Title of Invention

"AN IMPROVED PROCESS FOR THE PREPARATION OF DIHYDROXY ALKANES"

Abstract

An improved process for the preparation of dihydroxy alkenes using titanium silicate by mixing of substrate having conjugated double bonds, water solvent, oxidising agent and heterogenous catalyst TS-1 (titanium silicate) in the ratio ranging about 2.0-5.0: 5-25: 0-25: 4-25: 1-5, heating the mixture as obtained in step (a) in an autoclave at a tempeature ranging 50°-100°C for a period ranging 1 to 12 hours, followed by cooling of the reaction mixture to ambient temperature and separating of titanium silicate and solvent by known methods to obtain the mixture of dihydroxy alkenes. Dihydroxy alkenes is important industrial chemicals.

Full Text

This invention relates to an improved process for the preparation of dihydroxy alkenes using titanium silicate and particularly to a process for preparation of mixture of 1,4-and 1,2-butenediols from 1,3-butadiene. More particularly this invention relates to a Heterogeneous catalytic process for 1,4- and 1,2- dihydroxylation of 1,3- butadiene to 1,4-butenediol and 1,2-butenediol, wherein a mixture of 1,3-butadiene, water and an oxidant is contacted with a catalyst in a polar solvent. 1,4-Butenediol is an important industrial chemical. For example, it is used in the production of endosulphone, chlorinated bicycle [2.2.1]heptene-(2)-bis-(oxyalkylene 5,6) sulphite as insecticide and vitamin B6. It is hydrogenated to a versatile intermediate for the chemical intermediate 1,4-butanediol which in turn is used in the product of polyurethanes and poly(butylene terephthalate)polyurethanes and also used to prepare the useful industrial solvent tetrahydrofuran and can be converted to -butyrolactone which in turn can be converted into polyvinylpyrrolidone and N-methylpyrrolidinone. 1,2-Butanediol is used for modified polyester and polyurethanes without the use of CFC's. In the prior art, preparation of 1,4-butenediol is achieved by several methods. There are five methods known by which 1,4-butenediol (also known as 2-butene-l,4-diol) can be manufactured. The first method involves the partial hydrogenation of 2-butyne-l,4-diol using catalysts Ni-Cr (Ref: U.S.S.R. (1973) 391,123) and Pd-Cu/BaSO4 (Ref: Ger. (East) Offen. DD (1987) 249,709). The second method involves the halogenation (X=C1, Br) of 1,3-butadiene using copper bromides or chlorides to produce 1,4-dihalo-2-butene which was further hydrolysed to 1,4-butenediol (Ref. U.S.U S (1980) 4,306,100). The oxidation of butadiene with oxidant.s such as O and H2O2 using various catalyst such as 5% Pd/C-Phl rRef: Jpn K.okni Koho JP (1984) 59 84,8;; i',, CuBr and other Ni, Co, Cr, Mn catalysts (Ref: Eur.Pat. Appl. (1979) 1325), Pd/NaOAc (Ref:Japan (1974) 74 48,292) constitutes the third method. In the fourth method, transcsterificaticn of the 1,4-butenediacetate which can be prepared from 1,3-buladiene or from I /Mnilyncdio] with meihanol catalysed by basic type catalyst (Kef: Jpn Tokkyo Koho JP (1987) 62 54,778) has been reported. Hydrolysis and rearrangement of the epoxybutenc which can be obtained by monoepoxidation of 1,3-huiadicnc by various catalysts (Ref: 1) JCS, Chem. Commun. (1992) 1073; 2) Bur. Pat. Appl. EP (1980) 43,192) to 1,4-butenediol has been achieved using various acid catalysts such as SiO2/TiO2/F (Ref; Ger. Of fen DE (1995) 4.429,699), 57% UK)., (Ref: Jpn Kokai Tokkyo Koho (1979) 79,79,214) KI/H2SO4 (Ref: Jpn Kokai Tokkyo Koho JP (1982) 82,02,227), Cubr (Ref: Jpn. Kokai Tokkyo Koho (1979) 79 73,710), copper supported on SiO2 and AlO3, (Ref: US (!996) 5,530,167). The abovcmenlioncd processes in the prior art are known to be useful for the preparation of 1,4-butenedioi, however they suffer from following drawbacks. 1. For the hydrogcnation of acetylenic diol hydrogen gas (high pressure) is used. Hydrogen is a gas of low molecular weight and therefore high diffusibility, is easily ignited and presents considerable hazards, particularly on the large scale. 2. The halogenalion method involves the use of stoichiometric amount of CuBr, CuCI lo produce dihalo compounds which are then hydrolysed using basic catalysts to 1,4-butcncdiol. This method obviously involves many steps. It also applies to transestcrification method. 3. Most of the methods reported in the prior art involves homogeneous catalysts, the separation of these homogeneous catalysts from the reaction products is a major drawback. 4. Oxidation of 1,3-butadienc to 1,4-butenediol involves expensive homogeneous catalysts such as Pd, Pt, Rh etc with low conversion and selectivity. The oxidation also involves high pressure and temperature. 5. Hydrolysis and rearrnngcment of epoxybutene, though an attractive method, involves highly acidic reagents such as 57% HIO4, KI/H2SO4 and dangerous fluorine gas used in combination with SiO2/TiO2. The monoepoxidalion of 1,3- butadiene to epoxybutene is not easy, involving high technology with silver catalyst. In view of all the above disadvantages of the prior art, it is desirable to provide a process, that is, safe, inexpensive, single step and simple. It is therefore, an object of the present invention to provide a single step, simple and easier process for the dihydroxylalion of 1,3-butadienc to ;\ mixture of 1,2-,-iind 1,4-butenediols using a heterogeneous catalyst that can be easily separated from the product mixture and reused. The catalyst used in the present invention is prepared by the process described in papers published in Appl. Catal. 57 (1990)L1 and J. Catal. 130, (1991). Accordingly, the present invention provides An improved process for the preparation of dihydroxy alkenes such as herein described using titanium silicate and the said process comprising a) mixing of substrate having conjugated double bonds, water, solvent, oxidising agent and heterogenous catalyst TS-1 (titanium silicate) in the ratio ranging about 2.0-5.0: 5-40: 0-25: 4-25: 1-5 b) heating the mixture as obtained in step (a) in an autoclave at a tempeature ranging 50°-100°C for a period ranging 1 to 12 hours, followed by cooling of the reaction mixture to ambient temperature, c) separating of titanium silicate and solvent by known methods to obtain the mixture of dihydroxy alkenes. In one of the embodiments of the present invention the heterogeneous catalyst TS-1 (titanium silicalite) is used in the process of the present invention is prepared by the the process described in Appl. Catal. 57 (1990) LI and J. Catal. 130, (1991) 1. In other embodiment of the present invention the oxidising agent used may be such as hydrogen peroxide (15-50%) or f-butyl peroxide, preferably hydrogen peroxide. In yet another embodiment the solvent used may be such as but not limited to acetone, methanol, acetonitrile, water and mixture thereof. In a feature of the present invention the catalyst could be reused for the reaction several times without affecting the catalytic property. In yet another feature the completion of the reaction is established by gas chromatographic methods. The- ' process of the present invention is described herein below with reference to examples which are illustrative oriiy and should not be construed lo limit the scope of the present invention in any manner. EXAMPLE 1 A mixture of 1,3-buladicne (3 parts), water (5 parts), acelor.ilrilc (20 parts), 15% aqueous H2O2. (20 parts) and TS- 1 ( 1 part) in an autoclave was heated at 60°C for 4 hours. The catalyst was filtered off and the filtrate was evaporated to afford the mixture of 1,2- and 1 ,4-buteiiediols. [Yield: 1.1 part, selectivity 70%, molar ratio of 1,2- vs 1,4-butenediol = 2.12, (GC)]. EXAMPLE 2 A mixture of 1,3-butadienc (2.5 parts), water (20 parts), 25% aqueous H2O2.(25 parts) and TS-I ( 1 part) in am autoclave was heated at 80°C for 4 hours. The catalyst was filtered off and the filtrate was evaporated to afford the mixture of 1,2- and 1,4-butenediols. [Yield: 0.95 part, selectivity 60%, molar ratio of 1,2- vs 1,4-butenediol = 7.8.GC] EXAMPLE 3 A mixture of 1,3-butadicne (3 parts), water (25 parts), acetone (5 parts), 25% aqueous H2O2, (12 parts) and TS-1 (I part) in an autoclave was heated at 70°C lor 2 hours. The catalyst was filtered off and the lillrate was evaporated lo afford the mixture of 1 ,2 and J.4-bulcncdiols. [Yield: 1.2 part, selectivity 85.33%, molar ratio of 1,2- vs 1,4-hutcnediol = 5.27, (GC)|. EXAMPLE 4 A mixture of 1,3-butadicne (3.1 parts), water (25 parts), acetone (5 parts), 30% aqueous H2O2. (8 pails) aiul TS-I (I part) in an autoclave was heated at70°C for 2 hours. The catalyst was filtered off and the filtrate was evaporated to afford the mixture of 1,2- and 1,4-hutcncdiols. (Yield: 1.2 part, selectivity 87.3%, molar ratio of 1,2- vs 1,4-butencdiol - 5.6, (GC)] EXAMPLE 5 A mixture of 1,3-buladicne (2 parts), water (25 parts), acetone (10 parts), 30% aqueous H2O2.(4 parts) and 1% v/v sulphuric acid (5 parts) in an autoclave was heated at 70°C for 4 hours. The catalyst was filtered off and the filtrate was evaporated to afford the mixture of 1,2-and 1,4-buIenediols. | Yield: 1.15 part, selectivity 95.6%, molar ratio of 1,2- vs 1.4-butenediol = 7.03. (GC)]. EXAMPLE 6 A mixture of isoprene (5 parts), water (5 parts), acetone (25 parts), 25% aq. H2O2.- (25 parts) and TS-1 (1 part) in an autoclave was heated at 70°C for three hours. The catalyrt was filtered off and filtrate was evaporated to afford the mixture of 1,2- dihydroxy 2-methyl 3-butenc and 1,4 dihyclioxy 2-methyl 2-butene. [Yield: 3.7 part, selectivity .-.0%, molar ratio of 1,2- vs 1,4-dic.Is ± 2.3, (GC)]. EXAMPLE 7 A mixture of isopreim (5 parts:. w«ler (5 parts), acetonitrile (20 parts) 25% aq. H2O2 (25 parts) and TS-1 (1 part) in an autoclave was heated at 70°C for three hours. The catalyst was filtered off and filtrate was evaporated to afford the mixture of 1,2- dihydroxy 2-melhyl 3-hutcne and 1,4-dihydroxy 2-mcthyl 2-bulene. [Yield: 3.2 part, selectivity 65%, molar ratio of 1,2- vs l,4-diols= 1.8, (GC)|. EXAMPLE 8 A mixture of isoprene (5 parts), water (5 parts), acetone (25 parts) 25% aq.H2O2 (10 parts) and TS-1 (I part) in an autoclave v/as heated at 70°C for three hours. The catalyst was filtered off and filtrate was evaporated to afford the mixture of 1,2- dihydroxy 2-methyl 3-butene and 1,4 dihydroxy 2 methyl 2-bulene. [Yield: 2.2 part, selectivity 60%. molar ratio of 1,2- vs 1,4-diols = 2.4, (GC)|. EXAMPLE 9 A mixture of ocimene (3,7- dimethyl-1,3,6-octatriene (5 purls), water (5 parts), acetone (25 parts) 25% aq.H2O2. (25 parts) and TS-1 (1 part) in an autoclave was healed at 70°C for three hours. The catalyst was filtered off and filtrale was evaporaled to afford the mixture of 1,2-dihydroxy 3,7-dimclhyl-3,6-octadtene and 1,4-dihydroxy 3,7-dimethyl-2.6-(>clailienc| Yield: 2.0 part, selectivity 70%, molar ralio of 1,2- vs 1,4 diols = 2.8, ADVANTAGES: 1. The main advantages of the present invention to provide a non-hazardous, an environmentally free, single step, simple and easier process for the dihydroxylalion of conjugated dicncs to a mixture of dihydroxy alkenes using a heterogeneous catalyst. 2. The catalyst can be separated from the product mixture and could be used for the reaction several times without affecting the catalytic properly, 3. The completion of the reaction is established by gas chromalographic methods. We Claim: 1. An improved process for the preparation of dihydroxy alkenes using titanium silicate and the said process comprising a) mixing of substrate of the kind such as herein described having conjugated double bonds, water, solvent and oxidizing agent of the kind such as herein described and heterogeneous catalyst TS-1 (titanium silicate) in the ratio ranging about 2.0-5.0: 5-40: 0-25: 4-25: 1-5 b) heating the mixture as obtained in step (a) in an autoclave at a temperature ranging 50°C-100°C for a period ranging 1 to 12 hours, followed by cooling of the reaction mixture to ambient temperature, c) separating of titanium silicate and solvent by known methods to obtain the mixture of dihydroxy alkenes. 2. An improved process as claimed in claim 1 wherein the substrate used is selected from the group of compounds having double bond consisting of 1,3-butadiene, isoprene, and ocimene (3,7- dimethyl -1,3,6-octatriene). 3. An improved process as claimed in claim 1 wherein the oxidizing agent used is selected from a group comprising hydrogen peroxide or t-butyl peroxide. 4. An improved process as claimed in claims 1 wherein, the solvent used is selected from acetone, methanol, acetonitrile, water and mixture thereof. 5. An improved process for the preparation of dihydroxy alkenes as fully described herein before with reference to examples contained therein.

Documents:

3068-del-1998-abstract.pdf

3068-del-1998-claims.pdf

3068-del-1998-correspondence-others.pdf

3068-del-1998-correspondence-po.pdf

3068-del-1998-description (complete).pdf

3068-del-1998-form-1.pdf

3068-del-1998-form-19.pdf

3068-del-1998-form-2.pdf