized hydantoin derivatives is described, involving the reaction of a urea derivative resulting from the addition of a primary amine to an arylsulfonyl isocyanate, and an alkyl propiolate or dialkyl acetylenedicarboxylate in the presence of triphenylphosphine. The reactive 1:1 intermediate obtained from the addition of triphenylphosphine to the alkyl propiolate or dialkyl acetylenedicarboxylate was trapped by NH-acids such as the urea derivative to produce functionalized hydantoin derivatives.     

Thermal characteristics of solid-solid phase transitions in long-chain dialkyl ammonium salts

A series of symmetrical dialkyl ammonium salts, DC_nX, has been prepared and characterized with respect to temperature and enthalpy of solid-solid phase transitions, temperature of melting, thermal stability as well as the reversibility of the phase transitions. The number of carbon atoms, C_n, was varied between 8 and 18 and as anions X halides, nitrate, chlorate, perchlorate and hydrogen sulphate had been chosen. In dependence on chain length and anion type transition temperatures from 20 to 100 °C were observed. Mass specific solid-solid transition enthalpies reach values of 185 J g⁻¹, which makes this class of substances attractive for heat storage applications. The influence of anion type on the transition enthalpies is explained in terms of packing requirements, hydrogen bond network formation and contributions from hindered anion rotation.     

Automated solid phase extraction, on-support derivatization and isotope dilution-GC/MS method for the detection of urinary dialkyl phosphates in humans

We developed an analytical method based on solid phase extraction, on-support derivatization and isotope dilution-GC/MS for the detection of dialkyl phosphate (DAP) metabolites, dimethyl thiophosphate, diethyl thiophosphate, dimethyl dithiophosphate, and diethyl dithiophosphate in human urine. The sample preparative procedure is simple and fully automated. In this method, the analytes were extracted from the urinary matrix onto a styrene-divinyl benzene polymer-based solid phase extraction cartridge and derivatized on-column with pentafluorobenzyl bromide. The ester conjugated analytes are eluted from the column with acetonitrile, concentrated and analyzed. Compared to extraction-post extraction derivatization methods for the analysis of DAP metabolites, this on-support derivatization is fast, efficient, and less labor-intensive. Furthermore, it has fewer steps in the sample preparation, uses less solvent and produces less interference. The method is highly sensitive with limits of detection for the analytes ranging from 0.1 to 0.3 ng/mL. The recoveries were high and comparable with those of our previous method. Relative standard deviation, indicative of the repeatability and precision of the method, was 1-17% for the metabolites.     

Studies on the stability of four-membered ring chelates Part V. The stability of dialkyl dithiocarbamate chelates

This paper systematically studies the structure and the internal mechanism of the stability of sulphur-coordinated four-membered rings in chelates of dialkyl dithiocarbamate. It was found that the conjugated π electron structure of the free ligand is Π₄⁶, while in the metal chelate it is Π₄⁴. The stable chelates have strong σ- and π-coordinated bonds. The actual strain of the sulphur-coordinated four-membered ring in chelates is not as strong as assumed. It mainly depends on the atomic radius of the metal. The stronger the electronegativity of the metal, the stronger the π-coordinated bond. The stabler the four-membered ring, the weaker the intensity of the C-S vibrational band.