Addition Of Sulfonate Research Articles

An approach to serrulatane diterpenes via endo-selective conjugate nucleophilic addition to arene-Cr(CO)3 complexes.

[formula: see text] Starting from a nonracemic planar-chiral arene tricarbonyl chromium complex, the serrulatane diterpenoid (+)-20-methoxy-serrulat-14-en-7,8-diol was synthesized in a highly stereoselective fashion. The key step of the synthesis is an endo-selective conjugate nucleophilic addition of lithio-methylphenyl sulfone to a 1-ethylidene-tetralin-Cr(CO)3 derivative. By employing different substrates and nucleophiles it was shown that the surprising and rather general endo selectivity must result from a unique complex induced proximity effect under participation of the Cr(CO)3 moiety.

A Two-step Synthesis of the Anti-cancer Drug (R,S)-Bicalutamide

A short, efficient synthesis of the non-steroidal antiandrogen (R,S)-bicalutamide is presented. This new route generates bicalutamide in only two steps with an overall yield of 73%. The key step is a 1,2 addition of a methyl sulfone to a keto-amide.

Theory of ionic conduction in organic solvents and gel electrolytes: application to the system DG/LiCF3SO3 and diacrylate/DG/LiCF3SO3

Gelified electrolytes have been realized by the photopolymerization of tetraethylene glycol diacrylate (TEG) or 1,3-butanediol diacrylate (BDD). The plasticizer is 2-methoxyethylether (DG) and the conductivity is obtained by the addition of lithium trifluoromethane sulfonate (LiTF). As carboxylate groups of BDD have less solvating power for Li+ ions than the ether groups of DG, the conductivity of the BDD/DG gel is dependent on the conductivity of the interstitial liquid phase only. In TEG/DG gel electrolytes, a competitive solvation for Li+ ions exists between the ether sites of TEG and DG, leading to a decrease of ionic mobilities and conductivities. A dynamical theoretical model is proposed to discuss the experimental results.

Electrochemical characterization of the effects of impurities and organic additives in lead electrowinning from fluoborate electrolyte

The effects of glue and calcium lignin sulfonate additives, and chloride and antimony impurities on the lead electrowinning process, using a fluoborate electrolyte, were studied. Short-term deposition tests, voltammetry, electrochemical impedance spectroscopy (EIS) and SEM techniques were used for the evaluation. The interactions among additives and impurities were also evaluated. The presence of antimony or chloride ion in the range of 50 to 200 mg/L was shown to cause a more dendritic and powdery lead deposit. Additions of glue and calcium lignin sulfonate at selected concentrations helped to level the deposit and counteracted the detrimental effects of chloride and antimony. The voltammetry and EIS characteristics obtained with additions of glue and calcium lignin sulfonate to the electrolyte indicated the roles of these components in modifying the lead deposition mechanisms and the deposit morphology.

Total synthesis of antitumor Goniothalamus styryllactones

Synthesis of eight enantiopure styryllactones has been achieved from a common precursor: ethyl (2 S, 3 S, 4 R)-4-( t-butyldimethylsilyloxy)-2,3-isopropylidenedioxy-4-phenylbutanoate 16, prepared in five steps and 65 % yield from ( R)-mandelic acid. Key elements for the synthesis of goniofufurone 3, goniopypyrone 4, goniobutenolides A and B ( 5, 6) and 7- epi-goniofufurone 7 were the introduction of the Z-acrylate moiety by a Julia coupling between 16 or its epimer in benzylic position and methyl 3-phenylsulfonyl orthopropionate 11 followed by a highly diastereoselective reduction of the resulting β-keto sulfone which sets up the last of the four contiguous asymmetric center. In the case of styryllactones 4 and 7, prior to the Julia coupling, the benzyl sterocenter of 16 was efficiently inverted by a Mitsunobu reaction. Goniodiol 1 and 9-deoxygoniopypyrone 2 were synthesized via an efficient coupling between the primary triflate derived from the common intermediate 16 or its epimer and Ghosez's sulfone 11 followed by lactonization and PhSO 2H elimination. Goniodiol 1 has been efficiently converted to another styryllactone: isogoniothalamin epoxide 41. Addition of the Ghosez's sulfone to an epoxide derived from the enantiomer of 16 allowed a short synthesis of 8- epi-9-deoxygoniopypyrone 8, thereby establishing that its structure is the following: (1 R, 5 R, 7 S, 8 S) -8-hydroxy -7-phenyl-2,6- dioxabicyclo[3.3.1] nonan-3-one.

Medium-caustic sulfonate additive for motor oils. Based on alkyltetralin

Effective new additives, including sulfonate additives, are required for creating high-quality motor oils which meet the requirements of current and future technology [1]. We developed a medium-caustic synthetic sulfonate additive based on alkyltetralin.

Inhibition of 2,3-dimethyl-1,4-naphthohydroquinone auto-oxidation by copper and by superoxide dismutase

2,3-Dimethyl-1,4-naphthohydroquinone undergoes auto-oxidation to the corresponding quinone at pH 7.4, with stoichiometric consumption of oxygen and formation of hydrogen peroxide. In an unpurified buffer, the rate of oxidation was low, but it increased nearly 9-fold when trace metals were removed from the buffer by treatment with Chelex resin. A similar increase in rate was achieved by addition of DTPA or bathophenanthroline sulfonate to unpurified buffer, whereas EDTA and desferal were less effective. Addition of copper to purified buffer led to inhibition of oxidation, with a 50% decrease in rate being observed at a metal concentration of 7.1 nM, and it is likely that the low auto-oxidation rate recorded in unpurified buffer was due to copper contamination of the latter. The auto-oxidation of 2,3-dimethyl-1,4-naphthohydroquinone was exceptionally sensitive to inhibition by superoxide dismutase, with a concentration of only 4.5 ng/ml being sufficient for a 50% decrease in rate, and the inhibitory effect of copper may be due to the ability of this metal to catalyse the dismutation of superoxide. Previous studies have shown that the rates of auto-oxidation of 1,4-naphthohydroquinone and 2-methyl-1,4-naphthohydroquinone are influenced by copper contamination of buffer and the present study shows that this is also true for a di-substituted naphthohydroquinone. For accurate assessment of rates of naphthohydroquinone auto-oxidation, it is important that purified buffers or appropriate chelating agents are employed.

Phenylsulfonyl-methylenation of aldonolactones

The low temperature addition of dilithiomethylphenyl sulfone to 2,3-O-isopropylidene-D-erythronolactone, and to 5-O-(tert-butyldimethylsilyl)-2,3-O-isopropylidene-D-ribofuranolactone gives the lactols 2 and 3a, respectively. Dehydration of lactol 2 in the presence of boron trifluoride etherate produces tetrahydrofuranylidene sulfones 5 and 6 in good yields. The reaction of lactol 3a under the same reaction conditions proceeds with formation of the 1′,5′-anhydro derivative 7 via competing intramolecular substitution.

Sulfonate additives for motor oils

In the interest of expanding the raw material base for the production of sulfonate additives, we have investigated the feasibility of producing sulfonates from a mixture of petroleum oil with alkyl derivatives of toluene or biphenyl.

Speciation analysis for iodine in milk by size-exclusion chromatography with inductively coupled plasma mass spectrometric detection (SEC-ICP MS)

A method allowing the determination of iodine species in milk and infant formulas was developed. It was based on the coupling of size-exclusion chromatography (SEC) with on-line selective detection of iodine by ICP MS. Iodine species were quantitatively eluted with 30 mM Tris buffer within 40 min and detected by ICP MS with a detection limit of 1 µg l–1 (as I). A systematic study of iodine speciation in milk samples of different animals (cow, goat) and humans, of different geographic origin (several European countries) and in infant formulas from different manufacturers was carried out. Whey obtained after centrifugation of fresh milk or reconstituted milk powders contained more than 95% of the iodine initially present in milk in all the samples investigated with the exception of the infant formulas in which only 15–50% of the total iodine was found in the milk whey. An addition of sodium dodecyl sulfonate (SDS) improved considerably the recovery of iodine from these samples into the milk whey. Iodine was found to be principally present as iodide in all the samples except infant formulas. In the latter, more than half of the iodine was bound to a high molecular (>1000 kDa) species. The sum of all the species recovered from a size-exclusion column accounted for more than 95% of the iodine present in a milk sample. For the determination of total iodine in milk a rapid method based on microwave-assisted digestion of milk with ammonia followed by ICP MS was optimized and validated using CRM 151 Skim Milk Powder.

Anaerobic reduction of ethene to ethane in an enrichment culture

A hydrogen-consuming methanogenic enrichment showed complete reduction of ethene to ethane. The ethene reduction was coupled to the formation of methane and addition of bromoethane sulfonate completely inhibited the reduction of ethene. At an ethene concentration of 0.8% in the gas phase (approximately 90 μmol l−1 in the liquid phase), the formation of ethane from ethene was completely inhibited and methane formation was inhibited by 85%. Three dominant microorganisms were present in the enrichment. A highly motile, oval-shaped homoacetogenic bacterium, and two long, rod-shaped methanogens. One methanogen was irregularly crooked and the other one was Methanospirillum-like. The acetogen and the irregularly crooked methanogen were isolated, but in pure culture they did not reduce ethene. So far, we have been unable to isolate the other methanogen.

Anaerobic reduction of ethene to ethane in an enrichment culture

A hydrogen-consuming methanogenic enrichment showed complete reduction of ethene to ethane. The ethene reduction was coupled to the formation of methane and addition of bromoethane sulfonate completely inhibited the reduction of ethene. At an ethene concentration of 0.8% in the gas phase (approximately 90 μmol l −1 in the liquid phase), the formation of ethane from ethene was completely inhibited and methane formation was inhibited by 85%. Three dominant microorganisms were present in the enrichment. A highly motile, oval-shaped homoacetogenic bacterium, and two long, rod-shaped methanogens. One methanogen was irregularly crooked and the other one was Methanospirillum-like. The acetogen and the irregularly crooked methanogen were isolated, but in pure culture they did not reduce ethene. So far, we have been unable to isolate the other methanogen.

Lubrication of Nonmetallic Materials

With the increased use of ceramic components in passenger cars, there is a need for a lubricant which can be used in ceramic/metal contacts. A recent study by the author showed that molybdenum dithiocarbamate (MoDTC) performed better than zinc dithiophosphate (ZDP) in ceramic/metal contact. Oils containing MoDTC provided lower wear volumes and friction coefficients for a Si3N4/cast iron pair than for a 52100/cast iron pair, while oils containing ZDP showed increased wear volumes for the Si3N4/cast iron pair than the 52100 steel/cast iron pair. In this study, the effect of calcium over-based sulfonate detergent and ashless succinimide dispersant on the antiwear and antifriction performance of MoDTC and ZDP was investigated in Si3N4/cast iron and cast iron/cast iron contacts. The addition of calcium overbased sulfonate or ashless succinimide to MoDTC or ZDP resulted in higher wear volumes for the cast iron/cast iron pair compared to cast iron/cast iron tested with MoDTC and ZDP alone. The addition of calcium overbased sulfonate and ashless succinimide to MoDTC or ZDP showed lower wear volumes than those of the cast iron/cast iron pair tested with MoDTC or ZDP containing calcium overbased sulfonate or ashless succinimide. For cast iron/Si3N4 pairs, the addition of calcium overbased sulfonate and/or ashless succinimide to ZDP increased wear volumes compared to those tested with ZDP alone. However, the addition of calcium overbased sulfonate to MoDTC did not increase the wear volumes, and the addition of calcium overbased sulfonate and ashless succinimide to MoDTC in cast iron/Si3N4 pairs increased wear volumes slightly. A time delay to reach steady-state friction coefficients was observed for cast iron tested against Si3N4 with oils containing MoDTC, calcium overbased sulfonate and ashless succinimide. The wear volumes seem to depend on the time to reach steady-state friction coefficients in cast iron/Si3N4 pairs. Presented as a Society of Tribologists and Lubrication Engineers paper at the World Tribology Congress in London, United Kingdom, September 8–12, 1997

Chemical Additives for Dust Control: What We Have Used and What We Have Learned

The Pacific Northwest region of the USDA Forest Service has been using chemical additives for dust abatement for many years. The traditional additives include dust oils, lignin sulfonate, and chlorides. Increased product costs, environmental concerns, and the continual quest for improved performance has led to consideration of other additives, including synthetic polymer emulsions, tall oil emulsions, clay additives, and penetrating asphalt emulsions. Some road tests have been performed to evaluate their suitability and cost-effectiveness. From these tests and experience, it has been learned that lignin sulfonate, chlorides, and clay additives, when properly matched to the site, have a consistent and predictable performance; polymer and tall oil emulsions, based on limited use, have provided inconsistent performance. The reason for this inconsistency has not been addressed other than the speculation that in some situations the additive did not completely cure, that the cured additive may be water soluble, or there might be variability in the quality of the manufactured product.

Anaerobic dechlorination and mineralization of pentachlorophenol and 2,4,6-trichlorophenol by methanogenic pentachlorophenol-degrading granules.

Anaerobic granules developed for the treatment of pentachlorophenol (PCP) completely mineralized 14C-labeled PCP to 14CH4 and 14CO2. Release of chloride ions from PCP was performed by live cells in the granules under anaerobic conditions. No chloride ions were released under aerobic conditions or by autoclaved cells. Addition of sulfate enhanced the initial chloride release rate and accelerated the process of mineralization of 14C-labeled PCP. Addition of molybdate (10 mM) inhibited the chloride release rate and severely inhibited PCP mineralization. This suggests involvement of sulfate-reducing bacteria in PCP dechlorination and mineralization. Addition of 2-bromoethane sulfonate slightly decreased the chloride release rate and completely stopped production of 14CH4 and 14CO2 from [14C]PCP. 2,4,6-trichlorophenol was observed as an intermediate during PCP dechlorination. On the basis of experimental results, dechlorination of 2,4,6-trichlorophanol by the granules was conducted through 2,4-dichlorophenol, 4-chlorophenol or 2-chlorophenol to phenol at pH 7.0-7.2.

Salt-induced cell lysis of Staphylococcus aureus.

Cell lysis was efficiently induced in Staphylococcus aureus by the addition of 0.3 M NaCl to exponentially growing cultures at 30 degrees C. When cells harvested at the exponential phase were incubated in buffer with NaCl, autolysis occurred. Treatment with chloramphenicol failed to induce cell lysis by NaCl. The effects of NaCl on growing cells and harvested cells were inhibited by the addition of sodium polyanethole sulfonate, subtilisin, cardiolipin, and lipoteichoic acid. These agents diminished the activity of a cell wall-lytic enzyme liberated from the cells in the presence of NaCl. Lysis induced by salt appears to be catalyzed by a similar lytic enzyme in growing and harvested cells.

Sulfonate additives for lube oils

Sulfonate additives for lube oils

Structure of experimental samples of medium-basicity sulfonate additives

Structure of experimental samples of medium-basicity sulfonate additives

Energetics and regulations of formate and hydrogen metabolism by Methanobacterium formicicum

Accumulation of formate to millimolar levels was observed during the growth of Methanobacterium formicicum species on H2−CO2. Hydrogen was also produced during formate metabolism by M. formicicum. The amount of formate accumulated in the medium or the amount H2 released in gas phase was influenced by the bicarbonate concentration. The formate hydrogenlyase system was constitutive but regulated by formate. When methanogenesis was inhibited by addition of 2-bromoethane sulfonate, M. formicicum synthesized formate from H2 plus HCO inf3 sup- or produced H2 from formate to a steady-state level at which point the Gibbs free energy (ΔG′) available for formate synthesis or H2 production was approximately -2 to -3 kJ/reaction. Formate conversion to methane was inhibited in the presence of high H2 pressure. The relative rates of conversion of formate and H2 were apparently controlled by the ΔG′ available for formate synthesis, hydrogen production, methane production from formate and methane production from H2. Results from 14C-tracer tests indicated that a rapid isotopic exchange between HCOO- and HCO inf3 sup- occurred during the growth of M. formicicum on H2−CO2. Data from metabolism of 14C-labelled formate to methane suggested that formate was initially split to H2 and HCO inf3 sup- and then subsequently converted to methane. When molybdate was replaced with tungstate in the growth media, the growth of M. formicicum strain MF on H2−CO2 was inhibited although production of methane was not Formate synthesis from H2 was also inhibited.

Phase behaviour of poly(ethylene oxide)/poly(methyl methacrylate) blends containing alkali metal salts

The effect of alkali metal salts on the phase behaviour of poly(methyl methacrylate) (PMMA)/poly(ethylene oxide) (PEO) blends was studied using d.s.c. Addition of lithium trifluoromethane sulfonate (LiT) to the normally miscible PEO/PMMA blends induced phase separation with the formation of a crystalline PEO phase, a crystalline PEO/salt complex phase and an amorphous PMMA phase. When potassium thiocyanate was used instead of LiT the mixture separated into two amorphous phases. Phase separation in these blends was not merely a result of the expected PEO/salt interaction, but also of the interaction of the salt with the PMMA. The evidence for this second interaction comes from an observed increase in the PMMA glass transition temperature with the addition of salt. Weak shifts in the carbonyl peaks in the i.r. spectra of the PMMA in the PMMA/salt mixtures suggest that the oxygen atom in the carbonyl interacts with the cation in the salt.