- Alkylating potential of oxetanes
-
Small, highly strained heterocycles are archetypical alkylating agents (oxiranes, β-lactones, aziridinium, and thiirinium ions). Oxetanes, which are tetragonal ethers, are higher homologues of oxiranes and reduced counterparts of β-lactones, and would therefore be expected to be active alkylating agents. Oxetanes are widely used in the manufacture of polymers, especially in organic light-emitting diodes (OLEDs), and are present, as a substructure, in compounds such as the widely used antimitotic taxol. Whereas the results of animal tests suggest that trimethylene oxide (TMO), the parent compound, and β,β-dimethyloxetane (DMOX) are active carcinogens at the site of injection, no studies have explored the alkylating ability and genotoxicity of oxetanes. This work addresses the issue using a mixed methodology: a kinetic study of the alkylation reaction of 4-(p-nitrobenzyl) pyridine (NBP), a trap for alkylating agents with nucleophilicity similar to that of DNA bases, by three oxetanes (TMO, DMOX, and methyloxetanemethanol), and a mutagenicity, genotoxicity, and cell viability study (Salmonella microsome test, BTC E. coli test, alkaline comet assay, and MTT assay). The results suggest either that oxetanes lack genotoxic capacity or that their mode of action is very different from that of epoxides and β-lactones.
- Gomez-Bombarelli, Rafael,Palma, Bernardo Brito,Martins, Celia,Kranendonk, Michel,Rodrigues, Antonio S.,Calle, Emilio,Rueff, Jose,Casado, Julio
-
-
Read Online
- A strategy for generating alkyl radicals from aliphatic esters and lactones via sequential hydrolysis and photoinduced decarboxylation
-
Sequential hydrolysis and photoinduced decarboxylation of methyl aliphatic esters lead to efficient generation of alkyl radicals under mild conditions. The generated alkyl radicals react with a variety of reagents to produce addition, reduction, and substitution products. In addition, the new tin and halogen free process for alkyl radical generation is applicable to a variety of aliphatic esters including those of dipeptides, steroids, saccharides, and lactones.
- Saito, Hikaru,Kanetake, Takayuki,Osaka, Kazuyuki,Maeda, Kousuke,Morita, Toshio,Yoshimi, Yasuharu
-
-
Read Online
- Identification and Counting of Carbonyl and Hydroxyl Functionalities in Protonated Bifunctional Analytes by Using Solution Derivatization Prior to Mass Spectrometric Analysis Via Ion-Molecule Reactions
-
A mass spectrometric method has been developed for the identification of carbonyl and hydroxyl functional groups, as well as for counting the functional groups, in previously unknown protonated bifunctional oxygen-containing analytes. This method utilizes solution reduction before mass spectrometric analysis to convert the carbonyl groups to hydroxyl groups. Gas-phase ion-molecule reactions of the protonated reduced analytes with neutral trimethylborate (TMB) in a FT-ICR mass spectrometer give diagnostic product ions. The reaction sequence likely involves three consecutive steps, proton abstraction from the protonated analyte by TMB, addition of the neutral analyte to the boron reagent, and elimination of a neutral methanol molecule. The number of methanol molecules eliminated upon reactions with TMB reveals the number of hydroxyl groups in the analyte. Comparison of the reactions of the original and reduced analytes reveals the presence and number of carbonyl and hydroxyl groups in the analyte.
- Somuramasami, Jayalakshmi,Winger, Brian E.,Gillespie, Todd A.,Kenttaemaa, Hilkka I.
-
-
Read Online
- An Efficient Deprotection of 2,6-Bis(trifluoromethyl)phenylboronic Esters via Catalytic Protodeboronation Using Tetrabutyl ammonium Fluoride
-
We herein describe an efficient deprotection of 2,6-bis(trifluoromethyl)phenylboronic esters, which serve as effective protective groups for 1,2- or 1,3-diols in various organic transformations, via protodeboronation by using a catalytic amount of tetrabutylammonium fluoride (TBAF).
- Makino, Kazuishi,Nojima, Shinya,Shimada, Naoyuki,Urata, Sari
-
-
Read Online
- Method for producing a shaped catalyst body
-
Provided herein is a novel process for producing shaped catalyst bodies in which a mixture having aluminum contents of Al±0 in the range from 80 to 99.8% by weight, based on the mixture used, is used to form a specific intermetallic phase, shaped catalyst bodies obtainable by the process of the invention, a process for producing an active catalyst fixed bed including the shaped catalyst bodies provided herein, the active catalyst fixed beds and also the use of these active catalyst fixed beds for the hydrogenation of organic hydrogenatable compounds or for formate degradation.
- -
-
Page/Page column 29-32
(2021/11/19)
-
- Preparation method of hydroxypivalaldehyde and application of hydroxypivalaldehyde in preparation of neopentyl glycol
-
The invention provides a preparation method of 2,2-dimethyl-3-hydroxypropanal and application thereof in preparation of neopentyl glycol. The 2,2-dimethyl-3-hydroxypropanal is prepared from an epoxy compound by a hydroformylation method. The method has the advantages of good atom economy, low raw material cost, no wastewater generation, and high yield. The invention also provides the application of the 2,2-dimethyl-3-hydroxypropanal in preparation of the neopentyl glycol. The application method circumvents the disadvantages of the conventional methods in the prior art, the reaction system is simple, and the industrial application prospect is excellent.
