- FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
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The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
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Paragraph 0175; 0179-0180; 0186-0187; 0196-0197
(2021/06/22)
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- Efficient Palladium-Catalyzed Carbonylation of 1,3-Dienes: Selective Synthesis of Adipates and Other Aliphatic Diesters
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The dicarbonylation of 1,3-butadiene to adipic acid derivatives offers the potential for a more cost-efficient and environmentally benign industrial process. However, the complex reaction network of regioisomeric carbonylation and isomerization pathways, make a selective and direct transformation particularly difficult. Here, we report surprising solvent effects on this palladium-catalysed process in the presence of 1,2-bis-di-tert-butylphosphin-oxylene (dtbpx) ligands, which allow adipate diester formation from 1,3-butadiene, carbon monoxide, and methanol with 97 % selectivity and 100 % atom-economy under scalable conditions. Under optimal conditions a variety of di- and triesters from 1,2- and 1,3-dienes can be obtained in good to excellent yields.
- Yang, Ji,Liu, Jiawang,Ge, Yao,Huang, Weiheng,Ferretti, Francesco,Neumann, Helfried,Jiao, Haijun,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 9527 - 9533
(2021/03/08)
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- Synthesis of Branched Biolubricant Base Oil from Oleic Acid
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The mature manufacturing of synthetic lubricants (poly-α-olefins, PAO) proceeds through oligomerization, polymerization, and hydrogenation reactions of petrochemical ethylene. In this work, we utilize the inexpensive bio-derived oleic acid as raw material to synthesize a crotch-type C45 biolubricant base oil via a full-carbon chain synthesis without carbon loss. It contains several cascade chemical processes: oxidation of oleic acid to azelaic acid (further esterification to dimethyl azelate) and nonanoic acid (both C9 chains). The latter is then selectively hydrogenated to nonanol and brominated to the bromo-Grignard reagent. In a next step, a C45 biolubricant base oil is formed by nucleophilic addition (NPA) of excessive C9 bromo-Grignard reagent with dimethyl azelate, followed by subsequent hydrodeoxygenation. The specific properties of the prepared biolubricant base oil are almost equivalent to those of the commercial lubricant PAO6 (ExxonMobil). This process provides a new promising route for the production of value-added biolubricant base oils.
- Chen, Shuang,Wu, Tingting,Zhao, Chen
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p. 5516 - 5522
(2020/09/07)
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- A general platinum-catalyzed alkoxycarbonylation of olefins
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Hydroxy- and alkoxycarbonylation reactions constitute important industrial processes in homogeneous catalysis. Nowadays, palladium complexes constitute state-of-the-art catalysts for these transformations. Herein, we report the first efficient platinum-catalysed alkoxycarbonylations of olefins including sterically hindered and functionalized ones. This atom-efficient catalytic transformation provides straightforward access to a variety of valuable esters in good to excellent yields and often with high selectivities. In kinetic experiments the activities of Pd- and Pt-based catalysts were compared. Even at low catalyst loading, Pt shows high catalytic activity.
- Beller, Matthias,Dühren, Ricarda,Franke, Robert,Ge, Yao,Huang, Weiheng,Jackstell, Ralf,Liu, Jiawang,Neumann, Helfried,Schneider, Carolin,Yang, Ji
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supporting information
p. 5235 - 5238
(2020/07/30)
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- Conversion of oleic acid into azelaic and pelargonic acid by a chemo-enzymatic route
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A chemo-enzymatic approach for the conversion of oleic acid into azelaic and pelargonic acid is herein described. It represents a sustainable alternative to ozonolysis, currently employed at the industrial scale to perform the reaction. Azelaic acid is produced in high chemical purity in 44% isolation yield after three steps, avoiding column chromatography purifications. In the first step, the lipase-mediated generation of peroleic acid in the presence of 35% H2O2 is employed for the self-epoxidation of the unsaturated acid to the corresponding oxirane derivative. This intermediate is submitted to in situ acid-catalyzed opening, to afford 9,10-dihydroxystearic acid, which readily crystallizes from the reaction medium. The chemical oxidation of the diol derivative, using atmospheric oxygen as a stoichiometric oxidant with catalytic quantities of Fe(NO3)3·9·H2O, (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), and NaCl, affords 9,10-dioxostearic acid which is cleaved by the action of 35% H2O2 in mild conditions, without requiring any catalyst, to give pelargonic and azelaic acid.
- Brenna, Elisabetta,Colombo, Danilo,Di Lecce, Giuseppe,Gatti, Francesco G.,Ghezzi, Maria Chiara,Tentori, Francesca,Tessaro, Davide,Viola, Mariacristina
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- Selective monomethyl esterification of linear dicarboxylic acids with bifunctional alumina catalysts
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An environmentally friendly protocol for the selective protection of dicarboxylic acids is reported using methanol as a cheap esterifying agent and alumina as a heterogeneous catalyst; the selectivity of the process has been ascribed to a balanced acidity/basicity of the bifunctional alumina catalyst.
- Santacroce, Veronica,Bigi, Franca,Casnati, Alessandra,Maggi, Raimondo,Storaro, Loretta,Moretti, Elisa,Vaccaro, Luigi,Maestri, Giovanni
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supporting information
p. 5764 - 5768
(2016/11/06)
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- Synthesis of ceramides NS and NP with perdeuterated and specifically ω deuterated N-acyl residues
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The synthesis of 12 deuterated ceramides with either a deuteration at the last carbon atom of the amide bound fatty acid or a perdeuterated fatty acid chain is described. The ceramides were prepared starting from sphingosine or phytosphingosine and ω deuterated or perdeuterated fatty acids with PyBOP as activating agent in high yields. For the synthesis of the specifically deuterated fatty acids, dicarboxylic acids were transformed into ω deuterated alkyl bromide, which was chain elongated with blocked ω bromo alcohols by copper catalyzed Grignard coupling. Oxidation of regenerated alcohol function yields the ω deuterated fatty acids.
- Sonnenberger, Stefan,Lange, Stefan,Langner, Andreas,Neubert, Reinhard H.H.,Dobner, Bodo
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p. 531 - 542
(2016/11/06)
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- The synthesis of di-carboxylate esters using continuous flow vortex fluidics
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A vortex fluidic device (VFD) is effective in mediating the synthesis of di-esters at room temperature. Processing under ambient conditions allows for a simple and efficient synthesis, whilst operating under continuous flow addresses scalability. The rotational speed of the sample tube and the flow rate were critical variables during reaction optimization, and this relates to the behaviour of the fluid flow at a molecular level. Whilst at specific rotational speeds the tube imparts a vibrational response into the fluid flow, the flow rate dictates residence time and the ability to maintain high levels of shear stress. The combination of mechanically induced vibrations, rapid micromixing, high levels of shear stress and water evaporation results in yields up to 90% for 3.25 minutes or less residence time. These results are key for devising greener and more efficient processes both mediated by the VFD and other continuous flow platforms.
- Britton, Joshua,Dalziel, Stuart B.,Raston, Colin L.
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p. 2193 - 2200
(2016/04/19)
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- Process for preparing a carboxylic acid from a diol or from an epoxide by oxidative cleavage
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A process for preparing a carboxylic acid, by oxidative cleavage of at least one vicinal diol, or an epoxide, wherein the reaction is carried out in the presence of a catalyst and of an oxidizing agent and in the absence of solvent.
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Page/Page column 8; 9
(2016/06/28)
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- Six New Polyacetylenic Alcohols from the Marine Sponges Petrosia sp. and Halichondria sp.
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Six new polyacetylenic alcohols, termed strongylotriols A and B; pellynols J, K, and L; and isopellynol A, together with three known polyacetylenic alcohols, pellynols A, B, and C were isolated from the marine sponges Petrosia sp., and Halichondria sp. collected in Okinawa, Japan. Their planer structures were determined based on 2D-NMR and mass spectrometric analysis of the degraded products by RuCl3 oxidation. The absolute stereochemistry of isolates was examined by their Mosher's esters. The strongylotriols were found to be optically pure compounds, whereas the pellynols are diastereomeric mixtures at the C-6 position. Proliferation experiments using the HeLa and K562 cell lines suggested that the essential structural units for activity are the "hexa-2,4-diyn-1,6-diol" and "pent-1-en-4-yn-3-ol" on the termini.
