Title of Invention

A PROCESS FOR THE MANUFACTURE OF 4, 4-DISUBSTITUTED 5-METHYLENE-1,3-DIOXOLAN-2-ONES

Abstract A process for the manufacture of 4,4-disubstituted 5-methylene-l,3- dioxolan-2-ones ("cyclocarbonates") of the formula Iwherein Rl and R2 each independently signify a saturated or olefinically- unsaturated aliphatic group or an aromatic group, or Rl and R2 together form tetra- or pentamethylene, by reacting a corresponding 3,3-disubstituted prop-l-yn-3-o1 of the formula HC=C-C(Rl)(R2)-OH (II) with carbon dioxide in the presence of a quaternary ammonium or phosphonium salt as the catalyst comprises using a silver salt as a further catalyst. An alkali metal or quaternary ammonium or phosphonium salt of a carboxylic acid can also be used to increase the catalytic performance of the silver salt catalyst. Moreover, the addition of triphenylphosphine serves to accelerate the reaction to some extent. The silver salts used catalyze this process for the manufacture of cyclocarbonates significantly better than the copper salts previously used for this iurpose. The advantages of the process in accordance with the invention wnlch accrue are the much smaller amounts of catalyst required, significantly shorter reaction times and less drastic reaction conditions for the shorter reaction time. The thus-manufactured cyclocarbonates are valuable intermediates for the production of polymerisates and other useful substances, e.g. dyestuffs and carotenoids.
Full Text The present invention is concerned with an improved process for the manufacture of cyclic carbonates (cyclocarbonates) from prop-l-yn-3-ols and carbon dioxide in the presence of catalysts. These cyclocarbonates, of which the structurally simplest member is 4,4-dimethyl-5-methylene-l,3-dioxolan-2-one (also known itself as "cyclocarbonate"), are valuable intermediates for the production of polymerisates and other useful substances, e.g. dyestuffs and carotenoids.
Various processes for the manufacture of cyclocarbonates, i.e. 4,4-disubstituted 5-methylene-l,3-dioxolan-2-ones of the general formula

with carbon dioxide, have become known from the scientific literature. Thus, inter alia, copper salts, especially copper halides, e.g. copper(II) chloride or copper(I) iodide, or copper(II) acetate [see German Patent 1,098,953, Synthesis 1981, 958-959 and European Patent Publication (EP) 175 241], diacetonitrilopalladium dichloride (N. Yanagihara et al., 52nd National Meeting of the Chemical Society of Japan, Kyoto April 1986, Abstr. No. 4W 15), ruthenium trichloride trihydrate together with triethylamine [Tetr. Lett. 27, No. 14,1573-1574 (1986)], dicyclopentadienylcobalt, also together with triethylamine [Bull. Chem. Soc. Japan £0, 1204-1206 (1987)3, as well as tributylphosphine [Tetr. Lett. 3J), No. 30, 3981-3982 (1989)] have been
Pa/Ul 18.7.1997

used as catalysts. It has not previously been known that silver salts also catalyze this reaction.
It has now been found that the above reaction, which leads to the 4,4-disubstituted 5-methylene-l,3-dioxolan-2-ones of general formula I, can also be catalyzed ny silver salts, with a quanternary ammonium or phosphonium salt also being used as a further catalyst - as proposed in EP 175 241. In contrast to the teaching of EP 175 241 a tertiary base is not used as an additional catalyst for this process, or its use is superfluous. In principle, the present invention differs from that of EP 175 241 in that a silver salt is used as the catalyst instead of a copper salt.
Accordingly the present invention relates to a process for the manufacture of 4, 4-disubstituted 5-methylene-1,3- dioxolan-2-ones of the general formula

wherein R1 and R2 each independently signify a saturated or oletinically-
1 0
unsaturated aliphatic group or an aromatic group, or R and R together form term¬or pentamethylene, by reacting a corresponding 3,3-disubstituted prop-l-yn-3-ol of the general formula:


with carbon dioxide in the presence of a quaternary ammonium or phosphonium salt as the catalyst, which process comprises using a silver salt as an additional catalyst, whereby per mol of the 3,3-disubstituted prop- l-yn-3-ol of formula II 0.05 to 0.3 mol% quaternary ammonium salt or phosphonium salt catalyst and 0.05 to 0.3 mol% silver salt catalyst are used, and the reaction is effected under a carbon dioxide pressure of 1 bar to 30 bar (100 kPa to 3000 kPa) and in a temperature range of 25°C to 100°C.

In the above definition of the process in accordance with the invention there is to be understood under the term "a saturated aliphatic group" especially alkyl groups with 1 to 16 carbon atoms, which can be not only straight-chain but also (from C3) branched. Also, the "olefinically-unsaturated aliphatic group" (an alkenyl group) contains especially up to 16 carbon atoms and can be straight-chain or branched. Moreover, this group can be mono- or multiply unsaturated, and several double bonds can be conjugated or non-conjugated. Examples of these alkyl and alkenyl groups are methyl, ethyl, isopropyl, isobutyl, tert.butyl and 4,8-dimethyl-nonyl and, respectively, vinyl, 1-propenyl, allyl, 4-methyl-3-pentenyl, 4,8-dimethyl-l,7-nonadienyl and 4,8-dimethyl-l,3,7-nonatrienyl. As the "aromatic group" there comes into consideration especially phenyl or naphthyl, each of which is optionally substituted, for example with one or more (same or different) Ci-4-alkyl and C2-4-alkenyl groups and halogen atoms. Phenyl, p-toluyl and naphthyl are examples of the aromatic groups.
When R1 and R2 together signify tetra- or pentamethylene, then a cyclopentane or cyclohexane ring is present together with the carbon atom to which R1 and R2 are attached.
In principle, all silver salts such as, for example, silver acetate, silver sulphate, silver orthophosphate, silver oxide and silver carbonate are suitable for use accordance with the invention. Silver acetate or silver sulphate is preferably used as the silver salt catalyst.
A quaternary ammonium or phosphonium salt is also used as a catalyst in the process in accordance with the invention. This salt conveniently has the general formula

wherein each R3 independently signifies Ci-6-alkyl, Cs-7-cycloalkyl, aryl-Ci-4-alkyl or aryl and Hal signifies halogen.

In this definition any alkyl group or any alkylene part of the aryl-Ci-4-alkyl group can be straight-chain or branched. Under the term "aryl" (as such or as part of the aryl-Ci-4-alkyl group) there are to be understood especially phenyl and naphthyl, with such a group being unsubstituted or substituted, conveniently with one or more (same or different) Ci-4-alkyl and C2-4-alkenyl groups and halogen atoms. Preferably, any Ci-6-alkyl is methyl, ethyl, isopropyl, n-butyl or hexyl, any Cs-7-cycloalkyl is cyclopentyl or cyclohexyl, any aryl-Ci-4-alkyl is benzyl, and, respectively, any aryl is unsubstituted phenyl or naphthyl. Hal is preferably chlorine or bromine. Especially preferred examples of quaternary ammonium salts of formula Ilia are tetramethylammonium chloride, tetraethylammonium chloride, tetraethylammonium bromide and benzyltrimethylammonium chloride, and especially preferred examples of quaternary phosphonium salts of formula Illb are tetrabutylphosphonium bromide, tetraphenylphosphonium chloride and tetraphenylphosphonium bromide.
The carbon dioxide used in the process in accordance with the invention is gaseous carbon dioxide, which is conveniently introduced into the reaction vessel, suitably a pressure autoclave, which already contains the remaining reaction partners. An increase in the carbon dioxide pressure above normal pressure increases the reaction velocity. Therefore, the process is conveniently carried out under a carbon dioxide pressure which lies above 1 bar (100 kPa), preferably in the range of about 1 bar to about 30 bar (about 100 kPa to about 3000 kPa). When silver acetate is used as the silver salt catalyst, the preferred pressure lies in the range of about 15 bar to about 25 bar (about 1500 kPa) to about 2500 kPa).
Furthermore, the process in accordance with the invention can be carried out in an inert solvent if desired. For this purpose there is generally suitable a polar protic or aprotic solvent, especially an aliphatic hydrocarbon, e.g. n-hexane; an aliphatic ether, e.g. tert.butyl methyl ether; an aliphatic ketone, e.g. 2-methylbutan-3-one; an aliphatic amide, e.g. dimethylformamide; or an aromatic hydrocarbon, e.g. toluene. Aliphatic and aromatic hydrocarbons as well as aliphatic ethers are preferred solvents. In general, the use of a solvent is indicated when the educt and/or the product is/are solid under the reaction conditions (since the respective melting point(s) is/are too high). Unless necessitated because of insufficient

