Title of Invention

A PROCESS FOR THE PREPRATION OF 2-HYDROXY CARBOXLIC ACIDS

Abstract Two step preparation of hydroxy carboxylic acid (e.g. lactic acid) is achieved; Step 1) Carbonylating an enol ester (e.g. vinyl acetate) in presence of a hydroxyl compound (e.g. Methanol) using a palladium catalyst (e.g. PdC12(PPh3)2), a O-, N- and/or P-containing ligand and a solvent, at 50-150°C/50-2000 psig to yield hydroxy ester (e.g. methyl lactate) and acetoxy ester (e.g. methyl-2-acetoxy propionate), separating and recycling the catalyst for carbonylation; Step 2) hydrolyzing the step 1 products to 2-hydroxy carboxylic acids (e.g. lactic acid) using acid catalysts (e.g. TsOH, aq HC1, resin) at 10-125°C, separating and recycling the catalyst for hydrolysis.
Full Text A PROCESS FOR THE PREPARATION OF 2-HYDROXY CARBOXYLIC ACIDS
Field of the present invention
The present invention relates to a process for the preparation of 2-hydroxy carboxylic acids. Particularly the present invention relates to a process wherein an enol ester and a hydroxyl compound react with carbon monoxide in presence of a palladium catalyst, containing one or more ligands having one or more coordinating N, O and/ or P atoms and a solvent at a temperature and a pressure, to produce 2-acetoxy ester and/ or 2-hydroxy ester of corresponding carboxylic acid, of the corresponding carboxylic acid which on further catalytic hydrolysis produce 2-hydroxy carboxylic acid. The process has potential importance when applied to vinyl acetate. In a preferred embodiment vinyl acetate reacts with a hydroxyl compound and carbon monoxide to give 2-acetoxy propionic acid or 2-acetoxy propionate ester and/ or lactate ester, which can be converted to lactic acid on hydrolysis. Lactic acid is important commercially in baking industry, cheese industry, in dying wool, to make plasticisers for resin, etc.
Background and prior art references of the present Application Lactic acid has been produced industrially by fermentation of molasses, but the process is costly and inefficient, and produces large amount of byproducts, making product separation and purification expensive. Another commercial rout for lactic acid is hydrocyanation of acetaldehyde followed by hydrolysis of cyanohydrin with H2SO4. This rout is highly corrosive, consumes stoichometric amount of toxic HCN and H2SO4. Further the process uses expensive HCN and produces stoichometric amount of (NH4)SO4
Alkoxycarbonylation of certain aceloxyolefinic compounds is reported in US patents 4,257,973 and 3,857,319. German patent 1,221,224 and Swiss patent 589,571 disclose carbonylation of alcohols or phenols with CO and olefins. However neither patent discloses the alkoxycarbonylation of enol acylates with CO and hydroxyl compound. US patent 4,072,709 provides a process for the production of lactic acid in which, alpha-aceloxy-propanaldehyde formed by hydroformylation of vinyl acetate is oxidized to alpha-aceloxy-propionic acid, which is further hydrolysed to lactic acid. However, the process involves three steps for the formation of lactic acid. US patent 4,377,708 provides a process for hydrocarbonylation of vinyl acetate using CO and water as reactants with vinyl acetate. In the process, special precautions are taken for

the stability of the catalyst, reactants and products. The process needs to maintain the
concentration of water not more than 3 weight percent of the medium, so as to avoid
hydrolysis of reactant vinyl acetate to acetic acid and acetaldehyde. European patent
0144188 provides a process for alkoxycarbonylation of enol esters with hydroxyl
compounds using Pd, Rh and Ni catalysts and further hydrolysis of the products to
hydroxy acids. However, the process operates at low concentration of hydroxyl
compound ( separation method and reuse, showing inefficiency of the catalyst. Palladium
catalysed hydrocarbonylation of enol esters have been reported in Bull Chem. Soc.
Jpn. 69, 1337-1345 (1996). However, the process needs high pressure of CO (150-250
atm.) and a base such as pyridine or its derivatives. Furthermore, loading of the
catalyst is high (5 mol% of enol ester) which gives less activity in terms of turn over
number. Also the process is applicable only for acetoxy esters and hydroxy esters, and
not for the important product like hydroxy acids such as lactic acid.
As can be seen, the pri9r art processes suffer from several disadvantages such as use
of costly and toxic chemicals, formation of large amount of byproducts, low catalyst
activity, and catalyst and reactant stability. It is therefore necessary to develop a
process for preparation of 2-hydroxy carboxylic acids, which overcomes the
drawbacks enumerated above.
Objects of the present invention
The main object of the present invention is to provide a process for the preparation of
2-hydroxy carboxylic acids, which overcomes the drawbacks of low activity, catalyst
stability, use of toxic chemicals, and the severe operating conditions.
Another object of the invention is to provide an efficient catalytic process for the
preparation of 2-hydroxy carboxylic acids via carbonylation of enol ester and
subsequent hydrolysis of ester of the corresponding 2-acetoxy carboxylic acid and/ or
ester of the corresponding 2-hydroxy carboxylic acid that operates at milder reaction
conditions.
Still another object of the present invention is to provide the methods for catalyst
separation and their reuse.
Summary of the present invention
These and other objects of the present invention are achieved by providing a process
comprising palladium in presence of one or more ligands containing coordinating
nitrogen and/ or oxygen and/ or phosphorus atom/s catalysed carbonylation of enol
Ester in presence of a hydroxyl compound to yield 2-acetoxy ester and/or 2-hydroxy
ester of the coreesponding carboxylic acid at milder reaction conditions, which on
further hydrolysis using acid catalysts to give 2-dydroxy carboxylic acid. In the process
of the invention both carbonylation and hydrolysis catalysts are reusable.
Detailed description of the present invention
Accordingly the present invention provides an efficient process for the preparation of 2-
hydroxy carboxylic acids using reusable catalyst, said process comprises the steps of,
a. carbonylation of an enol ester with carbon monoxide and a hydroxyl compound in
presence of a palladium catalyst wherein the catalyst is selected from palladium (II) or
palladium (0) compound having formula ABxCy, where
A=palladium,
B=organic ligand containing one or more coordinating nitrogen and/or oxygen and/or
phosphorus atom/s and,
C= any halogen atom such as F, CI, Br or I and (x+y) is an integer ranging from 1 to 4,
individually x and y can vary in the range of 0 to 4 wherein the molar ratio of catalyst
and enol ester is in the range of 20:1,000 to 30:1500 and a solvent at a temperature
in the range of 50-250°C, at a pressure in the range of 50-250°C, at a pressure in the
range of 50-2000 psig, to obtain carbonylated ester,
b. hydrolyzing the carbonylated ester with an acid catalyst such as herein described
at a temperature of 10-125°C, to obtain 2-hydroxy carboxylic acid.
In another embodiment in the preparation of 2-dydroxy carboxylic acids the molar concentration ratio of enol ester/catalyst used is in the range of 25 to 1,000. In yet other embodiment in the present invention the molar concentration ratio of hydroxyl compound/enol ester is not less than one.

In another embodiment the preparation of 2-hydroxy carboxylic acids the carbonylation
catalyst is recycled and used for the carbonylation step
In one of the embodiment of the present invention the enol ester is an organic
compound having formula R1C=C(R2)-0-Acyl, where R1 is H or an alkyl group
containing 1-5 carbon atoms and R2 is H or an alkyl group containing 1-5 carbon
atoms.
In another embodiment, hydroxyl compound used is a compound having formula R-
OH, where R is H or primary, secondary or tertiary alkyl group containing 1-7 carbon
atoms selected from the group of compounds such as water, methanol, ethanol,
propanol, iso-propanol, butanol, isobutanol, t-butanol, pentanol.
In yet another embodiment of the present invention the catalyst used comprises
palladium (II) or palladium (0) compound having formula ABxCy, where A stands for
palladium, B is an organic ligand containing one or more coordinating nitrogen and/or
oxygen and/or phosphorus atom/s and C is any halogen stom such as F, CI, Br or I
and (x+y) is an integer ranging from 1 to 4, individually x and y can vary in the range



of 0 to 4. Such palladium compounds can be selected from the group consisting of palladium chloride, palladium bromide, palladium iodide, and palladium acetate; or a metal complex of palladium such as bis(acetylacetonato)palladium(II), bis(triphenylphosphine)dichloropalladium(II),
bis(triphenylphosphine)dibromopalladium (II),
bis(triphenylphosphine)diiodopalladium (II), bis(pyridine)dichloropalladium(II),
bis(pyridine)didromopalladium(II), bis(pyridine)diiodopalladium(II),
bis(acetonotrile)dichloropalladium(II), bis(benzonitrile)dichloropalladium(II), and tetrabis(triphenylphosphine)palladium(0).
In another embodiment the ligand is a compound containing one or more coordinating
O atom/s selected from the group such as acetyl acetonate, salicylaldehyde, p-
toluenesulphonic acid, compounds containing one or more coordinating N atom/s
such as pyridine, pipyridine, triethyl amine, tributyl amine, quinoline, isoquinoline, o-
phenylenediamine, p-phenylenediamine, ethylenediamine, or coordinating N and O
atoms such as 8-hydroxy quinoline, bis(saliylidene)ethylenediamine, salicylaldoxime,
picolinic acid, nicotinic acid, anthranilic acid, one or more P containing compound
such as trimethyl phosphine, triethyl phosphine, tri-n-butyl phosphine, tri-t-butyl
phosphine, tricyclohexyl phosphine, triphenyl phosphine,
bis(dicyclohexylphosphinoethane), bis(dicyclohexylphosphinobutane),
bis(diphenylphosphinoethane), bis(diphenylphosphinopropane),
bis(diphenylphosphinobutane), bis(diphenylphosphinohexane). In yet another embodiment of the invention the solvent used is an organic solvent selected from toluene, benzene, chloroform, dichloromethane, dichloroethane, chlorobenzene, o-dichlorobenzene, p-dichlorobenzene or ketone selected from a group consisting of acetone, ethyl methyl ketone, diethyl ketone, acetophenone or a cyclic ether such as tetrahydrofuran, dioxan, or nitrile selected from acetonitrile, benzonitrile.
In another embodiment the carbonylation product is separated by vacuum distillation or solvent extraction using appropriate solvent, and the carbonylation catalyst is recycled and reused for the carbonylation step.
In one of the embodiment, hydrolysis of carbonylation products is carried out with the catalyst selected from the group consisting acidic catalysts as p-toluene sulphonic acid, aq. Hydrochloric acid, or a resin like amberlite at a temperature in the range of
10-125°C; the catalyst can be separated by distillation or filtration and reused for
hydrolysis.
The invention will now be described with reference to the following examples, which
are illustrated and should not be construed as limiting the scope of the invention in
any manner.
EXAMPLE 1
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
PdCl2(PPh3)2: 0.00005 mol
Acetyl acetone: 0.001 mol
Toluene: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 4 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 83.5 % conversion of vinyl acetate with 47.92 % selectivity to methyl-2-acetoxy propionate and 8.0 % selectivity to methyl lactate with turn over number of 210. (TON=Moles of the products hydrolysable to lactic acid per mole of the catalyst charged) The product methyl-2-acetoxy propionate was characterized by 'H-NMR spectroscopy after separation by evaporating the low boilers and solvent and filtering out the precipitated catalyst.
EXAMPLE 2
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
PdCl2(PPh3)2: 0.00005 mol
Picolinic acid: 0.001 mol
Toluene: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was
pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 10 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 97.66% conversion of vinyl acetate with 61.42% selectivity to methyl-2-acetoxy propionate and 18.98% selectivity to methyl lactate with turn over number of 399.4.
EXAMPLE 3
Catalyst for recycle run was obtained by filtration after evaporating the low boilers and solvent from the reaction mixture of example 2
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
Catalyst: recycled from example 2
Picolinic acid: 0.001 mol
Toluene: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 10 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 63.53% conversion of vinyl acetate with 38.08% selectivity to methyl-2-acetoxy propionate and 15.67% selectivity to methyl lactate.
EXAMPLE 4
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
PdCl2(PPh3)2: 0.00005 mmol
Nicotinic acid: 0.001 mol
Toluene: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The
contents were stirred for 4 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 60.15% conversion of vinyl acetate with 57.57% selectivity to methyl-2-acetoxy propionate and 16% selectivity to methyl lactate with turn over number of 227
EXAMPLE 5
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
PdCl2(PPh3)2: 0.00005 mol
Anthranilic acid: 0.001 mol
Toluene: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 10 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 98.9% conversion of vinyl acetate with 50.30% selectivity to methyl-2-acetoxy propionate and 20% selectivity to methyl lactate with turn over number of 356.
EXAMPLE 6
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
PdCl2(PPh3)2: 0.00005 mol
Pyridine: 0.001 mol
p-toluenesulphonic acid:0.0002 mol
Toluene: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 4 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas
chromatography. The results of the gas chromatography showed 99% conversion of vinyl acetate with 76.45% selectivity to methyl-2-acetoxy propionate with turn over number of 411.
EXAMPLE 7
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
PdCl2(PPh3)2: 0.00005 mol
Triphenylphosphine: 0.001 mol
Toluene: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 8 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 99% conversion of vinyl acetate with 2% selectivity to methyl-2-acetoxy propionate with turn over number of 10.
EXAMPLE 8
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
PdCl2(PPh3)2: 0.00005 mol
p-toluenesulphonic acid:0.0002 mol
Acetyl acetone: 0.001 mol
Tetrahydrofuran: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 4 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 91.43% conversion
of vinyl acetate with 35.67% selectivity to methyl-2-acetoxy propionate and 25.65% selectivity to methyl lactate with turn over number of 295.
EXAMPLE 9
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 0.060 mol
PdCl2(PPh3)2: 0.00005 mol
Acetyl acetone: 0.001 mol
p-toluenesulphonic acid:0.0002 mol
Acetonitrile: 20 ml
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 4 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 82.65% conversion of vinyl acetate with 4% selectivity to methyl-2-acetoxy propionate and 42.56% selectivity to methyl lactate with turn over number of 202.
EXAMPLE 10
A 50 ml autoclave was charged with the following:
Vinyl acetate: 0.025 mol
Methanol: 23 ml
PdCl2(PPh3)2: 0.00005 mol
Acetyl acetone: 0.001 mol
The contents of the autoclave were flushed thrice with carbon monoxide at room temperature. Thereafter, the contents were heated at 100°C. The autoclave was pressurized with carbon monoxide to 800 psig after the temperature was attained. The contents were stirred for 3 hours continuously. The reactor was then cooled to room temperature and the gas was vented off. The liquid contents were analysed by gas chromatography. The results of the gas chromatography showed 91.26% % conversion of vinyl acetate with 3% selectivity to methyl-2-acetoxy propionate with turn over number of 10.97.
EXAMPLE 11
Methyl lactate was separated by extracting with 15 ml water from the reaction mixture of example 3, to which 1 ml of cone. HC1 was added. Thereafter, the reaction mixture was refluxed for 3 hours. The contents were analysed by gas chromatography after cooling the reaction mixture. The results showed 58 % conversion of methyl lactate.
EXAMPLE 12
0.191 g of p-toluene sulphonic acid and 15 ml water was added to 1.46 g of methyl-2-acetoxy propionate. Thereafter, the reaction mixture was refluxed for 3 hours and the contents were analysed by gas chromatography after cooling the reaction mixture. The analysis showed 100% conversion of methyl-2-acetoxy propionate with 100% selectivity to lactic acid.
EXAMPLE 13
15 ml of water and O.lg of amberlite IR 20 resin were added to the reaction mixture of example 4. Thereafter, the contents were heated to 80°C. for 3 hours. The contents were analysed by gas chromatography. The analysis showed 17.33% conversion of methyl-2-acetoxy propionate.
EXAMPLE 14
The catalyst from example 13 was separated by filtration and added to 1.44 g of methyl-2-acetoxy propionate and 15 ml water. Thereafter the contents were heated to 80°C for 3 hours. The analysis was done by gas chromatography. The results showed 41.77% conversion of methyl-2-acetoxy propionate with 100 % selectivity to lactic acid.
ADVANTAGES OF THE INVENTION
1. The process of the invention provides an alternative catalytic system for the
production of lactic acid, which is economic and efficient.
2. The process provides the method for catalyst separation and its reuse.
3. The process operates at milder reaction conditions.

We claim:
1. An efficient process for the preparation of 2-hydroxy carboxylic acids using reusable catalyst, said process comprises the steps of,
a. carbonylation of an enol ester with carbon monoxide and a hydroxyl compound in
presence of a palladium catalyst wherein the catalyst is selected from palladium (II) or
palladium (0) compound having formula ABxCy, where
A=palladium,
B=organic ligand containing one or more coordinating nitrogen and/or oxygen and/or
phosphorus atom/s and,
C= any halogen atom such as F, CI, Br or I and (x+y) is an integer ranging from 1 to 4,
individually x and y can vary in the range of 0 to 4 wherein the molar ratio of catalyst
and enol ester is in the range of 20:1,000 to 30:1500 and a solvent at a temperature
in the range of 50-250°C, at a pressure in the range of 50-250°C, at a pressure in the
range of 50-2000 psig, to obtain carbonylated ester,
b. hydrolyzing the carbonylated ester with an acid catalyst such as herein described
at a temperature of 10-125°C, to obtain 2-hydroxy carboxylic acid.
2. A process as claimed in claim 1, wherein the molar concentration ratio of hydroxyl compound/enol ester is not less than one.
3. A process as claimed in claim 1, wherein enol ester is an organic compound having formula R1C=C(R2)-0-Acyl, where R1 is H or an alkyl group containing 1-5 carbon atoms and R2 is H or an alkyl group containing 1-5 carbon atoms.
4. A process as claimed in claim 1, wherein hydroxyl compound used is a compound having formula R-OH, where R is H or a primary, secondary of tertiary alkyl group containing 1-7 carbon atoms selected from the group of compounds such as water,

methanol, ethanol, propanol, iso-propanol, butanol, iso-butanol, t-butanol and pentanol.
5. A process as claimed in claim 1 palladium catalyst can be selected from the group consisting of palladium chloride, palladium bromide, palladium iodide, and palladium acetate; or a metal complex of palladium such as bis(acetylacetonato) palladium (II), bis(triphenylphosphine)dichloropalladium (II),
bis(driphenylphosphine)dibromopalladium (II),
bis triphenylphosphine)diiodopalladium (II),
bis pyridine)dichloropalladium (II, bis(pyridine)didromopalladium(ll),
bis (pyridine)diiodopaliadium (II), bis(acetonotrile) dichloropalladium (II),
bis(benzonitrile) dichloropalladium (II), and
tetrakis(triphenylphosphine) palladium (0).
6. A process as claimed in claim 1, wherein the ligand is a compound containing one or more coordinating O atom(s) selected from the group consisting of acetyl acetonate, salicylaldehyde, p-toluenesulphonic acid; compounds containing one or more coordinating N atom/s such as pyridine, pipyridine, triethyl amine, tributyl amine, quinoline isoquinoline, o-phenylenediamine, p-pyenylenediamine, ethylenediamine, or coordinating N and O atoms such as 8-hydroxy quinoline, bis(sliylidene) ethylenediamine, salicylaldoxime, picolinic acid, nicotinic acid, anthranilic acid, one or more P containing compound such as trimethyl phosphine, triethyl phosphine, tri-n-butyl phosphime, tri-tbutyl phosphine, tricyclohexyl phosphine, triphenyl phosphime, bis(dicyclohexylphosphinoethane), bis(dicyclohexylphosphinobutane), bis

(diphenylphosphinoethane), bis(diphenylphosphinopropane), bis(diphenylphosphinobutane), and bis (diphenylphosphinohexane).
7. A process as claimed in claim 1, wherein the solvent used is an organic solvent selected from the group of solvents containing toluene, benzene, chloroform, dichloromethane, dichloroethane, chlorobenzene, o-dichlorobenzene, p-dichlorobenzene or ketone selected from a group consisting of acetone, ethyl methyl ketone, acetophenone or a cyclic ether such as tetrahydrofuran, dioxin, or nitrile selected from acetonitrile and benzonitrile.
8. A process as claimed in claim 1, wherein the product is separated by vacuum distillation or solvent extraction.
9. A process as claimed in claim 1, wherein hydrolysis of carbonylation products is carried out with the catalyst selected from the group consisting of acidic catalysts as p-toluene sulphonic acid, or a resin like amberlite, separated by distillation or filtration and reused for hydrolysis.
10. An efficient process for the preparation of 2-hydroxy carboxylic acids substantially as herein describe with reference to examples accompanying this specification.

Documents:

386-delnp-2004-abstract.pdf

386-DELNP-2004-Claims-(20-04-2009).pdf

386-delnp-2004-claims.pdf

386-DELNP-2004-Correspondence-Others-(06-05-2009).pdf

386-DELNP-2004-Correspondence-Others-(20-04-2009).pdf

386-delnp-2004-correspondence-others.pdf

386-DELNP-2004-Description (Complete)-(20-04-2009).pdf

386-delnp-2004-description (complete).pdf

386-DELNP-2004-Form-1-(20-04-2009).pdf

386-delnp-2004-form-1.pdf

386-delnp-2004-form-18.pdf

386-DELNP-2004-Form-2-(20-04-2009).pdf

386-delnp-2004-form-2.pdf

386-delnp-2004-form-3.pdf

386-delnp-2004-form-5.pdf

386-DELNP-2004-Petition-137-(06-05-2009).pdf


Patent Number 234310
Indian Patent Application Number 386/DELNP/2004
PG Journal Number 25/2009
Publication Date 19-Jun-2009
Grant Date 20-May-2009
Date of Filing 20-Feb-2004
Name of Patentee COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI-110001, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 RAGHUNATH VITTHAL CHAUDHARI NATIONAL CHEMICAL LABORATARY, PUNE, INDIA.
2 SUNIL SOPANA TONDE NATIONAL CHEMICAL LABORATARY, PUNE, INDIA
PCT International Classification Number NA
PCT International Application Number PCT/IB03/06202
PCT International Filing date 2003-12-26
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 PCT/IB03/06202 2003-12-26 PCT