- Gabriel, Adeyemi Francis,Li, Zhen,Kusuda, Ryouhei,Tanaka, Chiaki,Miyamoto, Tomofumi
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p. 469 - 475
(2015/09/07)
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- PROCESS FOR PREPARING A CARBOXYLIC ACID FROM A DIOL OR FROM AN EPOXIDE BY OXIDATIVE CLEAVAGE
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A process for preparing a carboxylic acid, by oxidative cleavage of at least one vicinal diol, or an epoxide, wherein the reaction is carried out in the presence of a catalyst and of an oxidizing agent and in the absence of solvent.
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Paragraph 0106; 0107; 0108; 0109; 0110; 0111; 0112
(2015/08/04)
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- Transformations of peroxide products of oleic acid ozonolysis at treatment with hydroxylamine and semicarbazide hydrochlorides
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Peroxide products of oleic acid ozonolysis treated with semicarbazide and hydroxylamine hydrochlorides in methanol are predominantly converted into methyl nonanoate and dimethyl nonanedioate, in 2-propanol, into isopropyl nonanoate and monoisopropyl ester of nonanedioic acid, and also into nonanenitrile, in tetrahydrofuran and in a mixture of acetic acid with dichloromethane, into nonanoic and nonanedioc acids, and also in nonanal oxime and 9-(hydroxyimino)nonanoic acid.
- Ishmuratov, G. Yu.,Yakovleva,Botsman,Legostaeva, Yu. V.,Nazarov,Baidimirov
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p. 610 - 614
(2015/07/02)
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- Metal/bromide autoxidation of triglycerides for the preparation of FAMES to improve the cold-flow characteristics of biodiesel
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Triglyceride autoxidation using a homogeneous Co/Mn/Zr/bromide catalyst in acetic acid (93%) of low grade tallow, canola oil or soy bean oil in a batch reactor at 150 °C for 2 h, produced lower molecular weight products relative to the fatty acids of the starting triglycerides. For the autoxidation of tallow the main products after esterification were monoesters Me(CH 2)mC(O)OMe (m = 5-12) and diesters MeOC(O)(CH 2)nC(O)OMe, (n = 7-12). Oxidation of the saturated fatty acids in triglycerides was confirmed and modelled using methyl palmitate. Post-treatment esterification of tallow autoxidation products to produce biodiesel (BD) esters resulted in improved cold temperature properties by a mean of 13.0 °C, i.e. a mean cloud point (CP) 1.0 °C (cf. unmodified tallow biodiesel: CP 14 °C).
- Phung, Peter,Rowlands, William N.,Thiyakesan, Appadurai,Benndorf, Paul,Masters, Anthony F.,Maschmeyer, Thomas
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p. 162 - 168
(2014/07/07)
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- METHOD FOR PREPARING CARBOXYLIC ACIDS BY OXIDATIVE CLEAVAGE OF A VICINAL DIOL
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The present invention relates to a method for preparing carboxylic acids, in particular mono- and dicarboxylic acids, by oxidative cleavage of a vicinal diol. According to the invention, said method consists of reacting a vicinal diol of formula I: where: p is an integer comprised between 1 and 6; R1 and R2 are, separately: an alkyl or hydroxyl group having 1 to 12 carbon atoms;a —(CH2)n—C02M group where n, which can be identical or different in R1 and R2, is an integer comprised between 1 and 11 and M is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms or an alkaline cation; or R1 and R2 jointly form an alkylene —(CH2)m- group where m is an integer comprised between 2 and 10, preferably between 2 and 6; with industrial-grade sodium hypochlorite (or bleach), in the absence of an organic solvent and without adding a catalyst, preferably at room temperature. The invention can be used for recycling natural vegetable oils.
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-
Paragraph 0074; 0075; 0076; 0077
(2013/06/04)
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- Efficient ruthenium-catalysed oxidative cleavage of methyl oleate with hydrogen peroxide as oxidant
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The oxidative cleavage of alkenes leads to the formation of carboxylic acids. One of the few technical processes using this reaction is the production of azelaic acid via the ozonolysis of oleic acid. Because of the need for stoichiometric amounts of the expensive oxidant ozone, together with safety hazards, there is still a requirement for a catalytic process using a cheap and environmentally friendly oxidant. In the present work, the oxidative cleavage of methyl oleate by hydrogen peroxide was catalysed by an easily available ruthenium precursor with dipicolinic acid as ligand. The systematic optimisation of the reaction led to the formation of azelaic acid monomethyl ester in high yields amounting to 86%. The investigation of the reaction pathway showed that the reaction proceeds via a tandem reaction of epoxidation and hydrolysis of the epoxide and oxidative cleavage of the vic-diol. The Royal Society of Chemistry.
- Behr, Arno,Tenhumberg, Nils,Wintzer, Andreas
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p. 172 - 180
(2013/04/23)
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- Compound With Carboxyl Acid Group And Amide Group And Application Thereof
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The present invention discloses compounds with a carboxyl acid group and an amide group which also containing the tertiary amino groups. The carboxyl acid group having a partial negative charge can attract the tertiary amino group with each other to form a quaternary ammonium salt structure, so that the compounds are easy to dissolve in water. Moreover, these compounds having a mushroom tyrosinase-inhibition effect and have the potential to use in the cosmetics for skin whitening.
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Page/Page column 4
(2011/04/18)
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- Compound with carboxyl acid group and amide group and application thereof
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The present invention discloses compounds with a carboxyl acid group and an amide group which also containing the tertiary amino groups. The carboxyl acid group having a partial negative charge can attract the tertiary amino group with each other to form a quaternary ammonium salt structure, so that the compounds are easy to dissolve in water. Moreover, these compounds having a mushroom tyrosinase-inhibition effect and have the potential to use in the cosmetics for skin whitening.
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Page/Page column 10
(2011/04/18)
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- Iridium-catalyzed oxidative methyl esterification of primary alcohols and diols with methanol
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Oxidative methyl esterification of primary alcohols and diols with methanol was successfully achieved, using acetone as a hydrogen acceptor, under the influence of an iridium complex combined with 2-(methylamino)ethanol (MAE) as catalyst.
- Yamamoto, Nobuyuki,Obora, Yasushi,Ishii, Yasutaka
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experimental part
p. 2937 - 2941
(2011/05/30)
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- Product recovery from ionic liquids by solvent-resistant nanofiltration: Application to ozonation of acetals and methyl oleate
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In this work we tackle the problematic separation of reaction products from ionic liquid media. Solvent-resistant nanofiltration proves to be an attractive technique for the separation of non-volatile polar products from ionic liquids. In view of the high compatibility between ozone and ionic liquids, two ozone-mediated model reactions were chosen: firstly the oxidation of acetals to esters in the presence of ozone and secondly the ozonation of methyl oleate to monomethyl azelate and pelargonic acid. The objective was to retain the ionic liquid phase by means of a solvent-resistant nanofiltration membrane, while the organic reaction products permeate through the polymeric membrane. First, the ozonations were studied in order to know the characteristic product compositions. Next, a screening of membranes was performed on synthetic product mixtures. The second generation polyimide-based DuraMem membranes showed the highest rejection, up to 96%, for the evaluated ionic liquids. These DuraMem membranes also proved suitable for the separation of the products on real reaction mixtures, even in a single filtration step.