solubility of the educt and/or of the product, the process in accordance with the invention is preferably carried out without the use of a solvent.
With respect to the ratios, there are conveniently used per mol of educt of formula II about 0.05 to about 0.3 mol% of silver salt catalyst and about 0.05 to about 0.3 mol% of onium salt catalyst (quaternary ammonium salt of formula Ilia and/or quaternary phosphonium salt of formula Illb).
The process in accordance with the invention is conveniently effected in the temperature range of about 25°C (i.e. at room temperature) to about 100°C.
The catalytic performance of the various silver salts is different. It has further been found in connection with the present invention that the performance of the silver salts which have a rather low catalytic activity, such as, for example, silver orthophosphate, silver oxide and silver carbonate, can be increased by the addition of an alkali metal or quaternary ammonium or phosphonium salt of a carboxylic acid, with the respective quaternary ammonium or phosphonium ion being especially the aforementioned and defined ion (R3)4N+ or (R3)4P+, respectively. For this purpose, an about equimolar amount of the carboxylic acid salt with respect to the amount of silver salt is suitably added. Examples of carboxylic acid salts which come into consideration are sodium acetate, potassium monoethyl malonate, disodium maleate as well as tetraethylammonium acetate. The alkali metal and quaternary ammonium and phosphonium acetates are preferred.
A further feature of the present invention comprises also carrying out the process in the presence of triphenylphosphine. The addition of triphenylphosphine serves to accelerate the reaction somewhat and is accordingly advantageous. Conveniently, up to about 0.2 mol% of triphenylphosphine is conveniently used per mol of educt of formula II.
In general, the process in accordance with the invention can be performed as a continuous procedure or as a one-pot process (discontinuously).

The working up of the mixture obtained after completion of the reaction in order to isolate the desired 4,4-disubstituted 5-methylene-l,3-dioxolan-2-one of formula I can be effected in a manner known per se. It has been found to be especially practical to obtain the cyclocarbonate from the mixture by fractional distillation. In most cases the catalyst-containing residues can be used for further reaction batches or separated out into the components which can then be reused.
In the case of unstable cyclocarbonates the purification can be effected by chromatography.
The advantage of the process in accordance with the invention over previously known processes for the manufacture of cyclocarbonates is primarily the fact that the silver salts catalyze the respective reaction significantly better that, for example, the copper salts. This means that the reaction is catalyzed by much smaller amounts of catalyst, the reaction time is significantly shorter and less drastic reaction conditions are required for the beneficial reaction time.
The invention is illustrated by the following Examples:
Example 1
Manufacture of 4.4-dimethyl-5-methylene-1.3-dioxolan-2-one
54.68 g (0.65 mol) of 2-methyl-3-butyn-2-ol are placed in a steel autoclave fitted with a manometer, thermometer, safety valve and connection for carbon dioxide gasification. 107 mg (0.41 mmol, 0.063 mol%) of triphenylphosphine, 68 mg (0.41 mmol, 0.063 mol%) of silver acetate as well as 137 mg (0.81 mmol, 0.125 mol%) of tetraethylammonium chloride are added thereto. Then, the autoclave is closed and flushed with carbon dioxide by introducing carbon dioxide up to a pressure of about 20 bar (2000 kPa) with disconnected stirrer and subsequently again releasing pressure; the cycle pressurization and de-pressurization is carried out three times.
Subsequently, pressurization is carried out to 15 bar (1500 kPa) of carbon dioxide and the reaction mixture is heated to 80°C within about