- -
-
Paragraph 0039; 0042-0044; 0047-0049; 0052-0053
(2021/02/09)
-
- Protodeboronation of (Hetero)Arylboronic Esters: Direct versus Prehydrolytic Pathways and Self-/Auto-Catalysis
-
The kinetics and mechanism of the base-catalyzed hydrolysis (ArB(OR)2→ ArB(OH)2) and protodeboronation (ArB(OR)2→ ArH) of a series of boronic esters, encompassing eight different polyols and 10 polyfluoroaryl and heteroaryl moieties, have been investigated by in situ and stopped-flow NMR spectroscopy (19F,1H, and11B), pH-rate dependence, isotope entrainment,2H KIEs, and KS-DFT computations. The study reveals the phenomenological stability of boronic esters under basic aqueous-organic conditions to be highly nuanced. In contrast to common assumption, esterification does not necessarily impart greater stability compared to the corresponding boronic acid. Moreover, hydrolysis of the ester to the boronic acid can be a dominant component of the overall protodeboronation process, augmented by self-, auto-, and oxidative (phenolic) catalysis when the pH is close to the pKaof the boronic acid/ester.
- Hayes, Hannah L. D.,Wei, Ran,Assante, Michele,Geogheghan, Katherine J.,Jin, Na,Tomasi, Simone,Noonan, Gary,Leach, Andrew G.,Lloyd-Jones, Guy C.
-
supporting information
p. 14814 - 14826
(2021/09/13)
-
- Photo-Induced ortho-C-H Borylation of Arenes through in Situ Generation of Rhodium(II) Ate Complexes
-
Photoinduced in situ "oxidation"of half-sandwich metal complexes to "high-valent"cationic metal complexes has been used to accelerate catalytic reactions. Here, we report the unprecedented photoinduced in situ "reduction"of half-sandwich metal [Rh(III)] complexes to "low-valent"anionic metal [Rh(II)] ate complexes, which facilitate ligand exchange with electron-deficient elements (diboron). This strategy was realized by using a functionalized cyclopentadienyl (CpA3) Rh(III) catalyst we developed, which enabled the basic group-directed room temperature ortho-C-H borylation of arenes.
- Araujo Dias, Ant?nio Junio,Nagashima, Yuki,Tanaka, Jin,Tanaka, Ken
-
supporting information
p. 11325 - 11331
(2021/08/03)
-
- Method For The Combined Production of Polyols In The Presence Of An Inorganic Base
-
The present invention relates to a process for simultaneously consecutive preparation of polyols by base-catalysed reaction of at least two different mid-chain aldehydes with formaldehyde. The simultaneous consecutive mode of operation makes it possible to achieve high conversions and high selectivities for both aldehydes, with additional achievement of a distinct reduction in the amount of unreacted formaldehyde remaining. This leads to improved process economics, since the energy costs for workup of the formaldehyde stream are distinctly reduced.
- -
-
Paragraph 0054; 0055
(2019/08/20)
-
- A phenol valeric acid neopentyl glycol monoester and neopentyl glycol production preparation method
-
The invention discloses a phenol valeric acid neopentyl glycol monoester and neopentyl glycol production of the preparation method, the isobutyl aldehyde and formaldehyde solution under the action of the alkaline catalyst, generating the aldol reaction, disproportionation reaction and [...] (Tischenkoreaction) reaction to produce the phenol valeric acid neopentyl glycol monoester and neopentyl glycol-based mixture, then and in (soluble alkali as catalyst) or filter (to solid alkali as catalyst) to remove the catalyst, rectifying and separating, to respectively obtain the NPG and phenol valeric acid neopentyl glycol monoester. The invention phenol valeric acid neopentyl glycol monoester and neopentyl glycol production preparation method, adopt one-pot condensation process at the same time to obtain high purity phenol valeric acid neopentyl glycol monoester and neopentyl glycol, simple technology, equipment investment, separating is simple, is easy to be popularized.
- -
-
Paragraph 0039; 0040; 0041; 0042; 0043; 0044
(2019/03/23)
-
- Preparation method of neopentyl glycol
-
The invention discloses a preparation method of neopentyl glycol. The preparation method comprises the following steps of using iso-butyraldehyde and formaldehyde as raw materials, using calcium hydroxide and triethylamine as composite catalysts, and performing condensation reaction at the temperature of 30 to 50 DEG C and the pressure of 0.5 to 1.2 MPa; after reaction is finished, adding formic acid to adjust the pH (potential of hydrogen) value to be 8 to 9, then filtering to obtain filtrate, adding formic acid to adjust the pH value to be 6 to 7, so as to obtain a hydroxyl valeraldehyde solution; adding methanol and a catalyst into the hydroxyl valeraldehyde solution, and performing hydrogenation reaction, so as to obtain a neopentyl glycol solution; respectively extracting the neopentyl glycol solution by a mixed solution of petroleum ether and dichloromethane, so as to obtain a crude product of neopentyl glycol; then performing reduced pressure distillation, gasifying, and condensing, so as to obtain the neopentyl glycol. The preparation method provided by the invention has the advantages that the preparation method is simple, the production amount of wastewater is small, thepollution to environment is little, and the purity of the product is high.
- -
-
Paragraph 0034; 0037; 0038; 0041; 0042; 0044
(2019/02/21)
-
- Method for continuously producing neopentyl glycol
-
The invention discloses a method for continuously producing neopentyl glycol. The method comprises the following steps: performing a condensation reaction on isobutyraldehyde and formaldehyde under the catalysis of tertiary alkylamine to obtain hydroxypivalaldehyde (HPA); condensing the HPA into a mixed hydroxylpivalic neopentyl glycol monoester (HPNE) liquid through a Tishchenko reaction under the action of an alkali catalyst in a fixed-bed reactor; continuously adding the synthesized mixed HPNE liquid into a loop reactor containing a hydrogenation catalyst and an NPG solution for a hydrogenation reaction, separating a reaction product by using a cross-flow filter, refluxing a circulating liquid containing the catalyst into the loop reactor, and rectifying a clear liquid to obtain the neopentyl glycol (NPG). According to the continuous production method of the neopentyl glycol, the HPA is basically converted into the more stable HPNE, cyclic hydrogenation is performed by using the loop reactor, and byproduct production is reduced, therefore, the product quality is improved and the product yield is increased; by the method, the stable operation of a continuous industrial productiontechnology and a continuous industrial production device of the neopentyl glycol can be guaranteed.
