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This paper reports that the bulk polymerization of L-aspartic acid diethyl ester catalyzed by immobilized CAL-B at 80 °C for 24 h gives primarily (∼95%) α-linked poly(L-aspartate) in 70% yield with DPavg = 50 and regioselectivity (α/β) = 94 : 6. Plots of log{[M]0/[M]t} vs. time and DPavgvs. conversion indicate that this polymerization proceeds in a controlled manner by a chain-growth mechanism up to 90% conversion. Thereafter, competition occurs between chain growth and step mechanisms.

Closed-cell polyimide rigid foams with different Calculated Molecular Weight (Calc'd Mn) and foam density (ρ) have been prepared by thermal foaming of nadimide-endcapped imideoligomers (NAIO) powder. The NAIO powder was obtained by thermally treating of a PMR poly(amide ester) solution derived from the reaction of diethyl ester of 2,3,3′,4′-biphenyltetracarboxylic dianhydride (α-BPDE) and p-phenylenediamine (p-PDA) using monoethyl ester of cis-5-norbornene- endo-2,3-dicarboxylic acid (NE) as reactive endcapping agent in ethyl alcohol. Effect of Calc'd Mn and foam density (ρ) on mechanical and thermal properties of the polyimide rigid foams have been systematically investigated. It was found that the thermal foaming properties of NAIO powders were affected by the Calc'd Mn. The appreciate Calc'd Mn could yield polyimide foams with both high closed-cell content (Cc) (>80%) and outstanding mechanical properties. Moreover, the thermal properties were reduced by increasing of Calc'd Mn and the mechanical properties improved gradually by increasing foam densities. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3282–3291, 2013

The synthesis of nitrogen containing heterocyclic compounds from diethyl ester, formaldehyde, and various aromatic/aliphatic amines via a simple and efficient one-pot multicomponent reaction in ionic liquid is described. The catalyst can be recycled at least three times without obvious loss in catalytic activity.

A series of novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles bearing pyridine ring derivatives was synthesized from 2,6-dimethylpyridin-3,5-dicarboxylic acid diethyl ester. The structures of the compounds were characterized by use of IR, NMR, EI-MS, and elemental analysis. The structure of one compound was further confirmed by X-ray diffraction analysis. Biological assays showed that these compounds had potential insecticidal activity with especially strong regulation of the growth of 2nd instar Mythimna separata larvae. The effects on bioactivity of substituent groups on phenyl ring were also screened. .

Diethyl phthalate (1,2-benzenedicarboxylic acid diethyl ester, DEP) is one of a group of widely used plasticizers, which can lead to serious environmental problems. Because of manufacturing and application, DEP can be released into the atmosphere where it can undergo transport and chemical transformation. To assess the atmospheric behavior of pollutants, it is critical to know their atmospheric reactions. In this paper, the reaction mechanism and possible oxidation products for the OH-initiated atmospheric reaction of DEP were theoretically investigated by using the density functional theory (DFT) method. The geometries and frequencies of the reactants, intermediates, transition states, and products were calculated at the MPWB1K/6–31+G(d,p) level, and the energetic parameters were further refined by the MPWB1K/6–311+G(3df,2p) method. The present study shows that H abstractions from the CH3 and CH2 groups, as well as OH addition to the benzene ring, are energetically favorable reaction pathways for the reaction of DEP with OH radicals. Detailed degradation products are provided.

(2-Amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl esters are prepared via a single-step multi-component reaction of structurally diverse salicylaldehydes with malononitrile and triethyl phosphite using a catalytic amount of potassium phosphate in ethanol at ambient temperature. Use of potassium phosphate as an inexpensive catalyst makes the protocol more economical. Mild reaction conditions, simple work-up procedure are the added advantages of the present method.

Two ester-phosphonate analogs of cephalin of the type Structure (I). have been synthesized in the L-dipalmitoyl (R C15H31) and DL-distearoyl (R C17H35) forms. 2-Phthalimidoethylphosphonic acid was prepared by hydrogen bromide cleavage of its crude diethyl ester. Reaction of D-αβ-dipalmitin or DL-αβ-distearin with 2-phthalimidoethylphosphonyl dichloride gave, after hydrazinolysis and purification of the product on a silicic acid column, the corresponding phosphono-cephalins (I). A diether-phosphonate analog of cephalin, was prepared in high yield by condensation of with 2-hydroxyethylphthalimide and trichloroacetonitrile, followed by hydrazinolysis of the phthalyl diether phosphonocephalin.