20 minutes while stirring. When the temperature has reached 80°C, the internal pressure is increased to about 20 bar (2000 kPa). The mixture is stirred further at 20 bar (2000 kPa) and 80°C. After 3 hours the pressure is reduced to 5 bar (500 kPa) and the temperature is lowered to 40°C. Once the internal temperature has reached 40°C, pressure is carefully released to normal pressure. (A large amount of carbon dioxide dissolves in the product under pressure, so that the pressure must accordingly be reduced very slowly in order to prevent foaming of the reaction mixture.) Since the melting point of the thus-produced cyclocarbonate exceeds 30°C, it need not be cooled to room temperature.
The mixture is then transferred into a distillation apparatus in which it is fractionated by vacuum distillation. The internal temperature is increased initially to 40°C and at the same time the apparatus is carefully evacuated. The still partially dissolved carbon dioxide thereby bubbles off. After the apparatus has been evacuated to about 10 mbar (1 kPa) the temperature of the oil bath is increased slowly to 100°C. Thereby, the product begins to distil. Head temperature 67-69°C, pressure 12 mbar (1.2 kPa).
After completion of the distillation there remains behind a dark residue, which is dissolved in methylene chloride and discarded.
In this manner there are obtained 78.59 g (98.66% content) of 4,4-dimethyl-5-methylene-l,3-dioxolan-2-one; the yield is 93.1% based on the methylbutynol used.
Example 2
Manufacture of 4-ethvl-4-methvl-5-methylene-1.3-dioxolan-2-one
According to the methodology described in Example 1 and starting from 63.79 g (0.65 mol) of 3-methyl-l-pentyn-3-ol there are obtained 74.54 g (99.99% content) of 4-ethyl-4-methyl-5-methylene-l,3-dioxolan-2-one; the yield is 80.67% based on the methylpentynol used.

Example 3
Manufacture of 4-methvl-4-(4-methvl-3-pentenyl)-5-methylene-1.3-dioxolan-2-one
According to the methodology described in Example 1, but with a heating period of 8 hours at 20 bar (2000 kPa) and 80°C, and starting from 68.51 g (0.45 mol) of 3,7-dimethyl-oct-l-yn-6-en-3-ol (dehydrolinalool) there are obtained 69.41 g (97.79% content) of 4-methyl-4-(4-methyl-3-pentenyl)-5-methylene-l,3-dioxolan-2-one; the yield is 76.9% based on the dehydrolinalool used.
Example 4
r
Manufacture of 4-methvlene-1.3-dioxa-spiro-f4.51-decan-2-one
According to the methodology described in Example 1, but with a heating period of 5 hours at 20 bar (2000 kPa) and 80°C, and starting from 80.82 g (0.65 mol) of 1-ethynyl-cyclohexanol there are obtained 78.59 g (99.99% content) of 4-methylene-l,3-dioxa-spiro-[4.5]-decan-2-one; the yield is 71.2% based on the ethynylcyclohexanol used.
Example 5
Manufacture of 4-methyl-4-(2-methyl-propyl)-5-methylene-1.3-dioxolan-2-one
According to the methodology described in Example 1, but with a heating period of 8 hours at 20 bar (2000 kPa) and 80°C, and starting from 70.0 g (0.549 mol) of 3,5-dimethyl-hex-l-yn-3-ol there are obtained 60.15 g (99.7% content) of 4-methyl-4-(2-methyl-propyl)-5-methylene-l,3-dioxolan-2-one; the yield is 62.17% based on the 3,5-dimethyl-hex-l-yn-3-ol used.
Example 6
Manufacture of 4-methvl-5-methvlene-4-vinyl-1.3-dioxolan-2-one
According to the methodology described in Example 1, but with a heating period of 5 hours at 20 bar (2000 kPa) and 80°C, and starting from

85.45 g (0.800 mol) of 3-methyl-pent-l-en-4-yn-3-ol there are obtained 86.23 g (98.4% content) of 4-methyl-5-methylene-4-vinyl-l,3-dioxolan-2-one; the yield is 75.7% based on the 3-methyl-pent-l-yn-4-en-3-ol used.
Example 7
Manufacture of 4.4-diethyl-5-methylene- 1.3-dioxolan-2-one
According to the methodology described in Example 1, but using 0.25 mol% triphenylphosphine, 0.25 mol% silver acetate and 0.5 mol% tetraethylammonium chloride and starting from 70.81 g (0.625 mol) of 3-ethyl-l-pentyn-3-ol there are obtained after heating at 20 bar (2000 kPa) and 80°C for 21 hours, 78.13 g (96.5% content) of 4,4-diethyl-5-methylene-l,3-dioxolan-2-one; the yield is 77.2% based on 3-ethyl-l-pentyn-3-ol used.
Example 8
Manufacture of 4-methyl-4-isopropvl-5-methylene-1.3-dioxolan-2-one
According to the methodology described in Example 1, but using 0.25 mol% triphenylphosphine, 0.25 mol% silver acetate and 0.5 mol% tetraethylammonium chloride and starting from 65.0 g (0.572 mol) of 2,3-dimethyl-pent-4-yn-3-ol there are obtained after heating at 20 bar (2000 kPa) and 80°C for 4 hours, 73.8 g (98.7% content) of 4-methyl-4-isopropyl-5-methylene-l,3-dioxolan-2-one; the yield is 81.5% based on the 2,3-dimethyl-pent-4-yn-3-ol used.
Example 9
i Manufacture of 4-(4.8-dimethyl-nonvl)-4-methvl-5-methylene-1.3-dioxolan-2-one
According to the methodology described in Example 1, but using 0.25 mol% triphenylphosphine, 0.25 mol% silver acetate and 0.5 mol% i tetraethylammonium chloride and starting from 50.24 g (0.217 mol) of 3,7,11-trimethyl-dodec-l-yn-3-ol there are obtained after heating at 20 bar (2000 kPa) and 80°C for 6 hours, 44.36 g (99% content) of 4-(4,8-dimethyl-nonyl)-4-

methyl-5-methylene-l,3-dioxolan-2-one; the yield is 75.4% based on the 3,7,11-trimethyl-dodec-l-yn-3-ol used.
Example 10
Manufacture of 4-(4.8 dimethyl-nona-1.3.7-trienyl)-4-methyl-5-methylene-1.3-dioxolan-2-one
According to the methodology described in Example 1, but using 0.25 mol% triphenylphosphine, 0.25 mol% silver acetate and 0.5 mol% tetraethylammonium chloride and starting from 77.98 g (0.250 mol) of 3,7,11-trimethyl-dodeca-4,6,10-trien-l-yn-3-ol there are obtained after heating at 25 bar (2500 kPa) and 60°C for 22 hours and purification not by distillation but by column chromatography on silica gel with hexane/diisopropyl ether (17:1) as the eluent 41.4 g (93% content) of 4-(4,8-dimethyl-nona-l,3,7-trienyl)-4-methyl-5-methylene-l,3-dioxolan-2-one; the yield is 58.3% based on the 3,7,11-trimethyl-dodeca-4,6,10-trien-l-yn-3-ol used.
Example 11
Manufacture of various 4.4-disubstituted 5-methylene-1.3-dioxolan-2-ones using silver or copper acetate as the silver/copper salt catalyst: a comparison
The "ethynyl alcohols" 2-methyl-3-butyn-2-ol, 3-methyl-l-pentyn-3-ol, 2-phenyl-3-butyn-2-ol and 1-ethynyl-l-cyclohexanol are reacted in succession with carbon dioxide using silver or copper acetate as the catalyst according to the following general procedure:
650 mmol of ethynyl alcohol are placed in a steel autoclave fitted with a manometer, thermometer, safety valve and connection for carbon dioxide gasification. 0.41 mmol (0.063 mol%) of triphenylphosphine, 0.41 mmol (0.063 mol%) of silver or copper acetate and 0.82 mmol (0.125 mol%) of tetraethylammonium chloride are added thereto. The autoclave is closed and flushed with carbon dioxide. Subsequently, pressurization is carried out to 15 bar (1500 kPa) of carbon dioxide and the reaction mixture is heated to 80°C within about 20 minutes while stirring. Once the reaction temperature has reached 80°C, the internal pressure is increased to 20 bar (2000 kPa).

The mixture is stirred further at 20 bar (2000 kPa) and 80°C and a sample is removed every hour and analyzed by gas chromatography. After completion of the reaction the pressure is released to 5 bar (500 kPa) and the temperature is lowered to 40°C. When the internal temperature has reached 40°C, pressure is released carefully to normal pressure.
The reaction mixture is transferred into a distillation apparatus in which it is fractionated by vacuum distillation. The internal temperature is increased initially to 40°C, during which the apparatus is carefully evacuated. The still partially dissolved carbon dioxide thereby bubbles out. After the apparatus has been evacuated to about 10 mbar (1 kPa) the temperature of the oil bath is increased slowly until the product begins to distil.
After completion of the distillation there remains behind a dark residue, which is dissolved in methylene chloride and discarded.
The results of the analyses are compiled in Table 1 hereinafter:
Table 1
Carboxylation of ethynyl alcohols under catalysis by silver or copper acetate
rAgOCOC%or Cu(OCOCH^21


Example 12
Manufacture of 4.4-dimethvl-5-methylene-1.3-dioxolan-2-one under various reaction conditions
2-Methyl-3-butyn-2-ol was reacted with carbon dioxide (CO2) under catalysis by silver acetate or copper acetate according to the procedure of Example 11. The process was carried out once under standard conditions [at 80°C and 20 bar (2000 kPa) CO2 pressure], once under normal pressure [at 80°C and 1 bar (100 kPa) CO2 pressure] and once at room temperature [at 250C and 20 bar (2000 kPa) CO2 pressure]. The results are compiled in Table 2 hereinafter:
Table 2
Carboxylation at various reaction temperature and pressures

*In order to obtain an adequate reaction velocity under these reaction conditions the concentration of the catalyst mixture was increased to an eight-fold amount of the standard batch.
Example 13
Manufacture of 4.4-dimethyl-5-methylene-1.3-dioxolan-2-one under catalysis bv various silver salt catalysts

2-Methyl-3-butyn-2-ol was reacted with carbon dioxide under catalysis by various silver salt catalysts according to the procedure of Example 11. The results are compiled in Table 3 hereinafter:
Table 3

Example 14
Manufacture of 4.4-dimethvl-5-methylene-1.3-dioxolan-2-one under catalysis by silver nitrate or trifluoroacetate with added carboxylic acid alkali metal salt
2-Methyl-3-butyn-2-ol was reacted with carbon dioxide under catalysis by silver nitrate or trifluoroacetate and added carboxylic acid alkali metal salt according to the procedure of Example 11. The carboxylic acid alkali metal salt was used in each case in an equimolar amount based on the amount of silver salt, and the remaining catalyst components were used in two-fold amounts. The results are compiled in Table 4 hereinafter:

Table 4
Carboxylation under catalysis by silver nitrate or trifluoroacetate and various carboxylic acid alkali metal salt

Example 15
Manufacture of 4.4-dimethvl-5-methvlene-1.3-dioxolan-2-one using various solvents
2-Methyl-3-butyn-2-ol was reacted with carbon dioxide according to the procedure of Example 11, but with the additional use of a solvent. 1.5 ml of solvent were added per gram of methylbutynol. The results are compiled Table 5 hereinafter:




WE CLAIM:
1. A process for the manufacture of 4, 4-disubstituted 5-methylene-l,3- dioxolan-2-ones of the general formula

wherein R and R each independently signify a saturated or olefinically-unsaturated aliphatic group or an aromatic group, or R and R together form term¬or pentamethylene, by reacting a corresponding 3,3-disubstituted prop-l-yn-3-ol of the general formula

with carbon dioxide in the presence of a quaternary ammonium or phosphonium salt as the catalyst, which process comprises using a silver salt as an additional catalyst, whereby per mol of the 3,3-disubstituted prop- l-yn-3-ol of formula II 0.05 to 0.3 mol% quaternary ammonium salt or phosphonium salt catalyst and 0.05 to 0.3 mol% silver salt catalyst are used, and the reaction is effected under a carbon dioxide pressure of 1 bar to 30 bar (100 kPa to 3000 kPa) and in a temperature range of 25°C to 100°C.

2. The process as claimed in claim 1, wherein silver acetate, silver sulphate, silver orthophosphate, silver oxide or silver carbonate, preferably silver acetate or silver sulphate, is used as the silver salt catalyst.
3. The process as claimed in claim 1 or 2, wherein tetramethyl-ammonium chloride, tetraethylammonium chloride tetraethylammonium bromide or benzyltrimethylammonium chloride is used as the quaternary ammonium salt or tetrabutylphosphonium bromide, tetraphenyl-phosphonium chloride or tetraphenylphosphonium bromide is used as the quaternary phosphonium salt.
4. The process as claimed in anyone of claims 1 to 3, wherein in addition an alkali metal or quaternary ammonium or phosphonium salt of a carboxylic acid, preferably sodium acetate, potassium monoethyl malonate, disodium maleate or tetraethylammonium acetate, is used to increase the catalytic performance of the silver salt catalyst.
5. The process as claimed in anyone of claims 1 to 4, wherein the reaction is also carried out in the presence of triphenylphosphine.

6. The process as claimed in claim 5, wherein up to about 0.2 mol% triphenylphosphine is used per mol of educt of formula II.
7. The process according to claim 4, wherein about an equimolar amount of the alkali metal or quaternary ammonium or phosphonium salt of a carboxylic acid relative to the amount of silver salt catalyst is used.

8. A process for the manufacture of 4,4-disubstituted 5-methylene-l,3-dioxolan-2-ones substantially as herein described and exemplified.

Documents:

1841-mas-1997 abstract duplicate.pdf

1841-mas-1997 abstract.pdf

1841-mas-1997 assignment.pdf

1841-mas-1997 claims duplicate.pdf

1841-mas-1997 claims.pdf

1841-mas-1997 correspondence others.pdf

1841-mas-1997 correspondence po.pdf

1841-mas-1997 description (complete) duplicate.pdf

1841-mas-1997 description (complete).pdf

1841-mas-1997 form-13.pdf

1841-mas-1997 form-19.pdf

1841-mas-1997 form-2.pdf

1841-mas-1997 form-26.pdf

1841-mas-1997 form-4.pdf

1841-mas-1997 form-6.pdf

1841-mas-1997 petition.pdf

1841.jpg


Patent Number 207686
Indian Patent Application Number 1841/MAS/1997
PG Journal Number 27/2007
Publication Date 06-Jul-2007
Grant Date 20-Jun-2007
Date of Filing 20-Aug-1997
Name of Patentee M/S. DSM IP ASSETS B V
Applicant Address HET OVERLOON 1, 6411 TE HEERLEN
Inventors:
# Inventor's Name Inventor's Address
1 HANSJORG GRUNDLER 13 THERMENSTRASSE, CH-4310 RHEINFELDEN.
2 HANS-JURGEN HANSEN 101 FROHBURGSTRASSE CH-8006 ZURICH.
PCT International Classification Number C 07 D 317/36
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 96116895.2 1996-10-21 EUROPEAN UNION