Abstract: The present invention relates to a process for the catalytic aldol condensation of aldehydes, in particular for preparing ?,?-unsaturated aldehydes, in a multiphase reactor.

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: An improved process for preparing hydroxy aldehydes, such as hydroxypivaldehyde, is provided. Specifically, the process employs an alkaline additive for separating by-product amine salts from a hydroxy aldehyde and other reaction products formed in the process of preparing a hydroxy aldehyde using an amine catalyst.

Abstract: The present invention relates to a process for the catalytic aldol condensation of aldehydes, in particular for preparing ?,?-unsaturated aldehydes, in a multiphase reactor.

Abstract: The invention relates to a method of producing optically active 4-chloro-3-hydroxybutanal compound (2) by reacting chloroacetaldehyde with aldehyde compound (1) in the presence of optically active pyrrolidine compound (5). wherein each symbol is as defined in the specification.

Abstract: The present invention relates to a process for preparing hydroxypivalaldehyde (HPA), which comprises in a first stage reacting isobutyraldehyde with formaldehyde in the presence of a tertiary amine and in a second stage introducing the reaction output obtained from the first stage into a stripping column. The present application further relates to a process for preparing neopentyl glycol (NPG) by hydrogenating the hydroxypivalaldehyde prepared in accordance with the invention and the further conversion of the NPG thus obtained to polyester resins, unsaturated polyester resins, lubricants or plasticizers.

Abstract: The preparation of hydroxypivalaldehyde is effected by aldolizing isobutyraldehyde with formaldehyde and subsequently working up the resulting reaction effluent by distillation, wherein the reaction effluent is fed to a distillation column which is operated at a top pressure in the range from 0.5 to 1.5 bar and in which a two-stage condensation is provided in the top region, in which the vapors are first conducted into a partial condenser operated at a temperature in the range from 50 to 80° C., whose condensate is recycled at least partly into the distillation column, and in which the vapors uncondensed in the partial condenser are fed to a downstream condenser operated at a temperature in the range from ?40 to +30° C., whose condensate is at least partly discharged.

Abstract: The preparation of hydroxypivalaldehyde is effected by aldolizing isobutyraldehyde with formaldehyde and subsequently working up the resulting reaction effluent by distillation, wherein the reaction effluent is fed to a distillation column which is operated at a top pressure in the range from 0.5 to 1.5 bar and in which a two-stage condensation is provided in the top region, in which the vapors are first conducted into a partial condenser operated at a temperature in the range from 50 to 80° C., whose condensate is recycled at least partly into the distillation column, and in which the vapors uncondensed in the partial condenser are fed to a downstream condenser operated at a temperature in the range from ?40 to +30° C., whose condensate is at least partly discharged.

Abstract: A method for producing a mixture of ethylene and carbon monoxide by contacting ethane and an oxygen source at a temperature of at least 500° C. to produce ethylene and carbon monoxide. A method for producing an alkyl propionate by steps of: (a) contacting ethane and an oxygen source at a temperature of at least 500° C. to produce ethylene; (b) contacting an alcohol, ethylene and carbon monoxide with an ethylene carbonylation catalyst to produce the alkyl propionate; and (c) separating the alkyl propionate from byproducts and starting materials. The method further comprises condensing the alkyl propionate with formaldehyde to produce an alkyl methacrylate.

Abstract: Disclosed is a method for the catalytic hydrogenation of methylol alkanals of general formula (I), where R1 and R2 independently represent an additional methylol group or an alkyl group having with 1 to 22 carbon atoms, or an alkyl group with 1 to 22 C atoms, or an aryl group or aralkyl group with 6 to 33 carbon atoms, in the liquid phase on a hydrogenation catalyst. The inventive method is characterized in that a pH value ranging between 6.3 and 7.

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: 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: Allyl alcohols are converted into corresponding aldehydes or ketones in a high yield under a mild condition by using an inexpensive aluminum alkoxide as an Oppenauer oxidation catalyst and a hydride acceptor. Thus, there is provided an industrially useful method for converting allyl alcohols to corresponding aldehydes or ketones.

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: A process for producing 3-hydroxypropanal includes reacting formaldehyde and acetaldehyde to form an aqueous solution of acrolein; and hydrating the aqueous solution of acrolein to form 3-hydroxypropanal, wherein the aqueous solution of acrolein is capable of being hydrated to 3-hydroxypropanal without having to remove excess formaldehyde or acetaldehyde.

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: Methylolalkanal of the formula II (R=CH2OH, C1-C22-alkyl, aryl or C6-C22-aralkyl) is prepared spe-wise by a) reacting a C2-C24-aldehyde with formaldehyde in the presence of a tertiary amine, b) separating the reaction mixture i) into a bottom fraction comprising the compound of formula II and an incompletely methylolated compound of the formula III and a distillate stream comprising unconverted or partially converted starting materials, or ii) into an aqueous phase and an organic phase, and recycling the distillate stream or the organic phase to a), and c) subjecting the bottom fraction or the aqueous phase i) to a catalytic or thermal reaction to convert the compound of formula III to the compound of formula II and to a corresponding methylene compound of formula IV (R′=H or R) and ii) separating the reaction product into an overhead stream comprising the compound of formula IV and unconverted formaldehyde which is recycled to a

Abstract: A process for the preparation of polyalcohols comprises the stages:(a) Reaction of an alkanal or ketone with formaldehyde in aqueous solution in the presence of a tertiary amine, to form a formates containing polyalcohol product mixture,(b) removal of water, excess tertiary amine, excess formaldehyde(c) heating of remaining mixture from (b) with removal of further formaldehyde and tertiary amine with formation of the formates of the polyalcohol,(d) transfer of tertiary amine removed from stage (b) and/or from stage (c), to synthesis stage (a) and/or to the subsequent transesterification stage (e),(e) transesterification of the resulting formates of the polyalcohol from stage (c) with an alcohol of the formula ROH in the presence of a transesterification catalyst to give polyalcohols and formates of the formula ##STR1## where R is a hydrocarbon radical, preferably alkyl of 1-6, particularly preferably 1-2, carbon atoms, and(f) isolation of the polyalcohols.

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: A process for the preparation of acyloins of the general formula I ##STR1## in which R.sup.a and R.sup.b are the same or different and stand for hydrogen or an optionally substituted C.sub.1 -C.sub.20 alkyl, an optionally substituted C.sub.6 -C.sub.10 aryl, an optionally substituted C.sub.7 -C.sub.12 aralkyl, an optionally substituted heteroaryl, or an optionally substituted heterocycloalkyl group, except for autocondensation products of formaldehyde, wherein an aldehyde of the formula IIR.sup.a CHO, (II)is reacted, in the presence of a catalyst, with an aldehyde of the formula IIIR.sup.b CHO, (III)in whichR.sup.a and R.sup.b have the above meanings and at least one of the radicals R.sup.a and R.sup.

Abstract: A process for condensing aldehydes where an aldehyde having an a hydrogen and having the formula R.sub.1 CHO, wherein R.sub.1 is selected from alkyl having one to twelve carbon atoms and aralkyl having one to fourteen carbon atoms, is combined with hydrated MgO to form a reaction product comprising an aldol of said aldehyde, the unsaturated aldehyde derived by dehydration of said aldol, or mixtures thereof. In a second embodiment, a first composition selected from aldehydes containing an a hydrogen and having the formula R.sub.1 CHO, wherein R.sub.1 is as defined above, is combined with a second composition selected from aldehydes having the formula R.sub.2 CHO, wherein R.sub.2 is selected from H, alkyl having one to twelve carbon atoms, and aralkyl having one to fourteen carbon atoms, and with hydrated MgO, to form a reaction product mixture comprising an aldol of said aldehyde, the unsaturated aldehyde derived by dehydration of said aldol, or mixtures thereof.

Abstract: Neopentyl glycol is made from isobutyraldehyde and formaldehyde. The formaldehyde may be in the form of paraformaldehyde or aqueous formaldehyde. The aldol reaction product is mixed with a lower alcohol prior to hydrogenation to promote hydrogenolysis and allow recovery of high purity product by simple distillation. In a less preferred mode, the alcohol may be added after hydrogenation, resulting in a smaller improvement over previous processes.

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 of aldol condensation of an active hydrogen-containing compound by a gas-phase reaction by feeding a gaseous active hydrogen-containing compound to a reactor provided with a fixed bed solid catalyst, which process is characterized in that an indirect heat transfer type, non-isothermal reactor is used to perform the aldol condensation efficiently in a commercial scale.

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: The present invention provides an aldol condensation dehydration catalyst, a process for preparing the same comprising reacting an aluminium salt with at least one magnesium compound selected from the group consisting of magnesium oxide and magnesium hydroxide to support thereon an aluminium compound and heating said supported product at a temperature in the range from 350.degree. to 700.degree. C., and a process for preparing an aldol condensation dehydrate by using the process.

Abstract: Magnesium.aluminium complex compound useful for aldol condensation dehydration is prepared by allowing a solution of magnesium salts and a solution of aluminium salts to react with ammonia and then heating the thus obtained precipitate at a temperature of 400.degree.-700.degree. C.

Abstract: Neopentyl glycol is made by reacting isobutyraldehyde with paraformaldehyde in the presence of a tertiary amine and cadmium or yttrium oxide; then hydrogenating the resulting reaction mixture containing hydroxypivaldehyde and at least about 20% 3-hydroxy-2,2-dimethylpropylhydroxypivalate.

Abstract: Disclosed is a continuous process for the manufacture of 2-ethyl-2-(hydroxymethyl)hexanal wherein 2-ethylhexanal, formaldehyde and a tertiary amine are continuously fed to a reaction zone and crude product comprising an aqueous phase and an organic phase containing 2-ethyl-2-(hydroxymethyl)hexanal and 2-ethylhexanal is continuously removed from the reaction zone. Also disclosed are processes for (1) the azeotropic distillation of the organic phase of the crude product whereby unreacted 2-ethylhexanal is recovered and (2) the catalytic hydrogenation of the refined, organic phase of the crude product to produce 2-butyl-2-ethyl-1,3-propanediol.

Abstract: Neopentyl glycol is made from isobutyraldehyde and paraformaldehyde; the aldol reaction product is directly mixed with a lower alcohol for hydrogenolysis.

Abstract: Solid solutions of magnesium oxide-aluminum oxide related to hydrotalcite and what previously has been referred to as synthetic hydrotalcites, have been prepared with a surface area in excess of 250 m.sup.2 lg, especially at low Mg/Al atom ratios. Such high surface area materials are found to be quite effective in the aldol condensation of aldehydes, 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.

Abstract: Neopentyl glycol is made by reacting isobutyraldehyde with paraformaldehyde in the presence of a tertiary amine and one or more oxides of elements of Groups IB, IVA, IVB, VA, VB, VIB and VIII of the periodic table; then hydrogenating the resulting hydroxypivaldehyde-containing product.

Abstract: Basic intermediate or large pore zeolites having a Constraint Index less than 12 are useful as catalysts in the dehydrogenation-aromatization of cyclie dienes, in the isomerization of olefins and in the aldol condensation, and particularly in the cyclization of acetonylacetone to 3-methyl-2-cyclopenten-1-one.

Abstract: Alkanals having a 2-alkyl branch are obtained from mixtures which contain the alkanals having a 2-alkyl branch in addition to n-alkanals, 3-alkylalkanals and/or further isomers by a process in whicha) the alkanal mixture is reacted with an aqueous formaldehyde solution in the presence of a secondary amine and of a carboxylic acid as a catalyst,b) the aqueous phase containing the catalyst and any unconverted excess formaldehyde is separated off andc) the alkanals having a 2-alkyl branch are isolated by distillation from the condensates of the other alkanals with formaldehyde.

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: 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 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 aqueous media and in the presence of a food grade or natural nonionic emulsifier, 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 thereof, 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 aqueous media and in the presence of a food grade or natural nonionic emulsifier, 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 thereof, 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 and ionic surfactant or emulsifier.

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: Novel ether-aldols of the general formula (I) ##STR1## where R.sup.1 and R.sup.2 are each alkyl, can be prepared by reacting a 2-alkylacrolein (H.sub.2 C.dbd.CHR.sup.2 --CHO), an alcohol (R.sup.1 OH) and formaldehyde, preferably aqueous formaldehyde, in the presence of a tertiary amine.

Abstract: A process is disclosed for the aldol condensation of enolizable aldehydes to alpha, beta-unsaturated aldehydes, at high selectivities, employing a metal carboxylate catalyst.

Abstract: Alpha, beta-unsaturated aldehydes are prepared by reacting formaldehyde and a reactant aldehyde of formula RCH.sub.2 CHO wherein R is a member of the class consisting of -H, -alkyl, -aryl, -aralkyl, -cycloalkyl, and -alkylaryl radicals in the presence of AMS-1B borosilicate crystalline molecular sieve catalyst. Metacrolein is prepared from propionaldehyde and formaldehyde.

Abstract: A process for the preparation of 2-methylene aldehydes is disclosed wherein formaldehyde is reacted with an aldehyde of the general formula R--CH.sub.2 CHO, where R stands for a substituted or unsubstituted organic radical having from 2 to 12 carbon atoms. The reaction takes place in the presence of a mixture of a secondary amine and an organic carboxylic acid having up to 5 carbon atoms.

Abstract: A process for the preparation of 2,2-dimethylolalkanals is disclosed wherein formaldehyde is reacted with an aldehyde of the formulaRCH.sub.2 CHO (I)whereinR denotes a straight-chain or branched alkyl radical with up to 12 carbon atoms where the radical can be substituted by an alkyl or alkoxy group with 1 to 3 carbon atoms in each case wherein the molar ratio of aldehyde of formula I to formaldehyde is 1:8 to 20, the reaction being carried out at a temperature in the range of 5.degree. to 100.degree. C. in the presence of 0.01 to 0.5 mol (per mol of aldehyde of formula (I)) of a catalyst consisting essentially of a hydroxide or carbonate of an alkali metal or alkaline earth metal or an unbranched tertiary aliphatic amine.

Abstract: An improvement in a process for the preparation of 2,2-dimethylolalkanal of the formula ##STR1## where R denotes an optionally substituted aliphatic radical by reacting 2-alkylacrylaldehyde with formaldehyde in presence of water and a base, the improvement residing in employing an aldehyde of the formula ##STR2## wherein R has the meaning indicated above and a mol ratio of the same to formaldehyde of 1:8-30 at a temperature in the range from -10 to 100.degree. C.

Abstract: Chemical control of aldol reactions has been achieved by employing a combination of inorganic base-cationic or neutral surfactant catalysts with organic carbonyl compounds.