Benzoguanamine (2,4-diamino-6-phenyl-s-triazine) and acetoguanamine (2,4-diamino-6-methyl-s-triazine) both react with an excess of ethyl chlorocarbonate; in this reaction two hydrogen atoms from the guanamines are replaced by two carbethoxy groups. The I.R. spectrum reveals that this double substitution takes place on one amino group; in consequence, the resulting compounds are derivatives of iminodicarboxylic acid diethyl ester. Upon heating above the melting point, the compounds decompose, during which process a very short occurrence of isocyanate absorption can be observed in the I.R. spectrum.

The reaction of N-sulfinyltrifluoromethanesulfonamide CF3SO2NSO with triethylphosphate and triethylphosphite results in N-(trifluoromethanesulfonyl)triethoxyphosphazene CF3SO2N=P(OEt)3, which upon heating is converted into the diethyl ester of N-trifluoromethylsulfonylamidophosphoric acid CF3SO2NHP(O)·(OEt)2. The latter was also prepared by alcoholysis of N-(trifluoromethanesulfonyl)trichlorophosphazene or of potassium salt of dichloroanhydride of N-trifluoromethylsulfonylamidophosphoric acid, or by the reaction of the salt CF3SO2NHNa with diethylchlorophosphate. Compound CF3SO2N=P(OEt)3 does not rearrange into the isomeric diethyl ester of N-ethyl-N-(trifluoromethylsulfonyl)amidophosphoric acid CF3SO2N(Et)P(O)(OEt)2, contrary to the statement in the literature on the easy rearrangement of phosphazenes RFSO2N=P(OEt)3 into amidates RFSO2N(Et)P(O)(OEt)2.

E-mail address: yjyoon@gnu.ac.kr Received July 30, 2008(4,5-Dichloro-6-oxo-6H-pyridazin-1-yl)phosphoric acid diethyl ester (3) is an efficient coupling agent forlactonization of aliphatic and aromatic ω-hydroxycarboxylic acids. Lactonization of ω-hydroxycarboxylicacids with 3 in the presence of equimolar amounts of a base gave the corresponding monoolides, diolides,triolides and/or tetraolides.Key Words : Lactonization, ω-Hydroxycarboxylic acid, (6-Oxo-6H-pyridazin-1-yl)phosphoric acid diethylester, LactoneIntroductionLactonization is an important process in the synthesis ofthe natural product.

Aromatic aldoximes were converted to the corresponding nitriles in good to excellent yields by employing phosphoric acid diethyl ester 2-phenylbenzimidazol-1-yl ester as reagent. The method was equally effective for oximes bearing electron-donating and electron-withdrawing substituents.

(4,5-Dichloro-6-oxo-6H-pyridazin-1-yl)phosphoric acid diethyl ester (3a) are efficient and selective coupling agents for the amidation of carboxylic acids. Amidation of aliphatic and aromatic carboxylic acids with aliphatic and aromatic amines using 3a under mild condition gave chemoselectively the corresponding amides in good to excellent yield. Three protected-dipeptides were also synthesized from N-BOC-Phe and O-Me-amino acid hydrochlorides using 3a under mild condition.

The synthesis and X-ray crystal structure of 1-(2,3:5,6-di-O-isopropylidene-β-D-mannofuranosyl)-1H-[1,2,3]triazol-4,5-dicarboxylic acid diethyl ester are reported. It crystallizes in the orthorhombic system with space group P212121 (No. 19); a=8.6148(5), b=10.4793(6), c=24.6873(15) A and Z=4. The solid state structure verifies the β-anomeric form of the title compound and provides evidence for the structures of the azide and chloride precursors.

Thiophene was derivatized at the β-carbon with isophthalic, dipicolinic, and four nitrobenzoic acids to yield 4-thiophen-3-yl-pyridine-2,6-dicarboxylic acid diethyl ester, I; 5-thiophen-3-yl-isophthalic acid diethyl ester, II; 2-nitro-4-thiophen-3-yl benzoic acid ethyl ester, III; 3-nitro-4-thiophen-3-yl benzoic acid ethyl ester, IV; 3-nitro-2-thiophen-3-yl benzoic acid ethyl ester, V; and 2-nitro-5-thiophen-3-yl benzoic acid ethyl ester, VI. These resulting compounds have been isolated and characterized by X-ray single-crystal diffraction. The solid-state structures of these substances are discussed as a function of the position and nature of the functional groups and the intermolecular forces. Modeling of the thiophene−aromatic ring torsion angle allowed us to attribute large differences in torsion angles to packing effects in the structures, due to π−π interactions between the aromatic rings.

Cascade reactions of 2-(2-methyl-4-oxopent-2-yloxy)benzo-σ3λ3-1,3,2-dioxaphosphole with chloral, hexafluoroacetone, mezoxalic acid diethyl ester and trifluoropyruvic acid ethyl ester are a versatile approach to the synthesis of spirophosphoranes bearing a phosphorus–carbon bond with a high yield and stereoselectivity.

A peak in the helium NMR spectrum of 3He labeled C70 is assigned to molecules containing two helium atoms. The concentration of the dihelium species is about 1/20th that of molecules containing a single helium, and the helium shift of this new species is 0.014 ppm (5.6 Hz) downfield from the resonance for molecules containing one helium. Mass spectrometry confirms the presence of dilabeled molecules. A Hirsch-Bingel transformation of the C70 to a malonate diethyl ester increases the chemical shift difference between the mono- and dihelium species.

A series of 14 4-(3′,5′-disubstituted isoxazolyl)-1,4-dihydropyridine calcium channel antagonists were examined using variable-temperature proton nuclear magnetic resonance spectroscopy and nuclear Overhauser effect (NOE) experiments. Two of these compounds, the 1,4-dihydro-2,6-dimethyl-4-[5′-methyl-3′-(4″-fluorophenyl)isoxazol-4′-yl]-3,5-pyridinedicarboxylic acid dimethyl ester (3a) and 1,4-dihydro-2,6-dimethyl-4-[5′-methyl-3′-(4″-bromophenyl)isoxazol-4′-yl]-3,5-pyridinedicarboxylic acid dimethyl ester (5a), were synthesized to assist in the clarification of ambiguities discovered in the low-temperature spectra of 1,4-dihydro-2,6-dimethyl-4-(5′-methyl-3′-phenylisoxazol-4′yl)-3,5-pyridinedicarboxylic acid diethyl ester (2b). The solid-state structure of 3a is also reported. The solution-state rotameric preferences of the 14 compounds are reported and compared with those calculated at the AM1 level. C-4—C-4′ bond rotation barriers were also calculated at the AM1 level for nine of the systems examined. Several species failed to display temperature-dependent signals associated with hindered rotation owing to highly biased rotameric equilibria at the temperatures required to freeze out the rotation. The seven experimental rotation barriers (ΔG≠ from ⩽26 to 40.4 kJ mol−1) reported are 1–6.8 kJ mol−1 higher than ΔH≠ calculated at the AM1 level.

A method has been developed for preparing the unique phospholipid phosphatidylethanol, which is a marker of human and animal alcohol intoxication and acts as an effective component of liposomal forms of medicinal compounds. The method consists of preparation of the diethyl ester of phosphatidic acid with subsequent removal of one ethyl by CsF in t-butanol.

Four hydrophobic amino acids (Leu, Tyr, Phe, Trp) were oligomerized by the protease papain in homo-oligomerization, binary co-oligomerization and ternary co-oligomerization. After 24 h, solid polydisperse reaction products of the homo-oligomerization were obtained in yields ranging from 30-80% by weight. A DPavg was calculated based on MALDI-ToF MS results using the ion counts for the chains in the product. Based on the DPavg and the yield of the homo-oligomerization it was determined that the amino acids can be ranked according to reactivity in the order: Tyr > Leu > Phe > Trp. Thermal degradation of the homo-oligomers shows two degradation steps: at 178-239 degrees C and at 300-330 degrees C. All the products left a significant amount of char ranging from 18-57% by weight at 800 degrees C. Binary co-oligomers were obtained as a polydisperse precipitate with a compositional distribution of the chains. Both the compositional and chain length distribution are calculated from MALDI-ToF mass spectra. By comparing the amount of each amino acid present in the chains it was determined that the amino acids are incorporated with a preference: Leu > Tyr > Phe > Trp. Ternary co-oligomers were also obtained as a precipitate and analyzed by MALDI-ToF MS. The compositional distribution and the chain length distribution were calculated from the MALDI-ToF data. The quantity of every amino acid in the chains was determined. Also determined was the influence on the DPavg when the oligomers were compared with corresponding binary co-oligomers. From the combined results it was concluded that in the co-oligomerization of three amino acids the reactivity preference is Leu > Tyr > Phe > Trp. Thermal degradation of all the co-oligomers showed a weight loss of 2 wt% before the main oligomer degradation step at 300-325 degrees C.

The kinetics of thermal imidization of the H-complexes derived from the diethyl ester of 3,3′,4,4′-benzophenonetetracarboxylic acid (EBZP) and various diamines have been studied. A comparison of kinetic parameters obtained for the imidization of H-complexes based on ethyl or methyl esters of this acid has disclosed the differences in the behavior of each of the two H-bonds and the contribution of each bond to the mechanism of polyimide formation from the respective H-complexes.

The crystal structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid (1) and of (±)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid (2) have been solved by X-ray methods. They are built up in a similar way to centrosymmetric dimers of hydrogen-bonded molecules. The orientation of the substituents around the central C-C bond in both molecules fulfills the requirement for the least spatial hindrance. The observed shift of theυoh stretching frequencies from 3312(1), 3346 (2) cm−1 in solid to 3408(1), 3450(2), in diluted (10−3M) tetrachloromethane solution, indicates the formation of intramolecular hydrogen-bonded species.

The title compound, C12H14O6S, is a dicarboxylic acid diethyl ester of 3,4-ethylenedioxythiophene, which is a component of electrically conductive poly(3,4-ethylenedioxythiophene) (PEDOT). The ethylene group is disordered over two sites with occupancy factors 0.64 and 0.36. Both the carbonyl groups are coplanar with the thiophene ring. The molecules form centrosymmetric dimers with an R22(12) coupling by intermolecular C—H...O hydrogen bonds [3.333 (5) Å] at the ethoxycarbonyl groups. The dimer units are arranged to form a ribbon-like molecular sheet.

The double bond formed in the Horner-Emmons reaction has only E configuration independently of the structure of the saturated linear, α-branched, and β-branched aliphatic aldehydes upon their reaction with the diethyl ester of 3-ethoxycarbonyl-2-methyl-2-propenylphosphonic acid, while the ratio of the2E,4E and2Z,4E isomers in the reaction product varies only from 58∶42 to 62∶38. An increase in the aldehyde concentration leads to an increase in the fraction of the2Z,4E isomer in the ethyl ester of 2E/Z,4E-3,7-dimethyl-2,4-octadienoic acid formed.

The title compound, C12H8N2O2, was prepared by the reaction of the diethyl ester of naphthalenebis(oxamate) with tert-BuNH2. The molecule is nearly planar, with an r.m.s. deviation of 0.017 Å from the plane through all 16 non-H atoms. In the crystal, a three-dimensional network is formed, composed of layers of molecules along the b- and c-axis directions, due to the formation of intermolecular N—H...O hydrogen bonds, as well as of chains along the a-axis direction due to parallel displaced sandwich-type π–π interactions with average distances between the interacting molecules in the range 3.35–3.40 Å.

Diethyl N-(ferrocenyl­carbonyl)­glutamate or N-ferrocenoyl-glutamate-(OEt)2, [Fe(C5H5)(C15H20O5N)], (I), is a derivative of N-ferrocenoylglutamate-(OBz)2, the corresponding benzyl ester derivative published previously [Kraatz, Lusztyk & Enright (1997). Inorg. Chem. 36, 2400–2405]. These redox-labeled amino acid structures exhibit intermolecular hydrogen bonding that leads to extended networks in the solid state and exhibit typical ferrocene one-electron reversible electro­chemical responses. The asymmetric unit of the structure contains two independent mol­ecules, in which the most notable difference is in the conformations of the diethyl ester groups.

A trans-4-[60]fullerenobisacetic acid derivative was easily obtained from its diethyl ester, which was regio- and stereoselectively prepared by the biscyclopropanation of [60]fullerene with a tethered bis(α-bromophenylacetate) derivative. The polycondensation of the resultant fullerenobisacetic acid with aromatic diamines proceeded smoothly to give the corresponding regio- and stereo-regular [60]fullerene pearl-necklace polyamides in excellent yields.

1. Esters of pentafluoroisopropenylphosphonic acid were obtained by dehydrofluorination of the corresponding esters ofα-hydrohexafluoroisopropylphosphonic acid or the loss of alkyl fluoride from hexafluoroisopropylidenetrialkoxyphosphoranes by the action of the adduct Et3N·BF3. 2. The action of catalytic amounts of Et2O·BF3 on hexafluoroisopropylidenetrimethoxyphos-phorane leads to its rearrangement to the dimethyl ester ofα-methylhexafluoroisopropylphosphonic acid, while the analogous triethoxyphosphorane loses ethyl fluoride and yields the diethyl ester of pentafluoroisopropenylphosphonic acid. In this case, unstable adducts are formed as intermediates.

The studies on reaction of newly obtained aminophosphonic acid diethyl ester derivatives of fluorene with Cr2O72−, CrO42−, CrO3Cl− and CrO3 have been investigated using electronic, infrared,Raman and NMR spectral methods. It has been found that the resulting compounds are of the type (AH)2Cr2O7, whereA stands for the organic part of the molecule. The organic cation and solvent effects on the electronic states of pseudotetrahedrally arranged Cr(VI) anions are discussed.

Four organic substrates, acetoacetic acid methyl ester, 4-chloroacetoacetic acid ethyl ester, acetonedicarboxylic acid diethyl ester, and N-methylacetoacetamide, have been found to generate dual-frequency oscillations in the Belousov–Zhabotinskii type reaction system.

1. 1S,5S-1,5-Bistrityloxymethyl-15-crown-5 (overall yield 3.6%) and 1S,5S-1,5-bistrityl-oxymethy1-24-crown-8 (overall yield 2.9%) have been obtained from D-mannitol in seven stages. 2. When the diethyl ester of 4S,8S-4,8-bistrityloxymethyl-3,6,9-trioxaundecan-1,11-dioic acid was reduced with a large excess of LiAlH4, 4S,8S-4,8-bistrityloxymethyl-3,6,9,12-tetraoxadodecan-1-ol, exhibiting the properties of a crown ether, was formed.

Isatin reacted with diethyl 3-amino-2-cyano-2-pentenedioate in ethanol and in presence of Et3N to give 3-(1-amino-2-cyano-2-ethoxycarbonylethenyl-2H-furo[2,3-b]indol-2-one. The reaction of (2-oxo-3-indolinylidene)malononitrile (3a) with the diethyl ester gave a mixture of diethyl 3-amino-4-(2-amino-3-cyano-4-quinolylcarbonyl)-2-cyano-2-pentenedioate (80%) and diethyl 3-amino-4-(2-amino-3-cyano-3aH-furo[2,3-b]indol-3a-yl)-2-cyano-2-pentanedioate (20%). Treatment of 3a and 3-[cyano(ethoxycarbonyl)]methylene-2-indolinone (3b) with 2-(ethoxycarbonylmethyl)-2-thiazolin-4-one gave the corresponding two pyrano[4′,5′-c] and furo[2″,3″-b]indole compounds, respectively. When 3a and 3b also reacted, with 3-methyl-2-pyrazolin-5-one or 3-methyl-1-phenyl-2-pyrazolin-5-one, the corresponding four spiro indoline-3,4′-(1′H)-pyrano[2,3-c]pyrazol products were obtained. The reaction of 3b with benzoylacetonitrile gave ethyl 2-amino-3a-[benzoyl(cyano)methyl]-3aH-furo[2,3-b]indole-3-carboxylate.

1. The reaction of 1,3 dipolar cycloaddition of C-benzoyl-N-phenylnitrone to dimethyl vinylphosphonate at 20° gave isomeric trans-2-phenyl-3-benzoyl-4-dimethylphosphono- and trans-2-phenyl-3-benzoyl-5-dimethylphosphonoixoxazolidines. Only the first isomer is obtained in the reaction in boiling benzene. 2. The 1,3 dipolar addition of C-benzoyl-N-phenylnitrone to the diethyl ester of β-cyanovinylphosphonic acid leads to trans-2-phenyl-3-benzoyl-4-diethylphosphono-5-cyanoisoxazolidine. 3. The cycloaddition of C,N-diphenylnitrone to the dimethyl ester of allylphosphonic acid leads to the formation of trans-2,3-diphenyl-5-dimethylphosphonomethyleneisoxazolidine, while the cycloaddition of C-benzoyl-N-phenylnitrone to this diester gives trans-2-phenyl-3-benzoyl-5-dimethylphosphonomethyleneisoxazolidine.

1. A study has been made of the stability and ESR spectra of free radicals resulting from γ irradiation at −196°C of triethylbenzene, the diethyl ester of dimethylmalonic acid, and tert-butylbenzene adsorbed on NaX and CaX zeolites at room temperature and above. Only the radicals formed from irradiation of molecules with diameters commensurate with the zeolite aperture diameters show anomalously high stability.

1. A new C-C bond on homolytic addition of dimethyl esters of succinic, glutaric, and adipic acids to the dimethyl or diethyl ester of citraconic, itaconic, and acetylenedicarboxylic acids is formed between theα-C atom of the acyl part of the ester of the alkanedicarboxylic acid and the least substituted C atom of the C=C bond of the ester of the unsaturated acid. 2. As an acceptor of radicals generated from esters of alkanedicarboxylic acids, the ester of citraconic acid is substantially less effective than the esters of maleic, itaconic, and acetylenedicarboxylic acids. The latter are close to one another in capability of forming addition products with esters of succinic, glutaric, and adipic acids. 3. The principal products of homolytic reaction of dimethyl esters of glutaric and adipic acids with the dimethyl ester of acetylenedicarboxylic acid are respectively the tetramethyl esters of 2-pentene-1,2,3,5-tetracarboxylic acid and 2-hexene-1,2,3,6-tetracarboxylic acid.

The unknown cyclohexylnitramine was prepared by the reaction of 2 moles of cyclohexylamine with 1 mole of oxalic acid diethyl ester, nitration of the N,N′-dicyclohexyloxamide formed and saponification of the N,N′-dinitro-N,N′-dicyclohexyloxamide with NH3. Several salts of cyclohexylnitramine are also described. By allowing only 1 mole of cyclohexylamine to react with 1 mole of diethyloxalate the ethyl ester of cyclohexyloxamic acid is formed in which the OC2H5 group was replaced by other radicals. Several of the compounds obtained were nitrated to give the corresponding nitramides.

1. The addition of hydride silanes to allylphosphonic dichloride and diethyl ester in presence of chlorplatinic acid or t-butyl peroxide proceeds in accordance with Farmer's rule. 2. It was shown to be possible to prepare 3-(alkylethoxysilyl)propylphosphonic ethyl esters by the Arbuzov reaction in yields of 45–80%.

1. The corresponding higher esters were obtained in yields of 65–84% by transesterification by alcoholysis of the diethyl ester of carbonic acid with higher alcohols in the presence of alkaline catalysts. 2. The best catalysts are KOH and NaOH in amounts of 3–5 mole%. Acid catalysts are relatively ineffective.

1. Three ways of synthesizing polyenic dicarboxylic acids having even numbers of double bonds are proposed. 2. A new method of synthesizing corticrocin diethyl ester is described. 3. The difficulty with which the cis bond in 6-cis-corticrocin diethyl ester is isomerized is pointed out.

