- Monoalcoholates of 1,3-diols as effective catalysts in the Tishchenko esterification of 1,3-dioxan-4-ols
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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.
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- Method for continuously synthesizing neopentyl glycol monoester hydropivalicate by gas phase method
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The invention belongs to the field of organic chemistry, and particularly relates to a method for continuously synthesizing neopentyl glycol monoester hydropivalicate by a gas phase method. The methodcomprises the following specific steps: fixing a supported catalyst A on a filler layer of a reaction rectifying tower A, putting formaldehyde and isobutyraldehyde into the reaction rectifying towerA, carrying out heating, and carrying out reacting under catalysis of a catalyst A to generate hydroxyl pivalaldehyde; sending the hydroxyl pivalaldehyde generated in the rectifying tower A to a reaction rectifying tower B from a tower kettle to carry out a reaction to generate a neopentyl glycol monoester hydropivalicate crude product, wherein a supported catalyst B is fixed in the reaction rectifying tower B; and feeding the neopentyl glycol monoester hydropivalicate crude product generated in the rectifying tower B into the rectifying tower C from the tower bottom, carrying out rectification and purification, and extracting the neopentyl glycol monoester hydropivalicate from the tower top. The method improves the yield of the neopentyl glycol monoester hydropivalicate, reduces cost andis worthy of industrial promotion.
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Paragraph 0016-0018
(2019/11/28)
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- A phenol valeric acid neopentyl glycol monoester and neopentyl glycol production preparation method
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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.
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Paragraph 0039; 0040; 0041; 0042; 0043; 0044
(2019/03/23)
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- Process of producing dioxane glycol
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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.
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Page/Page column 4
(2008/06/13)
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- Process of producing dioxane glycol
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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.
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Page/Page column 5
(2008/06/13)
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- Method of producing high-purity hydroxypivalaldehyde and/or dimer thereof
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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.
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Page/Page column 4; 6; 7
(2008/06/13)
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- Process for the production of the spiroglycol 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane
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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.
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Page/Page column 5
(2008/06/13)
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- Stabilized hydroxypivalaldehyde
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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.
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Page/Page column 5
(2008/06/13)
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