- -
-
Paragraph 0028; 0029; 0030; 0031; 0034; 0035; 0036; 0037
(2018/11/22)
-
- Carbohydrate/DBU Cocatalyzed Alkene Diboration: Mechanistic Insight Provides Enhanced Catalytic Efficiency and Substrate Scope
-
A mechanistic investigation of the carbohydrate/DBU cocatalyzed enantioselective diboration of alkenes is presented. These studies provide an understanding of the origin of stereoselectivity and also reveal a strategy for enhancing reactivity and broadening the substrate scope.
- Yan, Lu,Meng, Yan,Haeffner, Fredrik,Leon, Robert M.,Crockett, Michael P.,Morken, James P.
-
supporting information
p. 3663 - 3673
(2018/03/21)
-
- Catalytic Hydrogenation of Cyclic Carbonates using Manganese Complexes
-
Catalytic hydrogenation of cyclic carbonates to diols and methanol was achieved using a molecular catalyst based on earth-abundant manganese. The complex [Mn(CO)2(Br)[HN(C2H4PiPr2)2] 1 comprising commercially available MACHO ligand is an effective pre-catalyst operating under relatively mild conditions (T=120 °C, p(H2)=30–60 bar). Upon activation with NaOtBu, the formation of coordinatively unsaturated complex [Mn(CO)2[N(C2H4PiPr2)2)] 5 was spectroscopically verified, which confirmed a kinetically competent intermediate. With the pre-activated complex, turnover numbers up to 620 and 400 were achieved for the formation of the diol and methanol, respectively. Stoichiometric reactions under catalytically relevant conditions provide insight into the stepwise reduction form the CO2 level in carbonates to methanol as final product.
- Kaithal, Akash,H?lscher, Markus,Leitner, Walter
-
supporting information
p. 13449 - 13453
(2018/09/25)
-
- PREPARATION METHOD OF NEOPENTYL GLYCOL
-
The present invention relates to a method capable of producing a neopentyl glycol having a high purity while minimizing by-products in a shorter time by further simplifying a reaction process to increase the efficiency and economy of the reaction, wherein the method for producing the neopentyl glycol comprises a step for reducing dimethyl malonic acid in the presence of a metal catalyst fixed to a silica support and containing a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) compound in a weight ratio of 1:0.8 to 1.2:1.2 to 2.4.COPYRIGHT KIPO 2018
- -
-
Paragraph 0070-0072; 0093-0102
(2018/05/15)
-
- METHOD FOR PREPARING NEOPENTYL GLYCOL
-
The method for manufacturing substrates provided such as neopentyl glycol, more particularly copper based catalyst fixed bed gasification reactor comprising reacting hydrogen hydroxypivaldehyde solution such as neopentyl glycol in a method of manufacturing a hydrogen is put in the hydrogenation, the hydrogenation pressure 20 to 50barg, 0 WHSV (weight hourly space velocity). 2 to 0. 9hr-1 , reunion yield 0. 1 to 8. 0 kg/kg, and moisture content 0. 1 to 18% by weight carried out in conditions characterized of neopentyl glycol are disclosed. According to the substrate, hydrogenation reactor pressure, WHSV, yield and moisture reunion silica, 2, 2, 4 - trimethyl - 1, 3 - pentanediol discharged reactor such as neopentyl glycol solution (TMPD) is 0. 15% by weight of included below high purity such as neopentyl glycol 2000 is prevented. (by machine translation)
- -
-
Paragraph 0005; 0086; 0087; 0112
(2017/08/18)
-
- HIGHLY EFFICIENT NEOPENTYL GLYCOL PREPARATION METHOD AND DEVICE THEREFOR
-
Disclosed are a highly efficient neopentyl glycol preparation method and a device therefor. More particularly, disclosed are a method of preparing neopentyl glycol, wherein the method includes adding a hydroxypivaldehyde solution and hydrogen to a hydrogenation reactor that including a hydrogenation catalyst, wherein the hydroxypivaldehyde solution includes 6 to 30% by weight of hydroxypivaldehyde, to 70% by weight of neopentyl glycol, 10 to 30% by weight of alcohol, and 10 to 30% by weight of water, and a device therefor. According to the present disclosure, a neopentyl glycol preparation method wherein separate heating is not required in a section of a feed vessel to an inlet of a hydrogenation reactor unlike conventional technologies to save energy, and, at the same time, by-products with a high boiling point are not generated in the section to prevent poisoning of a hydrogenation catalyst in a reactor due to the by-products with a high boiling point and increase a hydrogenation yield, and a device therefor can be provided.
- -
-
Paragraph 0052; 0060
(2016/09/12)
-
- Npg condensation hydrogenation apparatus and process for producing
-
The invention discloses a neopentyl glycol condensation hydrogenation production process which comprises the following steps of: 1) condensation, that is, performing a condensation reaction of isobutyraldehyde with a methanol aqueous solution of formaldehyde, delivering the mixed condensation products into a condensation circulation tower for separation, allowing hydroxypivalaldehyde to enter a hydrogenation reactor from the condensation circulation tower, allowing a gas-phase component to flow back to a raw material mixing zone for mixing, and to enter a condensation reactor; 2) hydrogenation, that is, performing a hydrogenation reaction of the hydroxypivalaldehyde with hydrogen, delivering the products into a gas-liquid separation tank, allowing a gas-phase component to flow back to the hydrogenation reactor, allowing the liquid-phase neopentyl glycol crude product to enter a saponification reactor; 3) refining, that is, performing a saponification reaction of the neopentyl glycol crude product, allowing the product to enter a low-boiling-point substance fractionating tower, allowing a liquid-phase component at the tower bottom to enter a flash tank, allowing a liquid-phase component at the flash tank bottom to enter a pH adjusting tank, adjusting the pH to 6.5-7, allowing the product to enter a falling film evaporator, allowing a gas-phase component at the top of the falling film evaporator to enter a drying tower, then to enter a rectifying tower for refining so as to obtain neopentyl glycol. The process of the invention is high in neopentyl glycol yield, and simple and effective in separation purification process.
- -
-
Paragraph 0061-0064
(2017/03/17)
-
- MANUFACTURING EQUIPMENT FOR PREPARING NEOPENTYL GLYCOL HAVING HIGH PROCESS EFFICIENCY
-
The present disclosure relates to an apparatus for producing neopentyl glycol with high processing efficiency. More particularly, the present disclosure relates to an apparatus for producing neopentyl glycol with high processing efficiency, which comprises: a hydrogenation reactor including a hydrogenation catalyst therein; a material feed line for supplying hydroxypivaldehyde solution to the hydrogenation reactor; a discharge line for discharging a neopentyl glycol product produced from the hydrogenation reactor; and a recycling line for recycling a part of the discharged neopentyl glycol product to the hydrogenation reactor, wherein a pre-heater is installed in the material feed line, and a circulator and a heat exchanger are installed in the discharge line. According to the apparatus for producing neopentyl glycol with high processing efficiency of the present disclosure, it is possible to prevent clogging of the lines to solve the time- and system-related troubles. It is possible to increase productivity, since there is no clogging of the lines and shut-down of the apparatus. There is no need for carrying out line cleaning even when the apparatus is operated again after shut-down for a predetermined time. It is possible to make continuous flow with no additional driving power, thereby avoiding a need for input of additional energy, or to make continuous flow merely by using a small amount of hydrogen extracted from a hydrogen feed line without significant modification of the existing lines, thereby providing high cost-efficiency.COPYRIGHT KIPO 2016
- -
-
Paragraph 0093; 0094; 0095; 0096
(2017/03/23)
-
- Method for preparing Neophentylglycol
-
The present invention relates to a method for preparing neophentylglycol(2,2,-dimethyl-1,3-dihydroxypropane). The present invention doesn′t use high-pressure hydrogen gas like an existing technology when hydrogenation reaction to prepare neophentylglycol, but uses a secondary alcohol generating hydrogen ions in reaction as a reaction solvent, thereby progressing the hydrogenation reaction effectively. The present invention suggests plans to solve problems of increase in risk caused by using high-pressure hydrogen gas and cost increasing factors to prepare and manage all related manufacturing devices for high pressure.
- -
-
Paragraph 0036; 0037
(2017/06/19)
-
- A Stereoselective Synthesis of Lentiginosine
-
A concise stereoselective synthesis of (-)-lentiginosine, an iminosugar endowed with an interesting proapoptotic activity, has been accomplished using an enantiopure pyrroline N-oxide building block derived from d-tartaric acid. Key steps are a totally diastereoselective nucleophilic addition to the cyclic nitrone followed by a combination of two simultaneous and two tandem reactions occurring under the same conditions in a single laboratory operation. Natural (+)-lentiginosine can be synthesized by the same method but starting from l-tartaric acid. (Chemical Equation Presented).
- Cordero, Franca M.,Vurchio, Carolina,Brandi, Alberto
-
p. 1661 - 1664
(2016/03/01)
-
- Continuous Method for the Production of Neopentyl Glycol
-
A continuous method for preparing neopentyl glycol by addition of isobutyraldehyde and formaldehyde in the presence of a tertiary alkylamine as catalyst to give hydroxypivalaldehyde with subsequent hydrogenation in the gas phase at a temperature of 125 to 180° C., is characterised in that the hydrogenation is carried out in the presence of a copper chromite catalyst comprising the activators barium and manganese and at a superatmospheric pressure of 30 to 120 kPa.
- -
-
Paragraph 0041-0062
(2015/09/22)
-
- Method for the Production of Neopentyl Glycol
-
A method for preparing neopentyl glycol by addition of isobutyraldehyde and formaldehyde in the presence of a tertiary alkylamine as catalyst to give hydroxypivalaldehyde with subsequent hydrogenation at a temperature of 80 to 140° C. and at a pressure of 2 to 18 MPa in the liquid phase, is characterized in that the hydrogenation is carried out in the presence of a copper chromite catalyst comprising the activators barium and manganese.
- -
-
Paragraph 0055; 0056
(2015/09/23)
-
- Process for producing polyols
-
A process for producing polyols (such as neopentyl glycol) is disclosed which comprises reacting formaldehyde and another aldehyde in the presence of a trialkylamine catalyst and a base promoter to form an Aldol condensation reaction product. The base promoter improves removal of nitrogen containing salts prior to hydrogenation of the hydroxy aldehyde to produce the polyol. The improved process also reduces trialkylamine catalyst usage, improves trialkylamine catalyst recovery, and reduces nitrogen-containing salts prior to hydrogenation.
- -
-
Page/Page column 6
(2014/05/08)
-
- 9-AMINOMETHYL SUBSTITUTED TETRACYCLINE COMPOUNDS
-
The present invention relates to 9-aminomethyl substituted tetracycline compounds represented by formula (I), or pharmaceutically acceptable salt, prodrug, solvate or isomer thereof, as well as a method for preparing these compounds and a pharmaceutical composition comprising the same. The present invention relates also to a use of these compounds in the preparation of a medicament for the treatment and/or prophylaxis of tetracycline drug-sensitive disease. wherein, R2a, R2b, R3, R4a, R4b, R5, R6a, R6b, R7, R8, R9a, R9b, R10, R11, R12, R13a and R13b are each independently as defined in the description.
- -
-
Page/Page column
(2014/07/08)
-
- 9-AMINOMETHYL SUBSTITUTED TETRACYCLINE COMPOUND
-
The present invention relates to 9-aminomethyl substituted tetracycline compounds represented by formula (I), or pharmaceutically acceptable salt, prodrug, solvate or isomer thereof, as well as a method for preparing these compounds and a pharmaceutical composition comprising the same. The present invention relates also to a use of these compounds in the preparation of a medicament for the treatment and/or prophylaxis of tetracycline drug-sensitive disease. wherein, R2a, R2b, R3, R4a, R4b, R5, R6a, R6b, R7, R8, R9a, R9b, R10, R11, R12, R13a and R13b are each independently as defined in the description.
- -
-
Paragraph 0082-0083
(2014/06/24)
-
- PROCESS FOR PREPARING NEOPENTYL GLYCOL
-
A process for distilling an aqueous NPG mixture comprising NPG, a tertiary amine, water and the adduct of tertiary amine and formic acid (amine formate), said distillation being performed in a distillation column, which comprises drawing off a gaseous stream in the upper region of the column and feeding it to two condensers connected in series, the first condenser being operated in such a way that a portion of the gaseous stream is condensed in the first condenser and the second condenser being operated in such a way that the uncondensed portion of the gaseous stream is essentially fully condensed in the second condenser, the condensed stream from the first condenser being recycled fully or partly as reflux into the column.
- -
-
Paragraph 0187; 0188; 0189; 0190; 0191; 0192; 0193
(2013/03/26)
-
- METHOD FOR PREPARING POLYMETHYLOLS
-
The present invention relates to a process for distilling an aqueous polymethylol mixture which comprises a polymethylol of the formula (I) [in-line-formulae](HOCH2)2—C—R2??(I)[/in-line-formulae] in which each R is independently a further methylol group or an alkyl group having 1 to 22 carbon atoms or an aryl or aralkyl group having 6 to 22 carbon atoms, a tertiary amine, water and the adduct of tertiary amine and formic acid (amine formate), which comprises performing the distillation in a distillation column which is connected at the bottom to an evaporator, the bottom temperature being above the evaporation temperature of the monoester of formic acid and polymethylol (polymethylol formate) which forms during distillation. The present invention further relates to a composition comprising polymethylol and 1 to 10 000 ppm by weight of polymethylol formate, and to the use thereof.
- -
-
Page/Page column 8
(2012/01/14)
-
- 5,5-dimethyl-1,3-dioxan-4-ol as orthogonally protected equivalent of 2,2-dimethyl-3-hydroxypropanal
-
Condensation of isobutyraldehyde with aqueous formaldehyde in the presence of Ba(OH)2 gave a new gem-dimethyl-substituted building block.
- Yagafarov,Valeev,Bikzhanov,Iginasheva,Miftakhov
-
p. 820 - 822
(2012/11/13)
-
- METHOD OF PRODUCING NEOPENTYL GLYCOL
-
The present invention relates to a method of producing neopentyl glycol by addition of isobutyraldehyde and formaldehyde in the presence of a tertiary alkylamine as catalyst to give the hydroxypivalinaldehyde with subsequent liquid phase hydrogenation in the presence of a nickel catalyst at a temperature of 80 to 180° C. and at a pressure of 6 to 18 MPa in the presence of an aliphatic alcohol and in the presence of water.
- -
-
Page/Page column 3-4
(2011/05/05)
-
- PROCESS FOR PREPARING NEOPENTYL GLYCOL
-
The present invention relates to a process for preparing neopentyl glycol (NPG) by continuously hydrogenating hydroxypivalaldehyde (HPA) with hydrogen, in the liquid phase, in the presence of a hydrogenation catalyst, in a hydrogenation reactor (5), by combining an HPA-comprising stream (1) with an NPG-comprising stream (2) to give a hydrogenation feed (4) and introducing the hydrogenation feed (4) into the hydrogenation reactor (5) and additionally supplying at least one pH regulator (3) selected from the group consisting of tertiary amine, an inorganic base, an inorganic acid and an organic acid to the HPA-comprising stream (1) or the NPG-comprising stream (2) or the hydrogenation feed (4), in order to establish a pH of 7.0 to 9.0 at the outlet of the hydrogenation reactor, wherein the weight ratio of HPA to NPG in the hydrogenation feed (4) is in the range from 1:100 to 50:100 and the proportion of HPA and NPG in the hydrogenation feed (4) is at least 50% by weight, based on the hydrogenation feed, and, in the case that the pH regulator (3) is supplied to the HPA-comprising stream (1), the HPA-comprising stream (1) comprises less than 50% by weight of HPA or the residence time between the supply of the pH regulator (3) and the combining of the NPG-comprising stream (2) with the HPA-comprising stream (1) is less than 5 minutes or the temperature of the HPA-comprising stream (1) is less than 75° C.
- -
-
Page/Page column 6
(2011/11/30)
-
- METHOD FOR PRODUCING HYDROXY PIVALIN ALDEHYDE AND NEOPENTYL GLYCOL
-
The preparation of hydroxypivalaldehyde is effected by aldolizing isobutyraldehyde with formaldehyde and subsequently working up the resulting reaction effluent by distillation, wherein the reaction effluent is fed to a distillation column which is operated at a top pressure in the range from 0.5 to 1.5 bar and in which a two-stage condensation is provided in the top region, in which the vapors are first conducted into a partial condenser operated at a temperature in the range from 50 to 80° C., whose condensate is recycled at least partly into the distillation column, and in which the vapors uncondensed in the partial condenser are fed to a downstream condenser operated at a temperature in the range from ?40 to +30° C., whose condensate is at least partly discharged.
- -
-
Page/Page column 2-3
(2010/05/13)
-
- PROCESS FOR HYDROGENATING METHYLOLALKANALS
-
A process for catalytically hydrogenating methylolalkanals of the general formula in which R1 and R2 are each independently a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 33 carbon atoms, in the liquid phase over a hydrogenation catalyst, which comprises setting a pH of from 7.0 to 9.0 in the hydrogenation effluent by adding at least one tertiary amine, an inorganic base or an inorganic or organic acid to the hydrogenation feed.
- -
-
Page/Page column 3
(2009/04/24)
-
- PROCESS FOR THE PRODUCTION OF NEOPENTYLGLYCOL USING FORMALDEHYDE WITH A LOW METHANOL CONTENT
-
A process is provided for the preparation of polymethylol compounds of formula (I): [in-line-formulae](HOCH2)2—C—(R)2 , ??(I)[/in-line-formulae] in which the radicals R independently of one another are each a further methylol group, an alkyl group having from 1 to 22 C atoms or an aryl or aralkyl group having from 6 to 22 C atoms, by (a) condensing aldehydes having from 2 to 24 C atoms with formaldehyde in an aldol reaction using tertiary amines as a catalyst to give alkanals of formula (II): in which the radicals R independently of one another are each as defined above, (b) then separating, by distillation, the reaction mixture obtained into a bottom product comprising predominantly the compounds of formula II and a low-boiling stream consisting of unconverted or partially converted starting materials, and (c) hydrogenating the distillation bottom, wherein the aldol reaction is carried out with an aqueous formaldehyde solution having a methanol content of 0.35 to 0.5% by weight of methanol, the low-boiling stream is separated off at a pressure of 1 to 3 bar and temperatures of 100 to 135° C. and completely or partially recycled into the aldol reaction. This procedure advantageously makes it possible specifically to prevent the formation of by-products and hence to increase the yield of the desired polymethylol compound. We have found that this object is achieved by a process for the preparation of polymethylol compounds of formula (I): [in-line-formulae](HOCH2)2—C—(R)2 , ??(I)[/in-line-formulae] in which the radicals R independently of one another are each a further methylol group, an alkyl group having from 1 to 22 C atoms or an aryl or aralkyl group having from 6 to 22 C atoms, by (a) condensing aldehydes having from 2 to 24 C atoms with formaldehyde in an aldol reaction using tertiary amines as a catalyst to give alkanals of formula (II): in which the radicals R independently of one another are each as defined above, (b) then separating, by distillation, the reaction mixture obtained (aldolization product) into a bottom product comprising predominantly the compounds of formula II and a low-boiling stream consisting of unconverted or partially converted starting materials, and (c) hydrogenating the distillation bottom, wherein the aldol reaction is carried out with an aqueous formaldehyde solution having a methanol content of 0.35 to 0.5% by weight, the separation of the low-boiling stream is effected at a pressure of 1.1 to 3 bar, preferably 1.5 bar, and a temperature of 100 to 135° C., preferably of 102 to 125° C., and the low-boiling stream is completely or partially recycled into the aldol reaction, preferably the entire low-boiling stream being recycled. In the aldol reaction, a partially converted starting compound of formula (III): can also be formed in which the radicals R independently of one another are each hydrogen or are as defined above. According to the invention, this partially converted starting compound of formula (III), together with the desired alkanal of formula (II), is separated from the other by-products and the unreacted starting compounds and reacted again in an aldol reaction with formaldehyde having a methanol content of 0.35% by weight to 0.5% by weight, using tertiary amines as a catalyst.
- -
-
Page/Page column 4
(2008/06/13)
-
- PROCESS FOR PREPARING POLYALCOHOLS FROM FORMALDEHYDE HAVING A LOW FORMIC ACID CONTENT
-
The invention relates to a process for preparing polymethylol compounds of the formula (I) [in-line-formulae](HOCH2)2—C—R2 ??(I)[/in-line-formulae] where the radicals R are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 22 carbon atoms, by condensation of aldehydes having from 2 to 24 carbon atoms with formaldehyde in an aldol reaction using tertiary amines as catalyst to form alkanals of the formula (II) where the radicals R each independently have one of the abovementioned meanings, and subsequent hydrogenation of the latter. The particular inventive feature of this process is that the aldol reaction is carried out using an aqueous formaldehyde solution having a formic acid content of 150 ppm and preferably 100 ppm. In this way of carrying out the process, the formation of by-products can advantageously be prevented in a targeted manner and the yield of the desired polymethylol compound can thereby be increased.
- -
-
Page/Page column 4
(2008/12/06)
-
- Photolabile protection of 1,2- and 1,3-diols with salicylaldehyde derivatives
-
(Chemical Equation Presented) 1,2- and 1,3-diols, including carbohydrates, can be readily caged as acetals of 5-methoxy- or 5-hydroxysalicylaldehydes. Irradiation of these acetals with 300 nm light results in their efficient (Φ = 0.2-0.3) cleavage, regenerating an aldehyde and a glycol in excellent chemical yield. Photoreactive 5-hydroxysalicylaldehyde acetals can be produced by mild in situ reduction of photostable p-quinone precursors.
- Kostikov, Alexey P.,Popik, Vladimir V.
-
scheme or table
p. 5277 - 5280
(2009/06/18)
-
- PROCESS FOR PRODUCING POTASSIUM FORMATE
-
The present invention relates to a process for producing potassium formate. Formaldehyde, potassium hydroxide and isobutyraldehyde are reacted in water, at a molar ratio of 1.0:1.0:1.0 to 3.0:2.0:1.0 and at a temperature of 0-1000C, preferably 30-700C. The obtained reaction solution is neutralised to pH 4-6 and evaporated in a first step, whereby two phases are obtained, one organic phase and one aqueous phase, the latter comprising the main part of the potassium formate. The organic phase is subsequently separated from the aqueous phase, where after a final evaporation of the aqueous phase takes place at a pressure of 0.0-1.0 bar and a temperature of 160-2500C, to obtain a melt of potassium formate. Water is added followed by filtration resulting in a solution having a content of >99% by weight of potassium formate, calculated on a water free basis.
- -
-
Page/Page column 2-3
(2008/12/07)
-
- Hydrogenation of methylolalkanals
-
Process for the catalytic hydrogenation of methylolalkanals of the general formula where R1 and R2 are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 33 carbon atoms, in the liquid phase by means of hydrogen over a hydrogenation catalyst, wherein hydrogen is used in a molar ratio to methylolalkanal of greater than 1.
- -
-
Page/Page column 3
(2008/06/13)
-
- Process of producing dioxane glycol
-
A production method of 2-(5-ethyl-5-hydroxymethyl-1,3-dioxane-2-yl)-2-methylpropane-1-ol (DOG) which includes a step of acetalizing hydroxypivalaldehyde with trimethylolpropane in a solvent in the presence of an acid catalyst. After the acetalization, the reaction product liquid is neutralized and then heated to dissolve the deposited DOG crystals. Then, the reaction product liquid is cooled to recrystallize DOG. DOG produced in such manner has an adequately large particle size. Therefore, DOG is easy to handle and involves little danger of dust explosion.
- -
-
Page/Page column 4
(2008/06/13)
-
- Process of producing dioxane glycol
-
A process of producing 2-(5-ethyl-5-hydroxymethyl-1,3-dioxane-2-yl)-2-methylpropane-1-ol (DOG) by the acetalization of hydroxypivalaldehyde with trimethylolpropane in water in the presence of an acid catalyst and optional seed crystals. DOG crystals having an increased particle size and containing the trans isomer in a high content are produced by the process in which the reaction temperature, pH of the reaction system and concentration of DOG to be produced in the reaction system are controlled.
- -
-
Page/Page column 5
(2008/06/13)
-
- Method of producing high-purity hydroxypivalaldehyde and/or dimer thereof
-
The present invention provides a method of producing high-purity hydroxypivalaldehyde and/or dimer thereof, including: reacting isobutyl aldehyde with formaldehyde in a presence of a basic catalyst; distilling a low boiling point component including unreacted isobutyl aldehyde to obtain an aqueous solution; adding a diluent to the aqueous solution; cooling the aqueous solution to crystallize the hydroxypivalaldehyde and/or the dimer thereof; and subjecting the aqueous solution to a solid-liquid separation, followed by washing with an organic solvent and/or water, in which the diluent and a basic compound are added to the aqueous solution containing the hydroxypivalaldehyde and/or the dimer thereof obtained by distilling the low boiling point component off so that a concentration of the hydroxypivalaldehyde and/or the dimer becomes 5 to 23% by mass, the concentration of formaldehyde becomes 0.2 to 2.5% by mass, and a pH value becomes 5.0 or more, the solution is crystallized at a temperature of 20 to 45° C. and subjected to the solid-liquid separation. In this method, handling of a high-viscosity slurry and carrying out any complicated operation such as regeneration of an ion exchange resin are not required, so the high-purity HPA and/or the dimer thereof can be obtained in high yield with an energetically advantageous manner.
- -
-
Page/Page column 4; 6; 7
(2008/06/13)
-
- Synthesis and fugicidal activities of 2-silatranyl propylamino-4-substitued phenyl(hydrogen)-5,5-dimethyl-1,3,2-dioxaphosphinanes-2-oxides (sulfides)
-
Phosphoryl-aminopropyl-silatranes 4 were synthesized by nucleophilic reactions of 2-Cl-1,3,2- dioxaphosphinanes 2 with α-aminopropyl-silatrane 3, which was obtained by the cyclization reaction of triethanolamine and γ-aminopropyltriethoxysilane. The structures of the products were characterized by 1H NMR, 31P NMR, IR, MS, and elemental analyses. The target compounds 4 exhibited fungicidal activity. Copyright Taylor & Francis Inc.
- Wan, Shi-Guan,Yang, Xing-Yu,Yu, Yan,Liu, Chang
-
p. 2813 - 2821
(2007/10/03)
-
- Process for the production of the spiroglycol 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane
-
In the production of spiroglycol by the reaction of pentaerythritol and hydroxypivalaldehyde in water in the presence of an acid catalyst, (A) a total content of amines and amine salts in hydroxypivalaldehyde is reduced to 1.5% by weight or lower; (B) seed crystals are added to the reaction system before initiating the reaction and/or during the reaction in an amount from 1.5 to 30% by weight on the basis of the total feed amount of pentaerythritol, hydroxypivalaldehyde, water, the acid catalyst and the seed crystals, each being fed into the reaction system; (C) the pH of the reaction system is kept from 0.1 to 4.0 from initiation of the reaction to completion of the reaction; and (D) the sum of a maximum theoretical amount of spiroglycol to be synthesized from pentaerythritol and hydroxypivalaldehyde to be fed into the reaction system and an amount of spiroglycol contained in the seed crystals to be added to the reaction system is controlled within a range from 5 to 35% by weight on the basis of the total feed amount. The spiroglycol produced has an increased particle size. By washing the spiroglycol with a basic solution, the heat stability is improved.
- -
-
Page/Page column 5
(2008/06/13)
-
- Stabilized hydroxypivalaldehyde
-
In the method of the invention, hydroxypivalaldehyde (3-hydroxy-2,2-dimethylpropanal) and/or its dimer is stored under solid conditions containing an amount of water. By storing such solid conditions, hydroxypivalaldehyde and/or its dimer is stored for a long period of time without reducing its purity.
- -
-
Page/Page column 5
(2008/06/13)
-
- Asymmetric synthesis of (3S,4R,7S)-(-)-3-hydroxy-7-methoxy-2,2,4-trimethyl- decanoic acid, a plausible polyketide fragment of halipeptin A
-
The first enantioselective synthesis of (3S,4R,7S)-(-)-3-hydroxy-7-methoxy- 2,2,4-trimethyl-decanoic acid 4 in 11 steps and 6% overall yield, starting from commercially available methyl 2,2-dimethyl-3-hydroxy propionate 5 is described. The stereochemical flexible synthetic pathway involves a Brown's crotylboration reaction and a Corey-Bakshi-Shibata (CBS) oxazaborolidine-mediated reduction.
- Della Monica, Carmela,Maulucci, Nakia,De Riccardis, Francesco,Izzo, Irene
-
p. 3371 - 3378
(2007/10/03)
-
- A new strategy for the enantioselective synthesis of carba-prostacyclin analogues based on organocopper conjugate addition to a bicyclic azoene and its application to the synthesis of 13,14-dinor-inter-p-phenylene carbacyclin
-
An enantioselective synthesis of E/Z-13,14-dinor-inter-p-phenylene carbacyclin (E/Z-2d) by a new strategy has been realized that holds the prospect of serving as a general route for carba-prostacyclin analogues. The key intermediate in this synthesis is the bicyclic azoene Ts-9, and the key step is the regio- and stereoselective conjugate addition of the chiral arylcopper compound Cu-8d/P-n-Bu3 to the azoene with formation of hydrazone 7d. Enantioselective synthesis of azoene Ts-9 of 95% ee from ketone 4 was accomplished in four and five steps, respectively. Thus, enantioselective deprotonation of bicyclic ketone 4 with chiral base Li-10 and trapping of lithium enolate 11 with CISiMe3 gave enol ether 12, which was chlorinated with N-chlorosuccinimide (NCS) to afford chloro ketone 13. Alternatively, chloro ketone 13 was also prepared upon chlorination of 11 with NCS. Chloro ketone 13 was converted to chloro hydrazone 14, which upon treatment with a mild base furnished azoene Ts-9. Arylcopper compound 8d of 98% ee was obtained in two steps from alcohol 16, which was prepared by enantioselective reduction of ketone 17 with (-)-diisopinocampheylchloroborane. Carbacyclin derivative E/Z-2d was found to be essentially inactive as an inhibitor of ADP induced human platelet aggregation, having an |C50 of > 10 μmol/L.
- Van Bergen, Marc,Gais, Hans-Joachim
-
p. 4321 - 4328
(2007/10/03)
-
- Monoalcoholates of 1,3-diols as effective catalysts in the Tishchenko esterification of 1,3-dioxan-4-ols
-
Alkali metal monoalcoholates of 1,3-diols can be used as very effective catalysts in the Tishchenko reaction of 4-hydroxy-1,3-dioxanes to the corresponding monoesters of 1,3-diols. These catalysts are extremely efficient and fast compared to metal hydroxides commonly used. Thus, monoalcoholate catalysts give fast transesterification with the product ester. The loss in yield due to ester interchange can be minimized by using a suitable 1,3-diol moiety in the catalyst.
- T?rm?kangas, Olli P.,Koskinen, Ari M.P.
-
p. 2743 - 2746
(2007/10/03)
-
- Carboxylic acids and derivatives thereof and pharmaceutical compositions containing them
-
The present invention relates to a novel class of compounds for treating hyperlipidemia, obesity and impaired glucose tolerance/noninsulin dependent diabetes mellitus without adversely affecting energy metabolism, and pharmaceutical compositions comprising the aforementioned compounds for the treatment of obesity, hyperlipidemia and maturity-onset diabetes.
- -
-
-
- Cosmetic and dermatological compositions containing a plasticizing oligomer and a film-forming polymer and uses thereof
-
A composition comprising at least one film forming polymer and at least one oligomer chosen from homopolymers or copolymers of monomers containing ethylenic unsaturation and polycondensates, having an average molecular weight, measured at the peak height by steric exclusion chromatography, ranging from 400 to 10,000 and having a glass transition temperature ranging from -80 to 10° C., the composition containing no film-forming polymer of the nitrocellulose type is disclosed. Topical formulations formulated from this composition, in particular hair compositions for styling, holding and/or fixing the hair, and make-up compositions are also disclosed.
- -
-
-
- Tethered α-boryl radical cyclizations of haloalkyl boronates
-
Boroalkyl radicals readily cyclize onto alkenyl and alkynyl traps tethered via a C-B-O linkage. Oxidative cleavage of the C-B bond of the temporary connection following cyclization affords 1,3-diols in good yields.
- Batey, Robert A.,Smil, David V.
-
p. 9183 - 9187
(2007/10/03)
-