Bis (trimethylsilyl) -diazene (BSD) is reduced by lithium at low temperatures to LiBSD3 (solvent: diethyl ether), LiBSD (solvent: tetrahydrofurane) or Li2BSD (solvent: diethyl ester/few tetrahydrofurane). Unlike the stable Li2BSD the compounds LiBSD3 and LiBSD decompose thermally at —15 respectively —78°. At this, LiBSD reacts to nitrogene and lithium-bis (trimethylsilyl) -amide, the latter of which forms an adduct with LiBSD, relatively stable at —45°.

The reaction of equimolar amounts of acetylacetone and diethylphosphorous acid at room temperature in the presence of sodium alcoholate gives the diethyl ester of 1-methyl-1-hydroxy-3-ketobutylphosphonic acid. When heated or when treated with water-removing agents the latter cleaves water with the formation of the diethyl ester of 1-methyl-3-keto-1-buten-1-yl-phosphonicacid. The reaction of two moles of diethyl-phosphorous acid with one mole of acetylacetone under the same conditions gave 2-oxo-2-ethoxy-3,5-dimethyl-3-hydroxy-5-diethoxyphosphono-1-oxa-2-phospholane.

Aminolysis of 3-(p-toluenesulfonoxy)hydantoin (I) through two alternative routes led to the formation of series of both methylene-diurea derivatives(II) and ω-arylsemicarbazido (N-arylacetamides) (III). 3-(p-Toluenesulfonoxy)hydantoin was found to undergo a novel kind of polymerization reaction induced by triethylamine, yielding a new polymer structure which consists of hydantoin groups combined by a hydrazinic linkage. 5-Isopropyl-3-(p-toluenesulfonoxy) hydantoin (IV) was prepared here from α-isopropylmalonic acid diethyl ester, via α-isopropylmalonohydroxamic acid (V); properties of this compound were also studied.

1. For the first time, the addition was accomplished of PCl5 to 5-phenoxypentyne-1 and 5-ethoxypentyne-1. 2. 2-Chloro-5-phenoxypentene-1-phosphinic acid, its acid chloride and dimethyl, diethyl, and dibutyl esters were prepared and characterized, and also the acid chloride and diethyl ester of 2-chloro-5-ethoxypentene-1-phosphinic acid. 3. For the first time, the dimethyl and diethyl esters of 5-phenoxypentyne-1-phosphinic acid were prepared and characterized. 4. The IR-spectra were taken of the diethyl and dibutyl esters of 2-chloro-5-ethoxypentene-1-phosphinic acid.

1. In contrast to the diethyl ester of adipic acid, the diethyl ester of cis-dihydromuconic acid is not cyclized under the conditions of the Dieckmann reaction. 2. 2-Carbethoxybicyclo[2.1.0]-2-pentanone is smoothly formed by the dehydrobromination of 2-bromo-2-carbethoxy-1-cyclopentanone with BF3 etherate.

1. Condensation in the ternary system: triethyl phosphite-formaldehyde-diethylphosphorous acid leads to the formation of the diethyl ester of ethylphosphonic acid, the diethyl ester of α-hydroxymethylphosphonic acid, diethylphosphonomethyl diethyl phosphite, bis(diethylphosphono)methyl ether, 2,5-dioxo-2,5-diethoxy-1,4,2,5-dioxadiphosphorinane, and a product with the empirical formula C8H20O6·P2, which is probably a mixture of the esters of hypophosphoric and isohypophosphoric acids. 2. The structure of the products was proved by chemical and physical methods.

The DFT, quantum-chemical calculations and thermodynamics parameters of 1-{2-[(2-hydroxyethyl)thio]ethyl}pyrrolidin-2-one (HTEP); [2-(2-oxo-pyrrolidin-1-yl)-ethyl]-phosphonic acid diethyl ester (EOEP); {[2-(2-oxopyrrolidin-1-yl)ethyl]thio}acetic acid (OETA); (2-pyridin-4-yl-ethyl]thio}acetic acid (PTA) and pyridine (PY) have been calculated with Gaussian 94 and Hybrid B3LYP functional density with 6-31G* basis set. Moreover, the electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied orbital (LUMO) energy and molecular densities have been investigated.

Starting with the diethyl ester of 3-formyl-4-ketopimelic acid we synthesized opsopyrroledicarboxylic acid in three steps.