Title of Invention	A MONOMER PYROMELLITIC DIANHYDRIDE GLYCEROL DIMETHACRYLATE (PMGDM)
Abstract	A process for the preparation of '1,24,5-benezene tetracarboxylic acid 1,4-bis((2-methyl-1-oxo-2-propenyl)oxy)-1-(((2-methyl-1-oxo-2-propenyl)oxy)methyl)esthyl)ester'(PMGDM) comprising reacting 1-2 moles 1,2,4,5 benzene tetracarboxylic acid dianhydride with glycerol dimethacrylate in the presence of a base catalyst and a stabilizer in an inert solvent and at a temperature in the range of 40-50ºC for a period of 4-8 hours.

Title of Invention

A MONOMER PYROMELLITIC DIANHYDRIDE GLYCEROL DIMETHACRYLATE (PMGDM)

Abstract

A process for the preparation of '1,24,5-benezene tetracarboxylic acid 1,4-bis((2-methyl-1-oxo-2-propenyl)oxy)-1-(((2-methyl-1-oxo-2-propenyl)oxy)methyl)esthyl)ester'(PMGDM) comprising reacting 1-2 moles 1,2,4,5 benzene tetracarboxylic acid dianhydride with glycerol dimethacrylate in the presence of a base catalyst and a stabilizer in an inert solvent and at a temperature in the range of 40-50ºC for a period of 4-8 hours.

Full Text	FIELD OF THE IWVEWTIOW This invention relates to a process for the synthesis of a monomer pyromellitic dianhydrlde glycerol dimethacrylate (PMGDM) BACKGROUND OF THE IWVENTIOW Initially, bisphenol A-glycldyl methacrylate (Bis-GMA) resin based bonding agents were used in dentistry. However, due high viscosity of the resin, priming became difficult and bonding agents generally contained a low viscosity priming solution also. The synthesis of acidic monomers such as PMGDM which is used as a solution in an appropriate volatile aprotic solvent was found useful in preparing single solution bonding agents (SSBA). These SSBA's were capable of carrying out the priming and bonding functions together. 1,2,4,5-benzene tetracarboxylic acid 1,4-bis ((20methyH-oxo-2-propenyl) oxy)-1-(((2-m ethyl-1-oxo-2-propenyl) oxy)methyl)ethyl)ester or pyromellitic dian hydride glycerol dimethacrylate (PMGDM) is used as a raw material for some commercial imported bonding agents such as Dentastic Uno, Excite etc. However, It has not yet been synthesized In India and the process technology Is not available. OBJECTS OF THE INVENTION It Is therefore an object of this Invention to propose a process for the preparation of PMGDM These and other objects and advantages of the invention will be apparent from the ensuing description. DESCRIPTION OF THE INVENTION Thus according to this invention is provided a process for the preparation of 1,2,4,5-benzene tetracarboxylic acid 1,4-bis ((2-methyl-1-oxo-2-propenyl) oxy)-1-(((2-methyl-1-oxo-2-propenyl) oxy) methyl)ethyl)ester or pyromellitlc dianhydride glycerol dimethacrylate (PMGDM) with glycerol dimethacrylate (GDM) in a volatile aprotic solvent in the presence of stabilisers. Excess of GDM ensures absence of unreacted toxic dianhydride. In accordance wth this invention, 1-2 moles of pyromellitlc dianhydride is reacted with more than 2-4 moles of glycerol dimethacrylate in the presence of a base catalyst and a stabiliser In a volatile dipolar aprotic solvent and at a temperature in the range of 40-50 ">C for a period of 4-8 hrs. The product is recovered by evaporating off the solvent, preferably In a rotating flash evaporator under vacuum. The preparation of PMGDM is catalysed by tertiary amines such as 2-dimethyl amino ethyl methacrylate or ammonium salts, such as benzyl tri ethyl ammonium chloride, the amount of catalyst added being 1-2 vvt% of the total weight of the reactants. The dipolar volatile aprotic solvent Is selected fi-om methyl ethyl ketone, acetone, diethyl ketone etc., the amount of solvent being enough to dissolve the reactants and form a soluble mix. The stabiliser is such as butylated hydroxy toluene, the amount of stabiliser being 0.05-0.2% by weight of the total weight of the reactants. The final product is stored as such or as a solution in acetone which can fiirther be used in single solution dental adhesives. The Invention will now be explained in greater details with the help of the follovwing non-limiting examples. E?(^mple1; 21.81 gm of pyromellitic dianhydride is reacted with 47.93 gm of glycerol dimethacrylate (GDM) by dissolving in 126.4 mi of an aprotic solvent such as diethyl ketone or dimethyl ketone or methyl ethyl ketone at 45 Example 2: 10.91 gm of pyromellitic dianhydride is reacted \with 23.97 gm of glycerol dimethacrylate (GDM) by dissolving in 63.21 ml of an aprotic solvent such as diethyl ketone or dimethyl ketone or methyl ethyl ketone at 45 •€ for 5 hours using 0.337 gm of a tertiary amine such as benzyl triethyl ammonium chloride or 2-dlmethylamlnoethyl methacrylate as catalyst and 0.03 gm of butylated hydroxytoluene as stabliser. Excess of GOM ensures absence of unreacted toxic dianhydride. The final product in the solvent is concentrated to appropriate levels for use as monomer in bonding agents. WE CLAIM: 1. A monomer, 1,2,4,5-benzene tetracarboxylic add 1,4-bis((2-methyH-oxo- 2-propenyl)oxy)-1- 2-m ethyl-1-oxo-2-propenyl) oxy)methyl)ethyl)ester' (PWIGDM) of formula I. 2. A process for the preparation of '1,2,4,6-benezene tetracarboxylic acid 1,4-b}s((2-methyl-1-oxo-2-propenyl)oxy)-1-(((2-methyl-1-oxo-2- propenyl)oxy)methyl)ethyl)ester' (PMGDM) in the presence of a base catalyst and a stabilizer in an inert solvent and at a temperature In the range of 40-50 C for a period of 4-8 hours. 3. A process as claimed in claim 2, wherein the said catalyst is selected from tertiary amines such as 2 - dimethyl amino ethyl methacrylate or ammonimum salts such as benzyl triethyl ammonimum chloride. 4. The process as claimed in claim 2, wherein the said catalyst Is added in 1- 2 wt% of the total weight of the reactants. 5. A process as claimed in claim 2, wherein the said solvent is a dipolar aprotic solvent such as methyl ethyl ketone, acetone, diethyl ketone etc, the amount of solvent being enough to dissolve the rectants and form a soluble mix. 6. A process as claimed in claim 2, wherein PMGDM is synthesized in the presence of a stabilizer such as butylated hydroxy toluene, the amount of stabilizer being 0.05-0.2% by weight of the total weight of the reactants. 8. A process as claimed in claim 2, wherein the final product Is stored as such or as a solution In acetone which can further be used in single solution dental adhesives.

