Title of Invention

"AN IMPROVED PROCESS FOR CATALYTIC HYDROFORMATION OF WATER SOLUBLE ALKENES"

Abstract

An improved process for the catalytic hydroformylation of water soluble alkenes This invention relates to an improved process for catalytic hydro-formylation of water soluble alkenes. More particularly it relates to the hydroformylation of these alkenes in the two phase medium with enhanced rate of the reaction and easy separation of catalysts and products by phase separation. The reaction comprises of two phases viz organic phase and aqueous phase. Aqueous phase consist of an olefin and P-containing water soluble ligand (promoter). The organic phase consists of a metal complex catalyst comprising of group VIII element such as Rh, Ru Ir or Co with water immiscible solvent. The aldehydes products formed by hydroformylation have a variety of applications in industries as solvents, plasticizers, detergent chemicals, fragrance chemicals, intermediates, pharmaceuticals etc. The improvement proposed here relates to rate enhancement due to a promoter in non-catalyst phase.

Full Text

This invention relates to an improved process for hydro- formylation of water soluble alkenes. More particularly it relates to the hydroformylation of these alkcnes in the two phase medium. Still more particularly it ralates to a process of hydroformylation with enhanced rate of the reaction and easy separation of catalysis and products by phase separation. The reaction comprises of two phases viz organic phase and aqueous phase. The aqueous phase consists of an olefin and P- containing water soluble ligand (promoter). The organic phase consists of a metal complex catalyst comprising of group VIII element such as Rh, Ru, Ir or Co with water immiscible solvent. The aldehydes products formed by hydroformylation have a variety of applications in industries as solvents, plasticizcrs, detergent chemicals, fragrance chemicals, intermediates, pharmaceuticals etc. The improvement proposed here relates to rate enhacement due to a promoter in non-catalyst phase. In the prior art the hydroformylation or oxo reaction is a catalytic reaction and involves addition of carbon monoxide and hydrogen to an olefin to produce aldehydes. Cobalt and Rhodium catalysts have so far been utilized for commercial application of this technology and these are essentially single phase homogeneous catalytic processes (Cornils B. (1980)). Particularly The Union Carbide LP Oxo Process (US Pat No. 386046 (1970)) using HRh(CO)(PPh3)3 catalyst was a significant development in recent years. This has been commercially used for hydroformylation of propylene to butyraldehyde, however, this process is not applied for hydroformylation of higher olefins and substituted alkenes, since the product arc not volatile, leading to problems in catalyst product separation. In cases where the substrate and product have relatively higher solubility in water compared to organic phase, use of an extractive method has been suggested to Qvercome problems associated with catalyst/product separation (Shimizu Ger. Offen. 2538364 (1976), Shimizu and Tamura Ger. Offen 7868709 (1978)). In similar cases where the substrate and product have more solubility in water relative to organic phase, the use of water soluble catalyst (of the type developed Rhurchemie and Rhone Poulenc ) is not applicable due to problems associated with catalyst/product separation. In this invention we propose the use of a ligand in the aqueous phase coupled with organic phase catalyst system to promote an intcrfacial reaction. The use of this process gives enhancement in the reaction rate as compared to conventional biphasic catalyst system (Chaudhari ct al Indian Patent filed No 701/Dcl/94 dated 16/12/94 and 758/Del/94 dated 30/12/94). However, it is not a prerequisite in this process that the substrate should have reasonable solubility in the organic phase as compared to the hitherto known processes. It is also in these respect that this process offers unique advantages over the conventional catalyst systems. This process can be used even for hydroformylation of substrates which have very poor solubility in the organic phase. The processes described in the prior art for the hydroformylation of water soluble olefins are likely to suffer from the problems associated with solvent reactivity, product separation and catalyst recycle/recovery, besides solubility limitations. The object of the present invention, therefore is to enhance the reaction rate of hydroformylation reaction of water soluble alkene by providing an improved process for hydroformylation. Accordingly the present invention provides an improved process for catalytic hydroformylation of water soluble alkenes containing carbon atoms in the range of 2-22 and is selected from allyl alcohol,2-butene-1,4-diol,maleic acid, fumaric acid or the like which comprises: preparing an aqueous solution of water soluble alkene having concentration in the range of 10-30 % w/v, adding a water soluble phosphorous containing ligand (promoter) as herein described to this solution .preparing another solution of a metal complex catalyst comprising of Group VIII elements as herein described in water immiscible solvent as herein described, mixing the solutions in a reactor at a temperature ranging between 60 to 180 deg.C .pressuring the reactor with the mixture of CO and H2 at 300 to 600 psi, stirring the mixture at a speed of 300 to 2000 rpm and constantly monitoring the rate of reaction by pressure depletion for 15 to 60 minutes,discharging the reactor, separating the catalyst in the organic phase and the product in the aqueous phase In one of the embodiments of the present invention the exemplary water soluble alkenes contain carbon atomes in the range of 2-22 and is selected from allyl alcohol, 2-butene-1,4-diol, maleie acid, fumaric acid or the like. In another embodiment the exemplary solvents immiscible in water is selected from aliphatic and aromatic hydrocarbon solvents like hexane, heptane, octane, decane, benzene, touluene, ortho, meta, or para xylene, cyclohexane, ethyl acetate, diethyl ether, or higher alcohols. In yet another embodiment the metal complex catalyst consists of complexes having group VINA metals (e.g. cobalt, rhodium, ruthenium and iridium) or complexes of the said elements which are prepared by the methods mentioned in the prior art references. In yet another embodiment the water soluble phosphorus containing ligands which can be employed in this invention are selected from PPhn (C6H4SO3M)3..n (M = alkali metal, alkaline earth metal/2, quaternary ammonium group): n=0, 1 or 2, Water soluble phosphines containing quaternary ammonium group eg. Amphos and phosphines c taining phospghonium or acetate, hydroxyl groups can also be used in the present invention. In another embodiment of the present invention the amount of promoter used may be 0.1 to 1.0% w/s of alkene. In Yet another embodiment of the present invention the reaction is carried out a t a temperature in the range of 30-180°C, preferably in the range of 80-120°C. The process of the invention is described in detail in the examples given bellow which are illustrative only should not be construed to limit the scope of the invention. EXAMPLE 1 The following charge consisting of aqueous and organic phases were introduced in a 50 cc Hastalloy-C, microclavc equipped with magnetic drive type agitation system and connected to a reserve of gas containing hydrogen under pressure containing equimolar mixture of Carbon Monoxide and Hydrogen. 0.046 g (5 x 10-5 mol) of HRh(CO)(PPh,)3 dissolved in a 10 cm3 toluene. The aqueous phase consisted of 170 mg of the trisodium salt of tris(sulfophenyl) phosphine (TPPTS) (0.0003 mol), allyl alcohol (2, cm3; 0.03 mol) and diluted to 10 cm3 with deaerated water. The reaction mixture was heated upto 100°C and the reaction was carried out at 400 psig of (CO + H,) and a stirring speed of 1000 rpm. The reaction was continued till the expected absorption was achieved calculated on the basis of absorption of the CO/H2. The reaction was complete in 30 minutes. The contents of the reactor showed formation of two products viz 2 methyl 3 hydroxy-propionaldchydc and 4 hydroxybutyraldehyde. No leaching of catalyst was observed in the organic phase. The Turn Over Frequency, ( herein after referred to as (TOF) (calculated as moles of allyl alcohol reacted per kg of Rh per seconds) of 0.002X, kmol/kg(Rh)/s was observed. Similarly the reaction was carried out without addition of TPPTS in the aqueous phase. The TOF observed in this case is 5x10-4 (H, kmol/kg(Rh)/s which is 6 times lower than that of with catalyst binding ligand (i.e. TPPTS). EXAMPLE 2 The following charge consisting of aqueous and organic phases was introduced in a 50 cc Hastalloy-C, microclave equipped with magnetic drive type agitation system and connected to a reserve of gas containing hydrogen under pressure containing equimolar mixture of Carbon Monoxide and Hydrogen. 0.046 g (5 x 10-s mol) of HRh(CO)(PPh3), dissolved in a 10 cm3 toluene. The aqueous phase consists of 85 mg of the trisodium salt of tris(sulfophenyl) phosphine (TPPTS) (0.0003 mol), allyl alcohol (2, cm3; 0.03 mol) and diluted to 10 cm3 with deaerated water. The reaction and contents was heated upto 100°C and the reaction was carried out at 400 psig of (CO + H2) and a stirring speed of 1000 rpm. The reaction was continued till the expected absorption was achieved. The reaction was complete in 90 min. The contents of reactior showed formation of two products viz 2 methyl 3 hydroxypropionaldehyde and 4 hydroxybutyraldchyde. The TOF value observed in this case is 0.0015 kmol/kg(Rh)/s which is 3 times more than reaction without any additive in aqueous phase. EXAMPLE 3 The following charge consisting of aqueous and organic phases was introduced in a 50 cc Hastalloy-C, microclave equipped with magnetic drive type agitation system and connected to a reserve of gas containing hydrogen under pressure containing equimolar mixture of Carbon Monoxide and Hydrogen. 0.046 g (5 x 10 5 mol) of HRh(CO)(PPh3)3 dissolved in a 10 cm1 toluene. The aqueous phase consisted of 85 mg of the Irisodium salt of tris(sulfophenyl) phosphine (TPPTS) (0.0003 mol), 1,4 butcnediol 2,cc (0.0225 mol) and diluted to 10 cm3 with dcaeratcd water. The reaction mixture was heated upto 60"C and the reaction was carried out at 400 psig of (CO + H2) and a stirring speed of 1000 rpm. The reaction was continued till the expected absorption was achieved. The reaction was complete in 150 min. The TOF observed in this case was 4.72 x 104, kmoI/kg(Rh)/s, whereas similar reaction taken without addition of TPPTS shows TOF of 1.41 x 104, kmol/kg(Rh)/s, which is 3.35 times less. Present invention gives following advantages over hitherto known processes* Hydroformylation of water soluble alkenes is achieved with improved reaction rate. * Catalyst loss by leaching to aqueous phase is negligible. We Claim: 1. An improved process for catalytic hydroformylation of water soluble alkenes containing carbon atoms in the range of 2-22 and is selected from allyl alcohol,2-butene-1,4-diol,maleic acid, fumaric acid or the like which comprises: preparing an aqueous solution of water soluble alkene having concentration in the range of 10-30 % w/v, adding a water soluble phosphorous containing ligand (promoter) as herein described to this solution .preparing another solution of a metal complex catalyst comprising of Group VIII elements as herein described in water immiscible solvent as herein described, mixing the solutions in a reactor at a temperature ranging between 60 to 180 deg.C ,pressuring the reactor with the mixture of CO and H2 at 300 to 600 psi, stirring the mixture at a speed of 300 to 2000 rpm and constantly monitoring the rate of reaction by pressure depletion for 15 to 60 minutes,discharging the reactor.separating the catalyst in the organic phase and the product in the aqueous phase by phase separation to obtain the products in the aqueous phase. 2. An improved process as claimed in claiml wherein the water immiscible solvent for the preparation of the solution is selected from aliphatic and aromatic hydrocarbon solvents like hexane, heptane, octane, decane, benzene, toluene, ortho, meta, or para xylene, cyclohxane, ethyl acetate, diethyl ether, or higher alcohols. 3. An improved process claimed in claims 1&2 wherein, the metal complex catalyst used consists of complexes having group VINA metals (e.g. cobalt, rhodium, ruthenium and iridium) or complexes of the said elements. 4. An improved process as claimed in claims 1 to 3 wherein the water soluble phosphrous containing ligands (promoter) are selected from PPhn ( C6H4SO3M)3-n (M=lakali metal, alkaline earth metal, quaternary ammonium group; n=0, 1 or 2, water soluble phophines containing quaternary ammonium group eg. Amphos and phosphines containing phosphonium or acetate, hydroxyl groups. 5. An improved process as claimed in claims 1-4 wherein the amount of promoter used ranges from 0.1 to 1.0% w/w of alkene. 6. An improved process as claimed in claims 1 to 5 wherein the reaction is carried out preferably at a temperature in the range of 80-120°C. 7. An improved process as claimed in claims 1 to 6 wherein the ratio of carbon monoxide to hydrogen used varies between 1:0.2 to 5,preferably between 1:0.8 to 1.5. 8. An improved process for the catalytic hydroformylation of water soluble alkenes as here described with reference to the examples.

Documents:

800-del-1997-abstract.pdf

800-del-1997-claims.pdf

800-del-1997-complete specification (granted).pdf

800-del-1997-correspondence-others.pdf

800-del-1997-correspondence-po.pdf

800-del-1997-description (complete).pdf

800-del-1997-form-1.pdf

800-del-1997-form-19.pdf

800-del-1997-form-2.pdf