Abstract: A process and a preparation plant prepares methacrolein from formaldehyde and propionaldehyde, in presence of water and a homogeneous catalyst based at least on an acid and a base. A reaction mixture is introduced into a methacrolein workup plant and separated in a first distillation column, into a first distillation mixture in a gas phase at the top and a second distillation mixture in a liquid phase at the bottom. The first distillation mixture is condensed and, in a first phase separator, the organic phase and the aqueous phase of the condensate are separated from one another. The aqueous phase is introduced into a second distillation column, that is not part of the methacrolein workup plant, and is separated into a third distillation mixture in a gas phase at the top and a fourth distillation mixture at the bottom. The third distillation mixture is introduced into the methacrolein workup plant.

Abstract: The present invention relates to an optimized process for preparing methacrylic acid, wherein methacrolein is prepared in a first stage from propionaldehyde and formaldehyde by means of a Mannich reaction and oxidized in a second stage to methacrylic acid. More particularly, the present invention relates to the reduction in the amounts of catalyst to be used in the first stage, especially to the reduction in the amounts of acid to be used here, by virtue of the additional installation of recycling streams suitable for the purpose.

Abstract: The present invention relates to the oxidative combustion of amine-containing wastewaters, especially in a process for preparing methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for preparation of methacrylic acid, methyl methacrylate, or else of active ingredients, odorants or flavorings. More particularly, the present invention relates to an oxidative combustion of the amine-containing wastewaters with only low nitrogen oxide formation.

Abstract: There is provided a novel intermediate for producing pesticides. A method for producing the compound of Formula (3) comprises reacting an aromatic ketone compound of Formula (4) and a substituted acetophenone compound of Formula (5) as starting raw materials in an organic solvent or water in the presence or absence of an additive in the presence of a base in a suspended state. A method may comprise dehydrating the compound of Formula (3). A method for producing compound (2) in one step comprises reacting compound (4) and compound (5) to obtain compound (3). Further, a method for producing an isoxazoline compound of Formula (1) comprises reacting compound (2) and a hydroxylamine in an aliphatic or an aromatic hydrocarbon solvent which is optionally substituted by a halogen atom by adding an additive selected from a phase-transfer catalyst, a C1-C6 alcohol and an aprotic polar solvent in the presence of a base and water.

Abstract: The invention relates to a continuous method for carrying out a multiphase aldol condensation reaction to obtain mixed ?,?-unsaturated aldehydes by reacting a mixture of two aliphatic aldehydes having different numbers of carbon atoms, i.e. 2 to 5, in the molecule in a vertical tubular reactor in a concurrent flow in the presence of an aqueous solution of a basically reacting compound. In said method, the aldehyde mixture is dispersed in the aqueous phase in the form of drops, and the aqueous solution of the basically reacting compound flows through the tubular reactor as a continuous phase in laminar conditions.

Abstract: Disclosed is a process for the production of higher aldehydes from lower alcohols using a two-stage vapor phase heterogeneous catalyst system. Ethanol feeds afford aldehydes such as butyraldehyde and crotonaldehyde while butanol feeds yield 2-ethylhexanal and 2-ethylhexenal. Higher product selectivities are obtained when the alcohol is first dehydrogenated in the upper catalyst stage followed by aldol condensation of the resulting lower aldehyde to a higher aldehyde.

Abstract: The present invention relates to a process for synthesizing acrolein, coupling the dehydration of glycerol into acrolein with a reaction for aldol condensation of acetaldehyde, produced in the form of an impurity during the dehydration, by means of formaldehyde.

Abstract: The invention relates to a continuous method for carrying out a multiphase aldol condensation reaction to obtain mixed ?, ?-unsaturated aldehydes by reacting a mixture of two aliphatic aldehydes having different numbers of carbon atoms, i.e. 2 to 5, in the molecule in a vertical tubular reactor in a concurrent flow in the presence of an aqueous solution of a basically reacting compound. In said method, the aldehyde mixture is dispersed in the aqueous phase in the form of drops, and the aqueous solution of the basically reacting compound flows through the tubular reactor as a continuous phase in laminar conditions.

Abstract: The invention relates to a method for continuously producing ?,?-unsaturated C10-aldehydes from aliphatic C5-aldehydes, comprising the following steps: aldol-condensing aliphatic C5-aldehydes into ?,?-unsaturated C10-aldehydes in the presence of an aqueous base in a tube reactor; phase separating the output of the tube reactor into an aqueous catalyst phase and an organic product phase; separating the organic product phase into ?,?-unsaturated C10-aldehydes, aliphatic C5-aldehydes, and auxiliary products; discharging a part of the aqueous catalyst phase to remove the reaction water and supplementing said part with liquor solution and subsequently returning said part to the tube reactor. The task of the invention is to improve a method of said kind in a way such that it requires lower energy input. This is achieved in that the aliphatic C5-aldehydes and/or the ?,?-unsaturated C10-aldehydes are dispersed in the aqueous base as drops, wherein the average Sauter diameter of the drops is between 0.2 mm and 2 mm.

Abstract: The invention relates to a method for producing ?,?-unsaturated aldehydes, wherein a catalytic aldol condensation of charged aldehydes is carried out in the presence of an aqueous base within a continuous-flow reactor. The aim of the invention is to provide a method for aldolizing aldehydes that can be carried out in a particularly economical manner. The aim is achieved by using a reaction mixing pump as the reactor.

Abstract: The present invention relates to a process for synthesizing acrolein, coupling the dehydration of glycerol into acrolein with a reaction for aldol condensation of acetaldehyde, produced in the form of an impurity during the dehydration, by means of formaldehyde.

Abstract: The invention relates to a method for producing ?,?-unsaturated aldehydes, wherein a catalytic aldol condensation of charged aldehydes is carried out in the presence of an aqueous base within a continuous-flow reactor. The aim of the invention is to provide a method for aldolizing aldehydes that can be carried out in a particularly economical manner. The aim is achieved by using a reaction mixing pump as the reactor.

Abstract: A method for producing a mixture of ethylene and carbon monoxide by contacting ethane and an oxygen source with a catalyst comprising synthetic cryptomelane or octahedral molecular sieve. The method further comprises condensing the alkyl propionate with formaldehyde to produce an alkyl methacrylate.

Abstract: The present invention relates to processes for producing ?,?-unsaturated aldehyde compounds and unsaturated alcohols with a good yield. There is provided a process for producing and ?,?-unsaturated aldehyde compound including the step of subjecting a raw aldehyde compound to an intermolecular condensation reaction in the presence of an amine and a protonic acid having 4 to 20 carbon atoms or a salt thereof; and a process for producing an unsaturated alcohol including the step of subjecting the ?,?-unsaturated aldehyde compound to a reduction reaction.

Abstract: Methods for preparing self-aldol condensation products of prenyl aldehyde (3-methyl-2-butenal) by use of an amine catalyst under weakly acidic conditions at temperatures of 10° C. or higher are disclosed. Methods are disclosed for the selective formation of ?-1,2-adducts and ?-1,2-adducts of prenyl aldehyde, and for the formation of specialty compositions useful in the flavor and fragrance industries.

Abstract: An industrial process for producing hydroxyaldehydes efficiently, by solving the problems of conventional DERA, such as low stability against aldehydes, low catalytic activity for aldol condensation, and the difficulty of controlling the number of acetaldehyde molecules to be condensed, is provided. According to the process, aldol condensation of a substituted or unsubstituted aliphatic aldehyde compound having 2 to 6 carbon atoms with acetaldehyde is conducted by using D-2-deoxyribose-5-phosphate aldolase which is highly stable against aldehydes and has high catalytic activity for aldol condensation, whereby a hydroxyaldehyde compound having the number of carbon atoms increased by two or four can be produced.

Abstract: 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.

Abstract: The present invention provides a process for producing an ?,?-bis(hydroxymethyl)alkanal represented by Formula (II): (wherein R represents an alkyl group, a cycloalkyl group, or an aryl group) which comprises reacting an aldehyde represented by Formula (I): R—CH2—CHO ??(I) (wherein R has the same meaning as defined above) with formaldehyde in the presence of a basic catalyst and a phase-transfer catalyst.

Abstract: The present invention provides an improved process for the synthesis of ?-substituted acroleins from olefins by a tandem hydroformylation and Mannich reaction sequence in the presence of syngas and formaldehyde, wherein the two catalysts are segregated into two different phases thereby preventing deactivation of the catalysts by each other, and yielding a highly selective and active catalyst.

Abstract: The invention relates to 2-methyl-4-ethyl-2-octene-1-aldehyde of formula (I), which is characterized by interesting and original odor characteristics which diffuse extremely well. The inventive substance is suitable for use as fragrance, for example in cosmetic preparations, technical products or in alcoholic perfumery.

Abstract: Production of unsaturated aldehydes by the aldol condensation of straight chain aldehydes, e.g. butyraldehyde, by contacting the aldehyde in the vapour phase with a particulate catalyst comprising at least one basic alkali metal compound supported on an inert substrate at a temperature above 175° C.

Abstract: Aldehydes are prepared in a hydroformylation apparatus by the multiphase hydroformylation reaction of one or more olefins with hydrogen and carbon monoxide, where the continuous phase contains a solvent mixture and the hydroformylation catalyst is present in the continuous phase, at least one olefin is present in the dispersed phase, and the loading factor of the tube reactor is greater than or equal to 0.8.

Abstract: A process for preparing aldols by catalytic reaction of aldehydes and/or ketones comprises conducting said reaction in the channels of a microstructured reaction system.

Abstract: &agr;,&bgr;-Unsaturated keto compounds are prepared by base-catalyzed aldol condensation of aldehydes and/or ketones having from 1 to 15 carbon atoms, comprising: reacting the aldehydes and/or ketones with an aqueous catalyst solution under adiabatic reaction conditions; and separating the reaction mixture obtained by rapid distillation into a top product comprising water, aldehyde and/or ketone and a bottom product comprising &agr;,&bgr;-unsaturated keto compounds and aqueous catalyst phase.

Abstract: A process for preparing 1,3-diols having 6 or more carbon atoms comprises a) provision of at least one alkanal having at least three carbon atoms; b) thermal treatment of the alkanal in the absence of a basic catalyst; c) hydrogenation of the aldol addition product formed in step b); and d) isolation of the 1,3-diol obtained. The process of the present invention makes it possible to prepare 1,3-diols simply and inexpensively.

Abstract: The invention relates to a process for the catalytic aldol condensation of aldehydes by means of a multiphase reaction in a tube reactor, wherein the catalyst is present in the continuous phase and at least one aldehyde is present in a dispersed phase and the loading factor B of the tube reactor is equal to or greater than 0.8; the aldol condensation products obtained in this way can be used for preparing alcohols or carboxylic acids.

Abstract: The present invention relates to a process for producing 2,2'-bis(hydroxymethyl)alkanal and 2,2'-bis(hydroxymethyl)alkanoic acid as raw materials for dimethylol alkanoic acids or trimethylol alkanes, which are useful for the production of polyesters, polyurethanes, alkyd resins and the like, in an industrially advantageous manner.

Abstract: The present invention relates to a modified Raney nickel catalyst which can serves as hydrogenation catalyst for hydroxy aldehydes, such as 4-hydroxy-butanal, and 2-methyl-3-hydroxypropanal and hydroxy cyclic ethers such as 2-hydroxy-tetrahydrofuran. Further, a process for preparing diols by using the modified Raney nickel catalyst is provided.

Abstract: The invention relates to a new, technically simple but efficient process, with a good yield, for the preparation of 2-ethyl-1,3-hexane diol from n-butyraldehyde by aldol condensation in the presence of an alkali metal hydroxide or alkali earth metal hydroxide catalyst. To promote the reaction and to improve its controllability, a neutral phase-transfer catalyst is additionally used in the process according to the invention. 2-Ethyl-1,3-hexane diol is used in insecticides and, for example, in the preparation of polyesters.

Abstract: An aldolisation-dehydration process is disclosed for converting an aldehyde, e.g. n-valeraldehyde, to a substituted acrolein, e.g. propyl butyl acrolein (2-propylhept-2-enal). Aldolisation and dehydration are effected in a stirred tank reactor (16; 111) using an alkali catalyst, such as sodium hydroxide. A reaction product stream (23; 113) containing both organic and aqueous phases is distilled (in column 25; 123) to yield a heterogeneous azeotrope containing water and aldehyde. On condensation and phase separation the lower water layer (34; 150) can be discharged from the plant without the need for neutralisation. From the bottom of the distillation zone a mixture (36;157) of substituted acrolein and alkali catalyst solution is obtained. The substituted acrolein is recovered as product (45;173), while the catalyst solution (47;175) is recycled to the aldolisation reactor. Part (49; 181) of the catalyst solution is purged to control the level of Cannizzaro reaction products.

Abstract: A process for the catalytical preparation of condensation products of formaldehyde, in which formaldehyde or a formaldehyde-forming compound is caused to undergo reaction using a catalyst which has been produced, in the presence of an auxiliary base, from a triazolium salt of formula I ##STR1## in which R.sup.1 and R.sup.3 are the same or different and stand for aliphatic groups having from 1 to 30 carbon atoms, optionally substituted aryl groups, optionally substituted aralkyl groups, and/or optionally substituted heteroaryl groups,R.sup.2 represents hydrogen, the hydroxymethylene group --CH.sub.2 OH or the hydroxy-hydroxymethylene-methylidyne group --CH(OH)(CH.sub.2 OH), andR.sup.4 denotes hydrogen, a halogen atom, a nitro or cyano group, an aliphatic group having from 1 to 30 carbon atoms, an optionally substituted aryl group, an optionally substituted aralkyl group, an optionally substituted heteroaryl group, an alkoxy group --OR.sup.5, a thioether group --SR.sup.6, an amino group --NR.sup.7R R.sup.

Abstract: A process for producing dimeric unsaturated aldehydes from alpha, beta unsaturated aldehyde is disclosed. This process is conducted by contacting the alpha, beta unsaturated aldehyde with a copper (II) catalyst and a complexing amine catalyst in a medium with a relatively high dielectric constant in substantially anhydrous and aprotic conditions.

Abstract: Preparation of diethers of the formula ##STR1## wherein R is an alkyl, cycloalkyl, aryl, or aralkyl radical, by formation of an unsaturated aldehyde of the formula ##STR2## wherein R is as defined above, by means of an aldol condensation reaction, reduction of said aldehyde to form the corresponding saturated compound, transformation of the saturated compound into the corresponding diol, and consequent methylation of the diol into diether.

Abstract: A process for preparing 2-hexene-1,6-dial comprising dimerizing 2-propenal in the presence of an organometallic compound of the group VIII metal. The desired compound can be obtained under mild conditions with industrial advantages.

Abstract: Solid solutions of a class of divalent metal oxides and a class of trivalent metal oxides resulting from calcination of layered double hydroxides related to hydrotalcite have been prepared with a surface area in excess of 150 m.sup.2 /g. Such high surface area materials are found to be quite effective in the aldol condensation of aldehydes and ketones, and in particular in the conversion of n-butyraldehyde to 2-ethyl-2-hexenal in high yield and with good selectivity in a liquid phase reaction at temperatures under about 200.degree. C. Variants can be devised where the aldol condensation product, an .alpha.,.beta.-unsaturated aldehyde or ketone, is concurrently reduced to the saturated alcohol under process conditions.

Abstract: A process for the preparation of 4-acetals of butene-1,4-dial of the formula ##STR1## where R is an alkyl, alkenyl, cycloalkyl or aralkyl radical of 1 to 12 carbon atoms which may contain alkoxy groups, or the two radicals R together form an alkylene or alkenylene radical of 2 to 10 carbon atoms which may contain alkoxy groups, and R.sup.1 is an alkyl, alkenyl or alkynyl radical of 1 to 12 carbon atoms which may be substituted by cycloaliphatic, aromatic or heterocyclic radicals or by hydroxyl, ether, thioether, acyl, alkylamino, carboxyl or carbalkoxy groups, or is an unsubstituted or substituted aryl radical or an alkoxy, alkylthio or acyloxy group, wherein a glyoxal monoacetal of the formula ##STR2## is reacted with an aldehyde of the formulaR.sup.1 --CH.sub.2 --CHO IIIat up to 150.degree. C., and novel acetals of butene-1,4-dial.

Abstract: Basic mixed oxides useful for base catalyzed reactions such as the aldol condensation of acetone and also useful as catalyst supports are made by mixing an acid such as nitric acid or acetic acid with a pseudoboehmite to form a gel, adding magnesium oxide or hydroxide, in a ratio of magnesium to aluminum of about 1:1 to about 10:1, agitating and heating for about 1 to 24 hours, and subsequently drying and calcining. The resulting polymorphic magnesium-aluminum oxide composition is hightly effective in the aldol condensation of acetone to isophorone, and other base catalyzed reactions such as isomerization of olefins, aldol condensation of aldehydes.

Abstract: A process for the preparation of alpha-alkylacroleins from aldehydes and formaldehyde. The reaction takes place in the presence of a secondary amine and a carboxylic acid having up to 5 carbon atoms, and is performed in two stages so that, in the first stage, part of the carboxylic acid is added to the reaction mixture and, in the second stage, the remaining carboxylic acid is added.

Abstract: A process for producing neopentyl glycol is disclosed which comprises reacting isobutyraldehyde and formaldehyde in the presence of a trialkylamine catalyst to form a condensation reaction product comprising hydroxypivaldehyde, followed by hydrogenation of the hydroxypivaldehyde in a hydrogen gas sparged reactor in the presence of a Raney nickel catalyst. This process minimizes unwanted by-products, and does not have to be carried out under high pressure as do certain prior art methods.

Abstract: This process for the preparation of products of general formula (I): ##STR1## wherein either R.sub.1 and R.sub.2, which are identical, represent a --CHRR.sub.3 group, in which R and R.sub.3, which are identical or different, represent an alkyl, alkenyl or aralkyl group, or R.sub.1 and R.sub.2, which are identical, represent a --CH.sub.2 R group, in which R represents a hydrogen atom, an alkyl, alkenyl or aralkyl radical, or R.sub.1 and R.sub.2 together form a --CH.sub.2 --(CRR).sub.n --CHR-- radical, in which n represents 0 or 1 and R retains the meaning given previously, is characterized by reacting glyoxal in the presence of an acid catalyst with an excess of the corresponding alcohol of general formula (II) RR.sub.3 CHOH, (III) RCH.sub.2 OH or (IV) --(CRR).sub.n --CHROH, in which R, R.sub.3 and n retain the meaning given previously, then stopping the reaction as soon as the concentration of the desired monoacetal of general formula (I) decreases in the reaction medium in favor of bisacetal.

Abstract: The invention relates to a process for the preparation of 2,4-disubstituted-1,5-pentanediols from formaldehyde and at least one simple aldehyde of the formula RCH.sub.2 CHO. More particularly the invention relates to a reaction to produce a 2,4-disubstituted glutaraldehyde wherein the reactant mole ratio of aldehyde/formaldehyde is between 1 and 8. The reaction is carried out in the presence of a secondary amine or secondary amine salt catalyst and leads to higher yields of the 2,4-disubstituted glutaraldehyde. The invention also relates to the production of 2,4-disubstituted-1,5-pentanediols by hydrogenation of the 2,4-disubstituted glutaraldehydes.

Abstract: A process for preparing a catalyst composition wherein a Metal Hydrocarboxide I, such as aluminum secbutoxide, a Metal Hydrocarboxide II, such as zirconium butoxide, an acidic phosphorus-oxygen composition, such as phosphoric acid, and water, are reacted in the presence of a liquid organic medium, such as acetone, to form a catalyst precursor composition, which is then calcined to form the catalyst, is disclosed. The catalyst is useful for condensing carboxylic acids or their ester with aldehydes or acetals to synthesize .alpha. ,.beta.-ethylenically unsaturated acids or esters, such as methylmethacrylate.

Abstract: The invention relates to a method for removing n-butyraldehyde from gas streams. It is characterized by washing with dilute aqueous alkali in a mass transfer apparatus. According to the invention, n-butyraldehyde can be removed from gas streams in the proportion of >90%, with operation at 0.degree.-40.degree. C. in the absence of added solubilizing agents.

Abstract: Aldehydes can be condensed with ketones or aldehydes to produce higher aldehydes or ketones by contacting the materials to be condensed with a nonzeolitic molecular sieve. The condensation may be carried out in the presence of hydrogen to give as product a saturated aldehyde or ketone. The ketone and/or aldehyde may be generated in situ by dehydrogenation of an alcohol, and the hydrogen thus liberated used to effect hydrogenation of the immediate unsaturated product of the condensation, thereby producing as the final product a saturated aldehyde or ketone. The non-zeolitic molecular sieves can achieve improved conversion rates and selectivities as compared with conventional catalysts for the reaction.

Abstract: Described is a process for preparing natural benzaldehyde and acetaldehyde and compositions of matter containing natural benzaldehyde and acetaldehyde as well as products produced thereby and organoleptic utilities thereof, which process comprises the step of contacting with base naturally occurring cinnamaldehyde or a natural product rich in cinnemaldehyde such as Ceylon oil of cinnamon, Ceylon cinnamon bark, Saigon cinnamon bark, cassia oil, Ceylon cinnamon quills, Cinnamon leaf oil, oil of cinnamon Madagascar or the like according to the reaction: ##STR1## the reaction taking place in aqueous media and in the presence of a food grade or natural nonionic emulisifier, preferably a nonionic sorbitan derivative emulsifying agent and in the absence of any other reagents.

Abstract: Described is a process for preparing natural benzaldehyde and acetaldehyde and compositions of matter containing natural benzaldehyde and acetaldehyde as well as products produced thereby and organoleptic utilities therefor, which process comprises the step of contacting with base naturally occurring cinnamaldehyde or a natural product rich in cinnamaldehyde such as Ceylon oil of cinnamon, Ceylon cinnamon bark, Saigon cinnamon bark, cassia oil, Ceylon cinnamon quills, cinnamon leaf oil, oil of cinnamon Madagascar or the like according to the reaction: ##STR1## the reaction taking place in the absence of any other reagents except inert solvent.

Abstract: A process for preparing a catalyst composition wherein a Metal Hydrocarboxide I, such as aluminum secbutoxide, a Metal Hydrocarboxide II, such as silicon ethoxide, an acidic phosphorus-oxygen composition, such as phosphoric acid, and water, are reacted in the presence of a liquid organic medium, such as acetone, to form a catalyst precursor composition, which is then calcined to form the catalyst, is disclosed. The catalyst is useful for condensing carboxylic acids or their ester with aldehydes or acetals to synthesize .alpha., .beta.-ethylenically unsaturated acids or esters, such as methylmethacrylate.

Abstract: Catalyst composition and process are provided for the dimerization of acrylic compounds. An acrylic compound may be dimerized in the liquid phase by contacting an acrylic compound with a catalyst in the presence of hydrogen, at a pressure of least about 1 psi and a temperature of at least about 50.degree. C., wherein the catalyst comprises an organic polymer catalyst support, trivalent pendant atoms covalently bonded to the support, ruthenium complexed with said trivalent pendant atoms, and a second metal which is at least one of Pb and the Group VIII metals other than Ru and Pd and is disposed on the organic polymer catalyst support.

Abstract: A catalyst and a liquid phase process are provided for the dimerization of acrylic compounds. The process includes contacting an acrylic compound with the catalyst in the presence of hydrogen, wherein the catalyst comprises an inorganic oxide catalyst support, trivalent pendant atoms covalently bonded to the support and ruthenium complexed with said trivalent pendant atoms.

Abstract: .alpha.-Alkylacroleins are prepared by a process wherein an alkanal is reacted with formaldehyde in the presence of a secondary amine and in the presence or absence, of an acid, in the liquid phase, under superatmospheric pressure and at above 150.degree. C., for not more than 25 minutes.The .alpha.-alkylacroleins obtainable by the process are useful starting materials for dyes, drugs and pesticides.