25231-38-3Relevant academic research and scientific papers
Reaction pathways at the initial steps of trioxane polymerisation
Hoffmann, Matthias,Bizzarri, Claudia,Leitner, Walter,Müller, Thomas E.
, p. 5594 - 5603 (2018)
Cleavage and (re)formation of oxymethylene moieties are essential steps during the build-up of polyoxymethylene (POM), a technically relevant high-performance polymer. To reveal how the catalyst accomplishes the cleavage of oxymethylene moieties, the kinetics of the ring-opening of trioxane was studied. Thereby insights into the initial phase of the growth of oxymethylene chains were obtained. The chain length of short oligomers was controlled with acetic anhydride as transfer agent. With a high ratio of acetic anhydride to trioxane, the first homologues of the series, trioxymethylene diacetate, dioxymethylene diacetate and monooxymethylene diacetate were obtained in excellent yield. The homologues show distinct features in the NMR and IR spectra that were related to their reactivity during chain propagation. Formation of intermediate hemi-acetal oxonium moieties is suggested to be a key step in the reaction pathway. Such molecular level insight may be a crucial factor for further tailoring production and properties of polyoxymethylene as well as introducing oligomeric oxymethylene diacetates to new application fields.
Observation of bromomethyl ethers during the bromomethylation of aromatic compounds
St. Clair, Jerry D.,Valentine, James R.
, p. 1013 - 1014 (2005)
A literature method claiming to avoid the generation of highly toxic intermediates during bromomethylation of aromatic compounds was investigated. Gas chromatography revealed that such toxic intermediates may be present in the reaction mass in significant concentration. Indeed, these intermediates can be the major components under certain reaction scenarios. It is thus inaccurate to consider this chemistry free of hazardous intermediates. These potential hazards should be considered in any laboratory or scale-up implementation of this chemistry.
Method for preparing ether compound
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Paragraph 0076; 0077, (2016/10/07)
An ether compound represented by a formula (3) (wherein R represents alkyl having 1 to 6 carbon atoms) can be prepared by the following method. The method comprises the steps: step A, a compound (wherein n represents 0-5 of integer, X represents halogen a
Process for preparing 1,1-disubstituted ethylenic monomers
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Paragraph 0079, (2015/11/16)
The present invention relates to a process for preparing 1,1-disubstituted ethylene monomers having general formula (I) from a compound of general formula (II) and an active methylene compound of general formula (III) using a catalytic amount of an ammonium or iminium salt in homogeneous phase or supported on a solid substrate. Said process allows the direct synthesis of the monomers and finds application in the preparation of a wide variety of monomers. The products obtained are reactive monomers of high purity which find application in the field of fast curing adhesives.
PROCESS FOR PREPARING V- TI-P CATALYSTS FOR SYNTHESIS OF 2,3-UNSATURATED CARBOXYLIC ACIDS
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Paragraph 000245, (2014/10/15)
The invention relates to a catalyst composition comprising a mixed oxide of vanadium, titanium, and phosphorus. The titanium component is derived from a water-soluble, redox-active organo-titanium compound. The catalyst composition is highly effective at facilitating the vapor-phase condensation of formaldehyde with acetic acid to generate acrylic acid, particularly using an industrially relevant aqueous liquid feed. Additionally, the catalyst composition is catalytically active towards the formation of acrylic acid from methylene diacetate and methacrylic acid from methylene dipropionate; both reactions are carried out with high space time yields.
HYDROCARBOXYLATION OF METHYLENE DIPROPIONATE IN THE PRESENCE OF PROPIONIC ACID AND A HETEROGENEOUS CATALYST
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Paragraph 0122, (2013/10/08)
Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of methylene dipropionate in the presence of a solid acid catalyst and propionic acid. This invention discloses hydrocarboxylations and corresponding glycolic acid separations wherein the propionic acid stream is readily removed from the glycolic acid and the propionic acid is recycled.
HYDROCARBOXYLATION OF FORMALDEHYDE IN THE PRESENCE OF A HIGHER ORDER CARBOXYLIC ACID AND HETEROGENEOUS CATALYST
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Paragraph 0128, (2013/10/08)
Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of formaldehyde in the presence of a solid acid catalyst and a carboxylic acid. This invention discloses hydrocarboxylations and corresponding glycolic acid separations wherein the glycolic acid stream is readily removed from the carboxylic acid and the carboxylic acid is recycled.
HYDROCARBOXYLATION OF METHYLENE DIPROPIONATE IN THE PRESENCE OF A PROPIONIC ACID AND A HOMOGENEOUS CATALYST
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Paragraph 0142, (2013/10/08)
Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of methylene dipropionate in the presence of a homogeneous acid catalyst and propionic acid. This invention discloses hydrocarboxylations and corresponding homogeneous acid catalyst and glycolic acid separations. The homogeneous acid catalyst is readily separated from the hydrocarboxylation reaction effluent and recycled and the propionic acid is readily removed from the glycolic acid and the propionic acid is recycled
HYDROCARBOXYLATION OF FORMALDEHYDE IN THE PRESENCE OF A HIGHER ORDER CARBOXYLIC ACID AND A HOMOGENEOUS CATALYST
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Paragraph 0133, (2013/10/08)
Disclosed is a process for the production and purification of glycolic acid or glycolic acid derivatives by the carbonylation of formaldehyde in the presence of a homogeneous acid catalyst and a carboxylic acid. This invention discloses hydrocarboxylations and corresponding homogeneous acid catalyst and glycolic acid separations. The homogeneous acid catalyst is readily separated from the hydrocarboxylation reaction effluent and recycled and the carboxylic acid is readily removed from the glycolic acid and the carboxylic acid is recycled.
Process for preparing esters and organic halides
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Page/Page column 5-7, (2013/02/27)
A process for preparing esters and organic halides, which comprises reacting - a salt having a melting point of less than 100°C (at 1 bar) and of the formula ???????? (K+)n X (COO-)n, in which K+ is an organic cation, X (COO-)n is an organic anion having an n-valent organic group X which is substituted by n carboxylate groups COO-, and n is 1, 2 or 3, - with an organic halogen compound (Hal)mY, in which Hal is a halogen atom, Y is an m-valent organic group, and m is 1, 2 or 3, to give an ester and a halide K+ Hal-.