- Van Doorslaer, Charlie,Glas, Daan,Peeters, Annelies,Cano Odena, Angels,Vankelecom, Ivo,Binnemans, Koen,Mertens, Pascal,De Vos, Dirk
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scheme or table
p. 1726 - 1733
(2011/02/22)
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- Two-step biocatalytic route to biobased functional polyesters from ω-carboxy fatty acids and diols
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Biobased ω-carboxy fatty acid monomers 1,18-cis-9-octadecenedioic, 1,22-cis-9-docosenedioic, and 1,18-cis-9,10-epoxy-octadecanedioic acids were synthesized in high conversion yields from oleic, erucic and epoxy stearic acids by whole-cell biotransformations catalyzed by C. tropicalis ATCC20962. Maximum volumetric yields in shake-flasks were 17.3, 14.2, and 19.1 g/L after 48 h conversion for oleic acid and 72 h conversions for erucic and epoxy stearic acids, respectively. Studies in fermentor with better control of pH and glucose feeding revealed that conversion of oleic acid to 1,18-cis-9-octadecenedioic acid by C. tropicalis ATCC20962 occurred with productivities up to 0.5 g/L/h. The conversion of ω-carboxy fatty acid monomers to polyesters was then studied using immobilized Candida antarctica Lipase B (N435) as catalyst. Polycondensations with diols were performed in bulk as well as in diphenyl ether. The retension of functionality from fatty acid, to ω-carboxy fatty acid monomer and to corresponding polyesters resulted in polymers with with unsaturated and epoxidized repeat units and Mw values ranging from 25000 to 57000 g/mol. These functional groups along chains disrupted crystallization giving materials that are low melting (23-40 °C). In contrast, saturated polyesters prepared from 1,18-octadecanedioic acid and 1,8-octanediol have correspondingly higher melting transitions (88 °C). TGA results indicated that all synthesized polyesters showed high thermal stabilities. Thus, the preparation of functional monomers from C. tropicalis ω-oxidation of fatty acids provides a wide range of new monomer building blocks to construct functional polymers.
- Yang, Yixin,Lu, Wenhua,Zhang, Xiaoyan,Xie, Wenchun,Cai, Minmin,Gross, Richard A.
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experimental part
p. 259 - 268
(2010/11/18)
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- Supercritical-fluid-assisted oxidation of oleic acid with ozone and potassium permanganate
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The goal of this research was to determine if any advantages could be realized by conducting the oxidation of oleic acid with ozone and potassium permanganate in supercritical carbon dioxide (SC-CO2). The ozonolysis of oleic acid without SC-CO
- Sparks, Darrell L.,Antonio Estevez,Hernandez, Rafael
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experimental part
p. 986 - 993
(2010/04/23)
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- Ozonolysis of alkenes and study of reactions of polyfunctional compounds: LXVIII. Investigation of transformations of peroxide products of olefins ozonolysis treated with hydroxylamine hydrochloride
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Hydroxylamine hydrochloride efficiently reduces peroxide products of olefins ozonolysis into carbonyl compounds. Depending on the substrate character, solvent, and the treatment conditions the arising aldehydes transformed along the route aldehyde→aldoxime→nitrile→ester into individual compounds or their mixtures, or give the corresponding acetals.
- Ishmuratov,Shayakhmetova,Yakovleva,Legostaeva,Shitikova,Galkin,Tolstikov
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p. 1114 - 1119
(2008/03/11)
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- Biodiesel additive and method of preparation thereof
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Fuel oxygenates comprised of fatty acid or fatty acid ester derivatives which have been reacted with ozone; a base; and a lower alkanol (1 to 8 carbon atoms) are described. The oxygenates comprise ester groups at a point of cleavage by the ozone which provide oxygen in the oxygenate.
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Page/Page column 4-5
(2008/06/13)
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- Ruthenium catalysed oxidation without CCl4 of oleic acid, other monoenic fatty acids and alkenes
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Ruthenium catalysed oxidation of alkenes and monoenic fatty acids is reported. The study of the influence of cosolvents (H2O/MeCN/X) shows that toxic CCl4 initially used in the Sharpless system (H 2O/MeCN/CCl4) can be avoided and demonstrates that the oxidative cleavage of CC bond could be accomplished in good yields with H 2O/MeCN/AcOEt solvent system in a ratio 3/2/2, respectively.
- Zimmermann, Fran?ois,Meux, Eric,Mieloszynski, Jean-Luc,Lecuire, Jean-Marie,Oget, Nicolas
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p. 3201 - 3203
(2007/10/03)
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- Identification and quantification of aerosol polar oxygenated compounds bearing carboxylic or hydroxyl groups. 1. Method development
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In this study, a new analytical technique was developed for the identification and quantification of multifunctional compounds containing simultaneously at least one hydroxyl or one carboxylic group, or both. This technique is based on derivatizing first the carboxylic group(s) of the multifunctional compound using an alcohol (e.g., methanol, 1-butanol) in the presence of a relatively strong Lewis acid (BF3) as a catalyst. This esterification reaction quicldy and quantitatively converts carboxylic acids to their ester forms. The second step is based on silylation of the ester compounds using bis(trimethylsilyl) trifluoroacetamide (BSTFA) as the derivatizing agent. For compounds bearing ketone groups in addition to carboxylic and hydroxyl groups, a third step was used based on PFBHA derivatization of the carbonyls. Different parameters including temperature, reaction time, and effect due to artifacts were optimized. A GC/MS in EI and in methane-CI mode was used for the analysis of these compounds. The new approach was tested on a number of multifunctional compounds. The interpretation of their EI (70 eV) and CI mass spectra shows that critical information is gained leading to unambiguous identification of unknown compounds. For example, when derivatized only with BF3-methanol, their mass spectra comprise primary ions at m/z M .+ + 1, M.+ + 29, and M.- - 31 for compounds bearing only carboxylic groups and M.- + 1, M.+ + 29, M.+ - 31, and M+. - 17 for those bearing hydroxyl and carboxylic groups. However, when a second derivatization (BSTFA) was used, compounds bearing hydroxyl and carboxylic groups simultaneously show, in addition to the ions observed before, ions at m/z M.+ + 73, M .+ - 15, M.+ - 59, M.+ - 75, M.+ - 89, and 73. To the best of our knowledge, this technique describes systematically for the first time a method for identifying multifunctional oxygenated compounds containing simultaneously one or more hydroxyl and carboxylic acid groups.
- Jaoui,Kleindienst,Lewandowski,Edney
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p. 4765 - 4778
(2007/10/03)
-
- Syntheses and QSAR studies of sorbic, cinnamic and ricinoleic acid derivatives as potential antibacterial agents
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Amides and esters of sorbic, cinnamic and ricinoleic acid have been synthesized and evaluated for their antibacterial activity against gram (+) ve S. aureus, B. subtilis and gram (-) ve E. coli. Most of the compounds have shown moderate to good activity against microorganisms under test. Linear regression analysis of descriptors related to lipophilicity, steric and electronic parameters against antibacterial activity have been performed. QSAR studies indicated the predominance of electronic and steric parameters over the lipophilicity parameters in contributing antibacterial activity.
- Narasimhan,Kothawade,Pharande,Mourya,Dhake
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p. 2828 - 2834
(2007/10/03)
-
- Transformations of higher terpenoids: IV. Synthesis and spectral parameters of glycyrrhetinic acid derivatives containing amino acid fragments
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New glycyrrhetinic acid derivatives containing amino acid and amino ester fragments were synthesized as potential biologically active substances. NMR spectra of the newly synthesized compounds were studied, and assignment of signals of the C8 and C14 carbon atoms in the terpenoid fragment was refined.
- Petrenko,Petukhova,Shakirov,Shul'ts,Tolstikov
-
p. 982 - 995
(2007/10/03)
-
- α-nitrocycloalkanones as a source of α,ω,-dicarboxylic acid dimethyl esters
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α,ω-Dicarboxylic acid dimethyl esters arc easily obtained by ring cleavage of α-nitrocycloalkanones. Thus, reaction of the latter compounds with three equivalents of potassium persulfate, in methanol and in presence of sulfuric acid at 80 °C, provides α,ω-dicarboxylic acid dimethyl esters in high yields. Long-chain, and alkylated α,ω-dicarboxylic acid dimethyl esters can be also efficiently obtained.
- Ballini, Roberto,Bosica, Giovanna
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p. 16131 - 16138
(2007/10/03)
-
- Process for the production of alcohols and diols
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A process is described for the production of a hydroxylic compound selected from alcohols and diols by hydrogenation of a hydrogenatable material selected from monoesters of carboxylic acids, monoesters of dicarboxylic acids, diesters of dicarboxylic acids, aldehydes, olefinically unsaturated aldehydes, and mixtures of two or more thereof, which process comprises the steps of: (a) providing a hydrogenation zone containing a charge of a granular hydrogenation catalyst which has a total surface area of at least about 15 m2 /g, a pore size distribution such that more than 50% of the pore volume is provided by pores in the size range less than about 40 nm, and a surface area distribution such that more than 50% of the total surface area is provided by pores in the size range of from about 7 nm to about 40 nm; (b) supplying to the hydrogenation zone a feed stream of a mixture containing hydrogen and the hydrogenatable material; (c) maintaining the hydrogenation zone under temperature and pressure conditions which are conducive to effecting hydrogenation of the hydrogenatable material; and (d) recovering from the hydrogenation zone a product stream comprising the hydroxylic compound. The process is exemplified by the hydrogenation of dimethyl 1,4-cyclohexanedicarboxylate to yield 1,4-cyclohexanedimethanol.
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-
-
- Hydrogenation process for the preparation of alcohols and diols utilizing gas and liquid phases
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A process is described for the production of a hydroxylic compound selected from alcohols and diols by hydrogenation of a corresponding hydrogenatable material selected from monoesters of carboxylic acids, monoesters of dicarboxylic acids, diesters of dicarboxylic acids, lactones, and mixtures of two or more thereof which comprises: (a) providing a hydrogenation zone containing a charge of a granular heterogeneous ester hydrogenation catalyst; (b) supplying to the hydrogenation zone a vaporous feed stream containing hydrogen and a hydrogenatable material selected from monoesters of carboxylic acids, monoesters of dicarboxylic acids, diesters of dicarboxylic acids, lactones, and mixtures of two or more thereof, at an inlet temperature which is above the dew point of the mixture; (c) maintaining the hydrogenation zone under temperature and pressure conditions which are conducive to effecting hydrogenation of esters; (d) recovering from the hydrogenation zone a two phase product stream containing a hydroxylic compound selected from alcohols and diols at an exit temperature which is below its dew point. In a preferred process the hydrogenatable material comprises dimethyl cyclohexanedicarboxylate.
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-
-
- A Synthesis of (Z)-Octadec-9-enedioic Acid
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The monomethyl ester of azelaic acid was transformed into two fragments, namely triphenylphosphonium bromide and methyl 9-oxononanoate.A Wittig reaction between these two fragments produced dimethyl (Z)-octadec-9-enedioate and subsequent hydrolysis gave the title diacid.Interestingly, the same acid was available directly from oleic acid in a published procedure which utilized a mutant strain of Candida tropicalis.
- Brunow, Goesta,Stick, Robert V.,Syrjaenen, Kaisa,Tilbrook, D. Matthew G.,Williams, Spencer J.
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p. 1893 - 1898
(2007/10/03)
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- Mg/MeOH mediated intramolecular reductive cyclization of activated dienes
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Facile intramolecular cyclisation of activated tethered dienes mediated by magnesium in methanol at room temperature is described.
- Chavan, Subhash P.,Ethiraj, Krishna S.
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p. 2281 - 2284
(2007/10/02)
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- Oxidative Cleavage of Mono-, Di-, and Trisubstituted Olefins to Methyl Esters through Ozonolysis in Methanolic NaOH
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The ozonolysis of alkenes in methanolic NaOH or NaOMe with CH2Cl2 as cosolvent leads directly to methyl esters.The procedure has been used to prepare various α-, β-, and ω-alkoxy esters, acyloxy esters, and α- and β-N-acyl and N-sulfonyl esters from appropriate unsaturated ethers, esters and amides.Other examples include the formation of dimethyl octanedioate from cyclooctene (75percent yield), dimethyl nonanedioate and methyl nonaoate from methyl oleate (77 and 78percent, respectively), and tetradecanoic acid γ-lactone from 2-methyl-2-hexadecen-6-ol (80percent yield).
- Marshall, James A.,Garofalo, Albert W.
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p. 3675 - 3680
(2007/10/02)
-
- Ozonolysis of Olefins, V : Emulsion Ozonization of Methyl Linoleate and Methyl Linolenate in Aqueous Alkaline Hydrogen Peroxide
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The ozonolysis of methyl linoleate and methyl linolenate in neutral and alkaline aqueous emulsions of hydrogen peroxide was investigated.Besides the expected products such as dimethyl malonate (3b), dimethyl azelate (3h) and methyl hexanoate (2a) further homologous methyl esters of dicarboxylic acids (3a-g), oxo carboxylic acids (4a, b, e-h) and hydroxy carboxylic acids (4c, d) could be detected by GC/MS analysis.Furthermore a method for separation of 8-hydroxyoctanoic acid (4d) by methylation and extraction of the reaction mixture containing the ozonolysis products is described. Keywords.Ozonization; Fatty esters; 8-Hydroxyoctanoic acid.
- Poklukar, Norbert,Mittelbach, Martin
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p. 719 - 724
(2007/10/02)
-
- New Method for the Selective Reduction of Amides
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A new procedure was developed for the reduction of tertiary aliphatic, olefinic, and aromatic amides to aldehydes.Reaction of the amides (1), (5), (7), (9), (11), (13), (15), and (17) with ethyl or methyl trifluoromethanesulphonate in CH2Cl2 at room temperature and then with L-Selectride at -78 deg C gave the corresponding aldehydes (2), (6), (8), (10), (12), (14), (16), and (18), respectively.A second functional group, including CO2R, C=C, CH(OCH2CH2O), and CN, in these amides was found to be inert under the conditions employed.These selective reductions gave the desired aldehydes in 50-73percent isolated yields and in >95percent yields based on converted amides.
- Tsay, Shwu-Chen,Robl, Jeffrey A.,Hwu, Jih Ru
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p. 757 - 759
(2007/10/02)
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- Ozonolysis of Olefins, II; Linseed Oil as a Renewable Resource for Alkyl 3,3-Dialkoxypropanoates
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A new approach to the synthesis of alkyl 3,3-dialkoxypropanoates, which are important intermediates in organic synthesis, starting from fatty esters is described.Thus, ozonolysis of methyl linoleate and methyl linolenate in alcoholic hydrogen chloride affords a reaction mixture, from out of which the alkyl 3,3-dialkoxypropanoates can be isolated by fractional distillation in 60-65percent yield.Even linseed oil, which contains high amounts of linolic and linolenic acid, can be used as starting material, after conversion into the methyl esters by methanolysis.Byproducts of the ozonolysis can be oxidized to the corresponding carboxylic acids which are valuable intermediates in oleochemistry.
- Mittelbach, Martin,Poklukar, Norbert
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p. 331 - 332
(2007/10/02)
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- SYNTHESIS OF 1,3-DIOLS: ITS APPLICATION TO THE SYNTHESIS OF α-LIPOIC ACID
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1,3-diols have been prepared from monosubstitited olefins, and the utility of this method in the synthesis of α-lipoic acid has been described.
- Rao, A. V. Rama,Mysorekar, Sudha V.,Yadav, J. S.
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p. 1339 - 1348
(2007/10/02)
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- Synthesis of 2-(6-Methoxycarbonylhexyl)cyclopent-2-en-1-one through Acylation Reactions of γ-Butyrolactone.
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Methyl 9,12-dioxododecanoate is prepared by a synthetic sequence which relies on the reaction of the chloride of nonanedioic acid monomethyl ester with the lithium, bromozinc or, more conveniently, α-C,O-disilyl enol derivative of γ-butyrolactone.Selective hydrolysis, followed by spontaneous decarboxylation, with disodium hydrogen phosphate in boiling water-dioxane then gives methyl 12-hydroxy-9-oxododecanoate, which is oxidised with buffered pyridinium chlorochromate to methyl 9,12-dioxododecanoate, a known precursor of 2-(6-methoxycarbonylhexyl)cyclopent-2-en-1-one and a prostaglandin intermediate.
- Boga, Carla,Savoia, Diego,Trombini, Claudio,Umani-Ronchi, Achille
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p. 2461 - 2472
(2007/10/02)
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