摘要:
A carboxylic acid ester is prepared by a process comprising: reacting an aldehyde and an alcohol in a liquid phase in the presence of molecular oxygen as indicated by the following reaction: RCHO+R′OH+O2→RCOOR′+H2O in the presence of a catalyst comprising at least palladium and an element X, wherein X is bismuth, lead or a combination thereof, supported on a carrier, wherein the catalyst has an acid strength, pKa, of more than 4.8 and shows an ammonia chemical adsorption amount at 0° C. of 0-150 &mgr;mol/g-catalyst.
摘要:
There are provided a dihalogen derivative represented by formula (2): wherein X represents a halogen atom and R2 represents a protective group for a hydroxyl group; a process for producing the same; and a process for producing vitamin A by use of said dihalogen derivative.
摘要:
A process for the oxidation of a C2 to C4 alkane to produce the corresponding alkene and carboxylic acid which process comprises contacting in an oxidation reaction zone, said alkane, molecular oxygen-containing gas, and optionally, at least one of the corresponding alkene and water, in the presence of at least two catalysts each active, with different selectivities, for the oxidation of the alkane to the corresponding alkene and carboxylic acid, to produce a product stream comprising said alkene, carboxylic acid and water, and in which process the molar ratio of alkene to carboxylic acid produced in said oxidation reaction zone is adjusted or maintained at a pre-determined value by controlling the relative proportions of the at least two catalysts in said oxidation reaction zone. Such an oxidation process may be used in an integrated process, such as for the manufacture of ethyl acetate or vinyl acetate.
摘要:
A catalyst for the bisalkoxycarbonylation of olefins comprising a noble metal compound and a phosphine chalcogenide of the following formula (1): wherein each of R1, R2 and R3 is, independently, an alkyl group or an aryl group each of which may have a substituent, and A is a Group 16 element of the Periodic Table; and R1, R2 or R3 may be combined, directly or through a bridging group, with one another where the groups to be combined may be attached either to an identical phosphorus atom or to different phosphorus atoms. Element A includes oxygen, sulfur and selenium atoms. The noble metal compound includes palladium(II) halides and other palladium compounds. The catalyst may further include a copper(I) halide or other copper compound as a co-catalyst. The use of this catalyst can provide the bisalkoxycarbonylation of olefins with efficiency.
摘要:
Methanol is reacted in presence of catalyst system comprising of an iron containing compound and a tin containing compound with or without an organic compound containing C, N, O, P, S, diamine, diketone, and or diphosphines as a ligand to produce acetic acid or methyl acetate. The reaction is effected in a solvent containing nitro or nitrite group.
摘要:
The present invention relates to a process of recovering monomeric esters of substituted or unsubstituted acrylic acid from polymer material having corresponding structural units by depolymerization by means of a fine-grained heat-transfer medium which is maintained above the depolymerization temperature of the polymer material. In a reactor, the polymer material is brought in contact with hot, mechanically fluidized heat-transfer medium. The resulting vapors are withdrawn and condensed, where the hot heat-transfer medium is continuously supplied at one end of the reactor, and cooled heat-transfer medium is discharged at the other end.
摘要:
A catalyst for use in the production of vinyl acetate which comprises (1) a catalyst support, (2) palladium, (3) an acid, (4) at least one acetic acid catalyst promoter and (5) at least one vinyl acetate promoter and/or co-promoter. A process for the production of vinyl acetate from ethylene and an oxygen-containing gas using the catalyst.
摘要:
A process for producing a 2-aralkyl-3-hydroxypropionic acid (or its ester), comprising the steps of: reacting a 3-hydroxy-2-methylene-3-arylpropionic acid ester, easily obtained by the reaction of an arylaldehyde with an acrylic acid ester, with an acid anhydride to form a 2-aralkylidene-3-acyloxypropionic acid ester; subjecting the same to hydrolysis or alcoholysis; and reducing the resulting 2-aralkylidene-3-hydroxypropionic acid or its ester. The reduction step may be conducted in the presence of a base.
摘要:
The invention is a base-modified clay that selectively catalyzes the formation of a glycol monoester from an aldehyde. The base-modified clay comprises a clay having secluded conjugate base sites and exchangeable interstitial cationic spaces. In the base-modified clay, the interstitial hydroxyl groups have been converted to oxide sites, at least one structural hydroxyl group has been converted to an oxide site. The base-modified clay contains sufficient conjugate base cations to balance the charge of said oxide groups. Processes for preparing the base-modified clay are described. The invention also provides a process for preparing a glycol monoester. This process includes heating in a reaction vessel an aldehyde and a catalytic amount of the base-modified clay under conditions sufficient to produce a glycol monoester.