Full Text

FIELD OF THE IWVEWTIOW
This invention relates to a process for the synthesis of a monomer pyromellitic dianhydrlde glycerol dimethacrylate (PMGDM)

BACKGROUND OF THE IWVENTIOW
Initially, bisphenol A-glycldyl methacrylate (Bis-GMA) resin based bonding agents were used in dentistry. However, due high viscosity of the resin, priming became difficult and bonding agents generally contained a low viscosity priming solution also. The synthesis of acidic monomers such as PMGDM

which is used as a solution in an appropriate volatile aprotic solvent was found useful in preparing single solution bonding agents (SSBA). These SSBA's were capable of carrying out the priming and bonding functions together.
1,2,4,5-benzene tetracarboxylic acid 1,4-bis ((20methyH-oxo-2-propenyl) oxy)-1-(((2-m ethyl-1-oxo-2-propenyl) oxy)methyl)ethyl)ester or pyromellitic dian hydride glycerol dimethacrylate (PMGDM)

is used as a raw material for some commercial imported bonding agents such as Dentastic Uno, Excite etc. However, It has not yet been synthesized In India and the process technology Is not available.
OBJECTS OF THE INVENTION
It Is therefore an object of this Invention to propose a process for the preparation of PMGDM

These and other objects and advantages of the invention will be apparent from the ensuing description.

DESCRIPTION OF THE INVENTION
Thus according to this invention is provided a process for the preparation of 1,2,4,5-benzene tetracarboxylic acid 1,4-bis ((2-methyl-1-oxo-2-propenyl) oxy)-1-(((2-methyl-1-oxo-2-propenyl) oxy) methyl)ethyl)ester or pyromellitlc dianhydride glycerol dimethacrylate (PMGDM)

with glycerol dimethacrylate (GDM) in a volatile aprotic solvent in the presence of stabilisers. Excess of GDM ensures absence of unreacted toxic dianhydride.
In accordance wth this invention, 1-2 moles of pyromellitlc dianhydride is reacted with more than 2-4 moles of glycerol dimethacrylate in the presence of a base catalyst and a stabiliser In a volatile dipolar aprotic solvent and at a temperature in the range of 40-50 ">C for a period of 4-8 hrs. The product is recovered by evaporating off the solvent, preferably In a rotating flash evaporator under vacuum. The preparation of PMGDM

is catalysed by tertiary amines such as 2-dimethyl amino ethyl methacrylate or ammonium salts, such as benzyl tri ethyl ammonium chloride, the amount of catalyst added being 1-2 vvt% of the total weight of the reactants.
The dipolar volatile aprotic solvent Is selected fi-om methyl ethyl ketone, acetone, diethyl ketone etc., the amount of solvent being enough to dissolve the reactants and form a soluble mix. The stabiliser is such as butylated hydroxy toluene, the amount of stabiliser being 0.05-0.2% by weight of the total weight of the reactants.
The final product is stored as such or as a solution in acetone which can fiirther be used in single solution dental adhesives.
The Invention will now be explained in greater details with the help of the follovwing non-limiting examples.
E?(^mple1;
21.81 gm of pyromellitic dianhydride is reacted with 47.93 gm of glycerol dimethacrylate (GDM) by dissolving in 126.4 mi of an aprotic solvent such as diethyl ketone or dimethyl ketone or methyl ethyl ketone at 45
Example 2:
10.91 gm of pyromellitic dianhydride is reacted \with 23.97 gm of glycerol dimethacrylate (GDM) by dissolving in 63.21 ml of an aprotic solvent such as diethyl ketone or dimethyl ketone or methyl ethyl ketone at 45 •*€ for 5 hours using 0.337 gm of a tertiary amine such as benzyl triethyl ammonium chloride or 2-dlmethylamlnoethyl methacrylate as catalyst and 0.03 gm of butylated hydroxytoluene as stabliser. Excess of GOM ensures absence of unreacted toxic dianhydride. The final product in the solvent is concentrated to appropriate levels for use as monomer in bonding agents.

WE CLAIM:
1. A monomer, 1,2,4,5-benzene tetracarboxylic add 1,4-bis((2-methyH-oxo-
2-propenyl)oxy)-1- 2-m ethyl-1-oxo-2-propenyl) oxy)methyl)ethyl)ester'
(PWIGDM) of formula I.

2. A process for the preparation of '1,2,4,6-benezene tetracarboxylic acid
1,4-b}s((2-methyl-1-oxo-2-propenyl)oxy)-1-(((2-methyl-1-oxo-2-
propenyl)oxy)methyl)ethyl)ester' (PMGDM)

in the presence of a base catalyst and a stabilizer in an inert solvent and at a temperature In the range of 40-50 *C for a period of 4-8 hours.
3. A process as claimed in claim 2, wherein the said catalyst is selected from
tertiary amines such as 2 - dimethyl amino ethyl methacrylate or
ammonimum salts such as benzyl triethyl ammonimum chloride.
4. The process as claimed in claim 2, wherein the said catalyst Is added in 1-
2 wt% of the total weight of the reactants.
5. A process as claimed in claim 2, wherein the said solvent is a dipolar
aprotic solvent such as methyl ethyl ketone, acetone, diethyl ketone etc,
the amount of solvent being enough to dissolve the rectants and form a
soluble mix.
6. A process as claimed in claim 2, wherein PMGDM

is synthesized in the presence of a stabilizer such as butylated hydroxy toluene, the amount of stabilizer being 0.05-0.2% by weight of the total weight of the reactants.

8. A process as claimed in claim 2, wherein the final product Is stored as such or as a solution In acetone which can further be used in single solution dental adhesives.

Documents:

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391-mas-2003-abstract.pdf

391-mas-2003-claims filed.pdf

391-mas-2003-claims granted.pdf

391-mas-2003-correspondnece-others.pdf

391-mas-2003-correspondnece-po.pdf

391-mas-2003-description(complete)filed.pdf

391-mas-2003-description(complete)granted.pdf

391-mas-2003-description(provisional).pdf

391-mas-2003-form 1.pdf

391-mas-2003-form 26.pdf

391-mas-2003-form 3.pdf

391-mas-2003-form 5.pdf

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Patent Number

214329

Indian Patent Application Number

391/MAS/2003

PG Journal Number

18/2008

Publication Date

02-May-2008

Grant Date

11-Feb-2008

Date of Filing

09-May-2003

Name of Patentee

SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY

Applicant Address

BIOMEDICAL TECHNOLOGY WING, SATELMOND PALACE, THIRUVANANTHAPURAM, PIN -695 012,

Inventors:

#	Inventor's Name	Inventor's Address
1	LIZYMOL PHILIPOSE PAMPADYKANDATHIL	SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY, AN INDIAN INSTITUTE OF NATIONAL IMPORTANCE, SATELMOND PALACE, POOJAPURA, THIRUVANANTHAPURAM -695 - 012.
2	KALLIYANAKRISHNAN VENKATESWARAN	SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY, AN INDIAN INSTITUTE OF NATIONAL IMPORTANCE, SATELMOND PALACE, POOJAPURA, THIRUVANANTHAPURAM -695 - 012.

PCT International Classification Number

A 61K 6/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA