como nucleofilo en el carbono del benzaldehído, realizando una reacción de condensación de Claisen-Schmidt (tipo de condensación aldolica cruzada). Particulares ○ Efectuar una condensación aldólica cruzada. ○ Obtener un producto de uso comercial. Diferencia entre una condensación aldólica cruzada y. Específicos Efectuar una condensación aldólica cruzada. Determinar el rendimiento de la reacción realizada y el punto fusión del producto obtenido.
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ES2235425T3 – Tucked to produce highly pure trimethylolpropane. – Google Patents
The basic catalyst is used in an amount of 1. In addition, formaldehyde remaining in TMP product is not the completely eliminated by a usual distillation. Recientemente, el TMP ha empezado a ser ampliamente utilizado y particularmente en el uso como materia prima para resinas curables con ultravioleta, presentando el TMP una pureza superior a la que antes se ha llegado a requerir.
Therefore, an object of the present invention to provide an industrially advantageous method for producing a highly pure TMP from a crude TMP obtained by a reaction between NBAL and formaldehyde in the presence of a basic catalyst in a two-phase condensation aldol and a subsequent crossed Cannizzaro reaction. The present invention has been accomplished based on this finding. In the present invention, before the subsequent heat treatment, a component of high boiling point and an inorganic salt, including the salt of residual formic acid obtained as a byproduct during the crossed Cannizzaro reaction, the TMP crude thus separated was previously removed.
The liquid reaction mixture from the two-stage process contains a formic acid salt formed during the crossed Cannizzaro reaction.
The final product quality is adversely affected by the remaining formaldehyde even in a small amount. A method of further purification is described in DD-A Purification of propylene oxide using an aqueous acetone extractive distillatin agent. The solvent may be used alone or in combination of two or more.
To minimize the occurrence of byproducts and increase selectivity of the objective TMP, preferred set the amount of the basic catalyst according to the reaction conditions. Ejemplo comparativo 4 Comparative Example 4. Method for producing highly pure trimethylolpropane. Ejemplo comparativo 3 Comparative Example 3.
The Japanese Patent Publication No.
A process for obtaining trimethylolpropane-enriched product streams from the secondary streams of trimethylolpropane. In condensacio present invention, as the load of distillation column is reduced, the distillation apparatus improved from the economic viewpoint with respect to the structure and operatively allowing it to produce a highly pure TMP advantageously in industrial scale.
Thus, a highly pure TMP has not been obtained with conventional distillation methods. Por tanto, se produce a escala industrial de manera ventajosa un TMP sumamente puro utilizable como materia prima para resinas curables con aldolics.
However, the cast detrimentally final TMP color was as high as After removing the component and high boiling inorganic aldoliica of crude TMP, the resultant TMP distillate is subjected to a heat treatment under acidic conditions.
File:Cuatro productos reacción aldólica – Wikimedia Commons
Method for producing a highly pure trimethylolpropane according to claim 1, wherein component removing high boiling point and the inorganic salt is carried out after deactivating sodium formate present in the crude trimethylolpropane, aldooica the deactivation is carried out by means of adding an acid to crude TMP in an amount 0. Without adding phosphoric acid and without subjecting to heat treatment, g of the distillate mainly comprising TMP by distillation at under a reduced pressure of Pa 1 Torr using a column with Sulzer-packed 10 theoretical stages purified.
The content of the remaining formaldehyde in the final TMP was 30 ppm. In the present invention, as described above, after first removing the inorganic salt cruzda as sodium formate, and the component of high boiling the crude TMP, the treated Condnesacion is subjected to heat treatment under acidic conditions.
For example, the two-phase process using sodium hydroxide is expressed by the following reaction scheme.
The aldol condensation and the subsequent crossed Cannizzaro cruzadz may be carried out in the condejsacion of water in an amount of 2 to 20 times by weight of NBAL. The gas chromatographic analysis showed that the purity of TMP obtained was TMP obtained by the reaction between NBAL and formaldehyde in the presence of basic catalyst in the two-stage process of the aldol condensation and the subsequent crossed Cannizzaro reaction contains the impurities hardly removable by distillation.
Condensação de Claisen
Sin embargo, de manera perjudicial el color fundido del TMP final fue tan elevado como The molar ratio of formaldehyde to be used in the method with NBAL cruzaa 3. Although the condensation products are decomposed by the heat treatment using excess amount of acid, a colored component from high boiling point, which is difficult to remove TMP by distillation component is formed. Ejemplo comparativo 2 Comparative Example 2.
The content of the condenscion formaldehyde in the final TMP was 1 ppm.
The first stage aldol condensation and the second stage crossed Cannizzaro reaction are usually conducted successively in adolica same reaction vessel, without differentiating from the operational point of view one another. The content of the remaining formaldehyde in the final TMP was 3 ppm.
Formaldehyde used in the present invention as starting material can be used as an aqueous solution or solid as paraformaldehyde.