Title of Invention

DIOL-FUNCTIONALIZED ANTIOXIDANT AND PROCESS FOR PREPARATION THEREOF

Abstract The present invention relates to a process for preparation of novel based diol functionalized antioxidant of formula I wherein R1 is tert-butyl and R2 is C1 to C8 linear or branched alkyl which comprises of dissolving a compound of formula III wherein R1 is a tertiary butyl group and X is hydrogen, in a dry solvent adding drop-wise solution of bromine in dry carbon tetrachloride, maintaining reaction mixture at a temperature in the range of 80-85°C under inert condition for a span of 4-5 hrs, cooling the reaction mixture to room temperature and evaporating the solvent to obtain the brominated hindered phenol in form of a viscous pale yellow liquid of formula II wherein R1 is a tertiary butyl group and X is Br, reacting the solution of compound of formula II with a diol of formula IV wherein R2 is C1 to C8 linear or branched alkyl along with an inorganic mild base under continuous stirring, refluxing the reaction mixture at a temperature in the range of 85-90 °C for 4-6hrs.
Full Text DIOL-FUNCTIONALIZED ANTIOXIDANT AND PROCESS FOR PREPARATION
THEREOF
Field of the invention
The present invention relates to a novel antioxidant based on functionalized hindered
phenol and the process for the preparation thereof. More particularly it relates to the
compounds of formula I:
(Figure Removed) Formula I
wherein RI is tert-butyl and RI is Ci to Cg linear or branched alkyl. More particularly the
present invention relates to a process of preparation of a antioxidant using compound of
formula II
(Figure Removed) Formula II
wherein RI is a tertiary butyl group and X is Br, which is prepared by the free radical
bromination of compound having general Formula (III)
(Figure Removed) Formula III
wherein RI is a tertiary butyl group and X is hydi ^ • (H).
The invention also relates to synthesis 01 diol derivatives of conventional hindered
phenol antioxidants and useful as condensable monomer for synthesis of many polymers with
in-built antioxidants and the process for the synthesis thereof.
Our co-pending application Sr. No application relates to the novel
antioxidant based on functionalized hindered phenol obtained by the process of this
invention.
• Background of the invention
Diol containing pendant antioxidant and UV absorber groups are gaining much more
importance to stabilize the polyurethane and polyesters against thermal and photochemical
degradation. European Patent No. 627452 Al and 627452 Bl disclose the preparation of
diols with pendant UV absorber moiety and also the preparation of polyurethane and
polyesters from diols containing pendant UV absorbing group.
Most thermoplastic polymers and coating compositions are unstable to the extended
exposure to heat and ultraviolet light source in atmosphere. Thermoplastics and coatings tend
to demonstrate unwanted colour changes and reduced mechanical strength upon exposure to
UV and thermal radiation. The preliminary effect of ultraviolet radiation on polymers is the
formation of free radicals on the polymer chain, which react with atmospheric oxygen to
generate peroxide groups. Furthermore, the decomposition of peroxide group leads to chain
scission and formation of carbonyl groups. Irradiation in absence of oxygen causes the
increase in crosslinking. Ultimately, this reflects on the mechanical properties and the colour
of the polymeric materials. In order to prevent or at least retard the damage caused by these
factors, stabilizers are added to the plastics.
Antioxidants are the compounds, which upon addition to the polymers are capable of
preventing or retarding the reactions of degradation caused by heat and light energy in
presence of oxygen. 2,6-di-tertbutyl-p-cresol is the one of the most important antioxidants,
which is used commercially. There are many patents about the preparation and use of
functional antioxidant in polymers and coatings viz. US4677154, JP5001285A2,
JP6198825A2, JP6025663A2, US5449715, and US6262323.
T. Narayan and I.Grosse, US4677154, June 30, 1987 disclose a stabilizer package for
polyurethane comprising a substituted cresol and another costabilizer. This disclosure relates
to elimination of discoloration in polyurethanes, particularly thermoplastic polyurethanes by
the addition to the reaction mixture from 0.01 to 1 percent by weight, based on the isocyanate
component, a stabilizer package characterized as BHT and a compound selected from
tris(nonyiphenyl) phosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphonite,
bis(2.4-di-t-butylphenyl)pentaerythritol diphosphite, 2,2'-oxamido-bis[ethyl-3(3,5-dit-butyl-
4-hydroxyphenyl)]propionate, disteryl thiodipropionate, triisodecyl phosphite, trilauryl
trithiophosphite, distearyl pentaerythritol, 2,2'-ethylene bis(4,6-di-tertiarylbutylphenol),
octadecyl 3-(3',5'-di-t-butyl-4'-hydroxy phenyl) propionate, 4.4'-thio-bis(2-t-butyl-5-
methylphenol), 4,4 tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, phenothiazine, tris(2,4-di-tbutylphenyl)
phosphite, 4,4'-methylene bis(2,6-di-t-butylphenol). 2.6-di-t-butyldimethylaminomethylphenol
and blends thereof.
Y.SUEMATSU, K.YAMAMOTO, JP5001285A2, Jan. 8. 1993 discloses the
production of natural antioxidant. According to this disclosure, the process results in a natural
antioxidant which gives an oxidation resistance equivalent to that given by well-known
synthetic antioxidants such as BHA or BHT. Various parts of a sunflower, including flowers,
leaves, stems, and roots, dried with hot air, crushed on an ultracentrifuge, and extracted with
an org. common solvent such as hexane or ethyl ether. The resulting extract is concentrated
under a reduced pressure, giving a natural antioxidant.
T.OKINA, K.KATO, H.SUZUKI, JP6198825A2, July 19, 1994 discloses a composite
structure of halogen-containing resin and polyurethane resin. The composite structure of this
disclosure consists of a halogen-containing resin molded object (part) and the polyurethane
resin molded object (part) coming into contact with or coming close to the halogencontaining
molded object (part), 0.01-20 pts. wt. of an oxidation inhibitor is contained in the
polyurethane resin compsn. at the time of the molding of the polyurethane resin molded
object with respect to 100 pts.wt. of polyol contained in the polyurethane resin compsn. This
oxidation inhibitor is composed of at least one of a phenolic oxidation inhibitor (BHT, BHA),
a phosphorous oxidation inhibitor and a sulfur oxidation inhibitor.
A.NISH1NA, S.HASHIMOTO, JP6025663A2, Feb. 1, 1994 discloses an antioxidant
obtained by using torachrysone represented by a specified formula as an effective component.
This antioxidant contains torachrysone of the formula as an effective component.
Torachrysone (l,8-dihydroxy-2-acetyl-3-methyl-6-methoxynaphthalene) is prepared by
purifying an extract from the seed of cassia tora L. or a herb such as Rheirhizoma. This
antioxidant is used in an amount of 10-10000ppm (in terms of torachrysone) based on the
objective substance, e.g. food, cosmetic or medicine. It may be optionally used in
combination with another additive such as tocopherol. It has an antioxidant power much
ronger than that of a natural antioxidant such as tocopherol or L- ascorbic acid or a
synthetic antioxidant such as BHA or BHT.
K. Plochocka et al., US5449715, Sept. 12, 1995 discloses a colorless, non-toxic, stabilized
aqueous solution of a C1-C5 alkyl vinyl ether and maleic acid copolymers. The product
comprises a colorless, stabilized aqueous solution of a Cl -C5 alkyl vinyl ether and maleic
acid copolymer which includes about 100 to 1,000 ppm of an additive mixture of (a) about
30-70% by weight of ethylenediaminetetraacetic acid (EDTA) or its salts, such as the
disodium, trisodium, tetrasodium or disodium-calcium salts, and (b) about 30-70% by weight
of a secondary additive which is an organic antioxidant and/or free radical scavenger selected
from t-butylhydroquinone, propyl gallate, butylated hydroxy-anisole (BHA), butylated
hydroxy-toluene (BHT), 4-hydroxymethyl-2,6-di-tert-butylphenol, 2,4,5-trihydroxybutyrophenone
(THBP) and N,N-diethylhydroxylamine, said stabilized solution exhibiting a
retention of at least about 85-90% of its original viscosity after 3 months. Preferably, the
solution is prepared by hydrolyzing the corresponding anhydride in the presence of said
additive mixture.
Elder, Sherri et al, US6262323, July 17, 2001 discloses polymerization inhibition of
isoprene. In one preferred embodiment, the polymerization inhibiting composition includes
phenylenediamine (PDA), butylated hydroxytoluene (BHT) and N,N'-diethylhydroxylamine
(DEHA).
Monomeric and low molecular weight antioxidants are having limitation to their
utility owing to their properties of migration and leaching. This phenomenon could lead to
uneven distribution of antioxidants within the polymeric matrix. Leaching could be even
more harmful as the loss of antioxidants from the polymer matrix could lead to extensive
thermal and photo-degradation of the substrate. Therefore, in order to prevent the phenomena
of migration and leaching, the antioxidants with polymerizing ability are being developed.
This particular class of stabilizers would have even distribution within the polymer matrix
and also they overcome the phenomena of migration and leaching.
Objects of the invention
The objective of the present invention is therefore, to provide a novel
polycondensable diol functionalized antioxidant and the process for the preparation thereof
which can fulfill the above-mentioned prerequisites of a stabilizer.
Summary of the invention
The present invention providesm®ovel dfal functionalized antioxidant of formula I
CH2-N-fR2-OH),
Formula I
wherein RI is tert-butyl and RZ is Ci to Cg linear or branched alkyl.
(Figure Removed) The present invention also provides process for the preparation of diol-functionalized
antioxidant of the formula I
(Figure Removed) Formula I
wherein RI is tert-bulyl and R2 is Ci to Cg linear or branched alkyl which comprises of
dissolving a compound of formula III
Formula III
wherein RI is a tertiary butyl group and X is hydrogen, in a dry solvent adding drop-wise
solution of bromine in dry carbon tetrachloride, maintaining reaction mixture at a temperature
in the range of 80 - 85 °C under inert condition for a span of 4-5 hours, cooling the reaction
mixture to room temperature and evaporating the solvent to obtain the brominated hindered
phenol in the form of a viscous pale yellow liquid, of formula II
(Figure Removed) Formula II
wherein RI is a tertiary butyl group and X is Br, reacting the solution of compound of
formula II with a diol of formula IV
(Figure Removed) wherein R2 is Ci to Cg linear or branched alkyl along with an inorganic mild base under
continuous stirring, refluxing the reaction mixture at a temperature in the range of 85 - 90 °C
for 4-6 hrs to obtain fine crystals of the diol functionalized antioxidant of formula (I).
In one of the embodiments of the present invention, the neutral organic solvent used
for dissolving the compound having formula (III) is selected from chlorinated solvent like,
carbon tetrachloride, chloroform, chlorobenzene and dichloromethane.
In another embodiments the bromination of compound of formula (III) is achieved by
using liquid bromine.
In still another embodiment the organic solvent selected for dissolving the compound
having general formula (II) is selected from benzene, toluene, xylene, carbon tetrachloride,
dichloromethane and tetrahydrofuran.
In still another embodiment the diol is selected from Ci to Cg linear or branched alkyl
ethanolamine.
In still another embodiment the mild inorganic base is selected from carbonates and
bi-carbonates of alkali metals such as potassium carbonate, sodium carbonate, calcium
carbonate, sodium bicarbonate and potassium bicarbonate.
Detailed description of the invention
The present invention also provides process for the preparation of diol-functionalized
antioxidant which comprises of dissolving a compound of formula III
(Figure Removed) wherein Rt is a tertiary butyl group and X is hydrogen, in a dry solvent adding drop-wise
solution of bromine in dry carbon tetrachloride, maintaining reaction mixture at a temperature
in the range of 80 - 85 °C under inert condition for a span of 4-5 hours, cooling the reaction
mixture to room temperature and evaporating the solvent to obtain the brominated hindered
phenol in the form of a viscous pale yellow liquid, of formula II
(Figure Removed) wherein RI is a tertiary butyl group and X is Br, reacting the solution of compound of
formula (II) with a diol of general formula (IV)
(Figure Removed) wherein Rj is Ci to Cg linear or branched alkyl along with an inorganic mild base under
continuous stirring, refluxing the reaction mixture at a temperature in the range of 85 - 90 °C
for 4-6 hrs to obtain fine crystals of the diol finctionalized antioxidant of formula (I).
The neutral organic solvent used for dissolving the compound having formula (III) is
selected from chlorinated solvent like, carbon tetrachloride, chloroform, chlorobenzene and
dichloromethane. The bromination of compound of formula (III) is preferably achieved by
using liquid bromine.
The organic solvent selected for dissolving the compound having general formula (II)
is selected from benzene, toluene, xylene, carbon tetrachloride, dichloromethane and
tetrahydrofuran. The diol itself is preferably selected from Ci to C8 linear or branched alkyl
ethanolamine.
The mild inorganic base is selected from carbonates and bi-carbonates of alkali metals
such as potassium carbonate, sodium carbonate, calcium carbonate, sodium bicarbonate and
potassium bicarbonate.
The following examples describe the process for the preparation of the diolfucntionalized
antioxidants, which are illustrative only and should not be constructed, to the
scope of the present invention in any manner.
Example 1: Synthesis of 3,5-di-terT-butyl-4-hydroxy benzyl bromide
3,5-di-tert-butyl-4-hydroxy benzyl bromide was prepared from the bromination of
2,6-di-tert-butyl-4-methyl phenol. In a 250 ml three-necked round bottomed flask, 2.5 gm of
2,6-di-tert-butyl-4-methyl phenol and dissolved in 25 ml of dry carbon tetrachloride. In a
separate conical flask, 0.3 ml of bromine was dissolved in 25 ml of dry carbon tetrachloride
and solution was transferred to a cylindrical funnel with pressure equalizing tube. Threenecked
round-bottomed flask containing solution of 2,6-di-ter/-butyl-4-methyl phenol was
kept in oil-bath at 85 °C. Nitrogen was bubbled through the solution for creating inert
atmosphere. Cylindrical funnel containing bromine solution was mounted on the threenecked
round-bottomed flask. Solution in the flask was continuously stirred with the help of
magnetic stirrer. Bromine solution was added, drop-by-drop, from funnel to the flask for a
span of 4-5 hours till all the solution was poured out. After that heating was stopped and the
final reaction mixture was allowed to cool at room temperature. Finally the product obtained
was a viscous yellow liquid and was absolutely pure. The yield of 3,5-di-ter/-butyl-4-hydroxy
benzyl bromide was 3.03 gm (90 %)
Example 2: Synthesis of 2,6-di-tert-butyl-4-(bis(2-hydroxyethyl)aminomethyI)phenol
In a round bottom flask taken 2.24 gm of 3,5-ditertbutyl-4-hydroxy benzyl bromide
and 0.6 ml of N, N-diethanol amine and dissolved in 100 mL of benzene. The reaction
mixture was refluxed with constant stirring at 75-80 °C for 6 hrs. The product was
crystallized out in the form of colorless needles. The solvent was decanted, crystals were
filtered off and washed with pure benzene. The yield of the product is 1.43 gm (64 %).
Product was identified by !H-NMR and FT-IR spectroscopic techniques.
Example 3: Synthesis of 2,6-di-ter*-butyl-4-(bis(2-hydroxy isopropyl)aminomethyl)
phenol
In a round bottom flask taken 2.5 gm of 3,5-di-tert-butyl-4-hydroxy benzyl bromide
and 0.8 ml of N, N-diisopropanol amine and dissolved in 100 mL of benzene. The reaction?
mixture was refluxed with constant stirring at 75-80 °C for 6 hrs. The product crystallized out
in form of colorless needles. The solvent was decanted, crystals were filtered off and washed
with pure benzene. The yield of the product is 2.06 gm (68 %). Product was identified by H
NMR and FT-IR spectroscopic techniques.
The process of the present invention has four distinct merits:
1) The process is highly economic.
2) The process comprises of commonly available organic reagents and mild reaction
conditions.
3) High yield (65 %) can be achieved very easily.
4) The process involves synthesis of novel diol-functionalized antioxidants from readily
available conventional hindered phenols by very short and facile route with simple via
moderate reaction conditions.



We claim:
1. A novel diol functionalized antioxidant of formula I
(Figure Removed) Formula I
wherein RI is tert-butyl and R2 is Ci to Cg linear or branched alkyl.
2. A process for the preparation of diol-functionalized antioxidant of the formula I below
(Figure Removed)Formula I
wherein Rt is ter/-butyl and Ra is Ci to C8 linear or branched alkyi said process comprising
dissolving a compound of formula III
(Figure Removed)wherein RI is a tertiary butyl group and X is hydrogen, in a dry solvent, adding drop-wise
solution of bromine in dry carbon tetrachloride, maintaining reaction mixture at a temperature
in the range of 80 - 85 °C under inert condition for a span of 4-5 hours, cooling the reaction
mixture to room temperature and evaporating the solvent to obtain the brominated hindered
phenol in the form of a viscous pale yellow liquid, of formula II
(Figure Removed)
wherein R1 is a tertiary butyl group and X is Br, reacting the solution of compound of formula II with a diol of general formula IV.
(Formula Removed)
wherein R2 is C1 to C8 linear or branched alkyl along with an inorganic mild base under continuous stirring, refluxing, the reaction mixture at a temperature in the range of 85-90°C for 4-6 hrs to obtain fine crystals of the diol functionalized antioxidant of formula I
3. A process as claimed in claim 2 wherein the dry solvent used for dissolving compound
of formula III is a chlorinated solvent.
4. A process as claimed in claim 3 wherein the chlorinated solvent is selected from the group consisting of carbon tetrachloride, chloroform, chlorobenze and dichloromethane.
5. A process as claimed in claim 2 wherein the bromination of compound of formula III is carried out using liquid bromine.
6. A process as claimed in claim 2 wherein the organic solvent selected for dissolving the compound of formula II is selected from thr group consisting of benzene . toluene, xylene, carbon tetrachloride, dichloromethane and tetrahydrofuran.
7. A process as claimed in claim 2 wherein the diol is selected from C1 to C2 linear or branched alkyl ethanolamine.
8. A process as claimed in claim 2 wherein the mild inorganic base is selected from carbonates and bi-carbonates of alkali metals.
9. A process as claimed in claim 8 wherein the carbonates and bi-carbonates of alkali metals are selected from the group consisting of potassium carbonate, sodium carbonate, calcium carbonate, sodium bicarbonate and potassium bicarbonate.
10. A novel diol functionalized antioxidant substantially as herein describe with reference to examples accompanying this specification.

Documents:

252-DEL-2003-Abstract-(20-11-2008).pdf

252-del-2003-abstract.pdf

252-DEL-2003-Claims-(20-11-2008).pdf

252-del-2003-claims.pdf

252-del-2003-correspondence-others.pdf

252-del-2003-correspondence-po.pdf

252-del-2003-description (complete).pdf

252-del-2003-form-1.pdf

252-del-2003-form-18.pdf

252-del-2003-form-2.pdf

252-DEL-2003-Form-3-(20-11-2008).pdf

252-del-2003-form-3.pdf

252-DEL-2003-Petition 137-(20-11-2008).pdf

abstract.jpg


Patent Number 244619
Indian Patent Application Number 252/DEL/2003
PG Journal Number 51/2010
Publication Date 17-Dec-2010
Grant Date 13-Dec-2010
Date of Filing 07-Mar-2003
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI-110001
Inventors:
# Inventor's Name Inventor's Address
1 SHROJAL MOHITKUMAR DESAI NATIONAL CHEMICAL LABORATORY, PUNE-411008, MAHARASTRA, INDIA.
2 RAJ PAL SINGH NATIONAL CHEMICAL LABORATORY, PUNE-411008, MAHARASTRA, INDIA.
3 SHAILENDRA SINGH SOLANKY NATIONAL CHEMICAL LABORATORY, PUNE-411008, MAHARASTRA, INDIA.
PCT International Classification Number C07B 41/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA