IE49308B1 - Process for manufacturing racemic parahydroxymandelic acid - Google Patents
Process for manufacturing racemic parahydroxymandelic acidInfo
- Publication number
- IE49308B1 IE49308B1 IE2108/79A IE210879A IE49308B1 IE 49308 B1 IE49308 B1 IE 49308B1 IE 2108/79 A IE2108/79 A IE 2108/79A IE 210879 A IE210879 A IE 210879A IE 49308 B1 IE49308 B1 IE 49308B1
- Authority
- IE
- Ireland
- Prior art keywords
- acid
- glyoxylic acid
- phenol
- condensation
- water
- Prior art date
Links
- YHXHKYRQLYQUIH-UHFFFAOYSA-N 4-hydroxymandelic acid Chemical compound OC(=O)C(O)C1=CC=C(O)C=C1 YHXHKYRQLYQUIH-UHFFFAOYSA-N 0.000 title claims abstract description 13
- 238000000034 method Methods 0.000 title claims description 25
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- HHLFWLYXYJOTON-UHFFFAOYSA-N glyoxylic acid Chemical compound OC(=O)C=O HHLFWLYXYJOTON-UHFFFAOYSA-N 0.000 claims abstract description 73
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims abstract description 28
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 5
- HEMHJVSKTPXQMS-UHFFFAOYSA-M sodium hydroxide Inorganic materials [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 30
- 238000009833 condensation Methods 0.000 claims description 16
- 230000005494 condensation Effects 0.000 claims description 16
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 9
- 239000008346 aqueous phase Substances 0.000 claims description 4
- 239000002904 solvent Substances 0.000 claims description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical group C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 3
- 238000000605 extraction Methods 0.000 claims description 3
- 230000003472 neutralizing effect Effects 0.000 claims description 3
- 239000003960 organic solvent Substances 0.000 claims description 2
- 239000012429 reaction media Substances 0.000 claims description 2
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 12
- 239000000243 solution Substances 0.000 description 12
- 239000012299 nitrogen atmosphere Substances 0.000 description 9
- -1 alkali metal salt Chemical class 0.000 description 8
- 235000011121 sodium hydroxide Nutrition 0.000 description 8
- LHGVFZTZFXWLCP-UHFFFAOYSA-N guaiacol Chemical compound COC1=CC=CC=C1O LHGVFZTZFXWLCP-UHFFFAOYSA-N 0.000 description 6
- 239000008188 pellet Substances 0.000 description 6
- 238000003756 stirring Methods 0.000 description 6
- RGHHSNMVTDWUBI-UHFFFAOYSA-N 4-hydroxybenzaldehyde Chemical compound OC1=CC=C(C=O)C=C1 RGHHSNMVTDWUBI-UHFFFAOYSA-N 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- 239000012736 aqueous medium Substances 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 239000001117 sulphuric acid Substances 0.000 description 4
- 235000011149 sulphuric acid Nutrition 0.000 description 4
- 150000007513 acids Chemical class 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 229960001867 guaiacol Drugs 0.000 description 3
- 230000007062 hydrolysis Effects 0.000 description 3
- 238000006460 hydrolysis reaction Methods 0.000 description 3
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 2
- YCIMNLLNPGFGHC-UHFFFAOYSA-N catechol Chemical compound OC1=CC=CC=C1O YCIMNLLNPGFGHC-UHFFFAOYSA-N 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- HFFLGKNGCAIQMO-UHFFFAOYSA-N trichloroacetaldehyde Chemical compound ClC(Cl)(Cl)C=O HFFLGKNGCAIQMO-UHFFFAOYSA-N 0.000 description 2
- RGHMISIYKIHAJW-UHFFFAOYSA-N 3,4-dihydroxymandelic acid Chemical compound OC(=O)C(O)C1=CC=C(O)C(O)=C1 RGHMISIYKIHAJW-UHFFFAOYSA-N 0.000 description 1
- WSGYTJNNHPZFKR-UHFFFAOYSA-N 3-hydroxypropanenitrile Chemical compound OCCC#N WSGYTJNNHPZFKR-UHFFFAOYSA-N 0.000 description 1
- 238000005705 Cannizzaro reaction Methods 0.000 description 1
- AEMRFAOFKBGASW-UHFFFAOYSA-N Glycolic acid Chemical class OCC(O)=O AEMRFAOFKBGASW-UHFFFAOYSA-N 0.000 description 1
- CGQCWMIAEPEHNQ-UHFFFAOYSA-N Vanillylmandelic acid Chemical compound COC1=CC(C(O)C(O)=O)=CC=C1O CGQCWMIAEPEHNQ-UHFFFAOYSA-N 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 150000003934 aromatic aldehydes Chemical class 0.000 description 1
- 244000309464 bull Species 0.000 description 1
- 230000000911 decarboxylating effect Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- MJGFBOZCAJSGQW-UHFFFAOYSA-N mercury sodium Chemical compound [Na].[Hg] MJGFBOZCAJSGQW-UHFFFAOYSA-N 0.000 description 1
- 150000004682 monohydrates Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 229910001023 sodium amalgam Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/347—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups
- C07C51/367—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups by introduction of functional groups containing oxygen only in singly bound form
Abstract
Racemic parahydroxymandelic acid is prepared by condensing glyoxylic acid with an excess of phenol in water in the presence of an alkaline agent, at 30 to 100 DEG C.
Description
The present invention relates to a process for manufacturing racemic parahydroxymandelic acid by the condensation of glyoxylic acid with phenol, in an alkaline medium.
It is known that carbonyl derivatives such as glyoxylic acid or chloral 5 condense in an alkaline aqueous medium on phenol rings substituted or unsubstituted by hydroxyl, alkoxy and/or alkyl groups possessing at least one proton on the para position, to provide racemic arylglycolic acids either directly, or by the hydrolysis of racemic arylthichloromethylcarbinols (Houben-Weyl, phenole 6/lc, pages 10 1022-1058, G. Thieme Verlag Stuttgart, 1976).
Racemic arylglycolic acids are valuable starting materials since it is known how to convert them into aromatic aldehydes (P. Hebert, Bull. Soc. Chim. France, 27, 4th serie, 45-55, 1920). In particular racemic parahydroxymandelic acid provides by decarboxylating oxidation, parahydroxybenzaldehyde (Nagai Shigeki et Coll., Japanese Patent
Application No. 76 128 034).
48308
Racemic parahydroxymandelic acid is prepared either by hydrolysis of the cyanhydrin of parahydroxybenzaldehyde (Beil, X, page 410), or by reduction with a sodium amalgam of parahydroxyphenylglyoxylic acid (Beil, X, 1st supple., page 199), or by condensation of glyoxylic acid with phenol (Riedel de Haen A.G., German Patent No. 621 567; Haarmann and Riemer, G.m.b.H.,
French Patent No. 2,132,364), or lastly by hydrolysis of parahydroxyphenyltrichioromethylcarbinol derived from the condensation of chloral with phenol (H. Haakh and A. Smole, Austrian Patent No. 141 159).
However, carbonyl derivatives in an alkaline aqueous medium and particularly glyoxylic acid are subject to the Canizzaro reaction; when hot, glyoxylic acid decomposes completely into oxalic and glycolic acids (Boettinger,
Ber. 13, 1931 (1980)).
It is to avoid this Cannizzaro reaction becoming preponderant and destroying the glyoxylic acid utilized that the condensation process of glyoxylic acid with phenolic rings in an alkaline aqueous medium are carried out at a temperature close to room temperature. Thus in the process described in German Patent No. 621 567, an aqueous alkaline solution of phenol and of glyoxylic acid are left for several days at ambient temperature. In French Patent No. 2,132,364, the condensation of the glyoxylic acid with an excess of phenol is carried out in 10% caustic soda solution, for 36 hours between 15 and 25°C.
More generally, the processes of preparing racemic arylglycolic acids by condensation of glyoxylic acids on a phenolic ring are carried out at a temperature below 25°C. J. Goodman et Coll., (Biochem. Biophys. Acta. 156,364-7, 1968) condense glyoxylic acid with guaiacol in 68 hours at 25°C, whereas J. Kamlet, (U.S.A. Patent No. 2,640,083), operates for 48 hours between 15 and 20°C to prepare racemic 4-hydroxy-3-methoxy mandelic acid.
- 3 49303
A. I. Fatiadi and R. Schaffer, (J. Research Nat. Bur. Sand., Sect. A, 78A, 411-12, 1972), studied the temperature factor on the condensation of glyoxylic acid on guaiacol; they concluded that any rise in temperature was detrimental to the yield and recommend carrying out this condensation by introducing the glyoxylic acid into an alkaline aqueous of guaiacol cooled to O’C over 4 hours and then leaving it for 20 hours from 0 to 20°C. For the manufacture of racemic 3,4-dihydroxy mandelic acid, the Nippon Synthetic Chemical Industry Co. Ltd. in Japanese Patent Application No. 75-29522, teaches carrying out the condensation of the glyoxylic acid with pyrocatechol over 2 hours at 5 to 8°C, then for 24 hours at 10-15°C and finally over 24 hours at ambient temperature.
According to the Irish Patent No. 47116 an alkali metal salt of p-hydroxymandelic acid can be obtained by reacting in a conventional manner, advantageously at a temperature between 20 and 60°C and preferably between 30 and 40°C, phenol with glyoxylic acid in the presence of the selected alkali metal hydroxide.
It is obvious that these methods: low-temperatures - long reaction times, result in a reduction of the productivity of the plant, an increase in investment and lend themselves with difficulty to large tonnage industrial production.
Accordingly, it is an object of the present invention to provide a method for the manufacture of racemic parahydroxymandelic acid which improves these temperatures and time reaction restrictions.
It is another object of the invention to provide such a method which improves the productivity of the installation.
It is a further object of the invention to provide such a process which lends itself more readily to large scale production.
Other objects and advantages of the invention will be apparent from the description which follows.
Applicants have now discovered surprisingly and unexpectedly that the condensation of glyoxylic acid with phenol in an alkaline aqueous medium could be carried out very easily at temperatures comprised between 30 and 100°C, whilst preserving good selectivity, providing excellent yields and considerably shortening the reaction time.
According to the invention, there is provided a process for preparing racemic parahydroxymandelic acid, which process comprises reacting glyoxylic acid with an excess of phenol in water in the presence of an alkaline agent at a temperature from 30 to 100°C, neutralizing the reaction medium, removing the unconverted phenol by extraction with a water immiscible organic solvent, acidifying the aqueous phase to a pH of 0.5 and extracting the parahydroxymandelic acid with a water immiscible solvent. The racemic parahydroxymandelic acid can be isolated with evaporation of the extraction solvent.
A suitable alkaline agent is sodium or potassium hydroxide.
In a preferred embodiment, the process comprises condensing at a temperature of from 30 to 100°C, preferably from 70 to 100°C, and more preferably from 70 to 85°C, in a nitrogen atmosphere, 1 mole of 50? glyoxylic acid in water with 2 to 3 moles of phenol in 2 liters of water containing 2 to 3 moles of sodium hydroxide for a time less than or equal to 70 minutes, then neutralizing the solution with 50? sulphuric acid in water, then extracting the unconverted phenol with 1,2-dichloro-ethane. Finally, the aqueous phase acidified to pH = 0.5 with 50? sulphuric acid in water, is extracted with ethyl acetate.
In this way there is isolated, after evaporation of the ethyl acetate, crystalline, racemic parahydroxymandelic acid, monohydrate with a yield of
70 to 85? with respect to the glyoxylic acid utilized.
Preferably the condensation is performed in 1 to 3 liters of water per mole of glyoxylic acid.
The following examples are given purely by way of illustrative and non-limiting description of the invention.
- 5 49308
EXAMPLE 1.
A solution of 296 g (2 moles of 50% glyoxylic acid in water, 564 g (6 moles) of phenol and 160 g (4 moles) of caustic soda in pellets in 3.6 liters of water are heated for 30 minutes at 82°C with stirring and under a nitrogen atmosphere. After cooling to 40°C, the reaction solution is hrought to pH:6.5 with 50% sulphuric acid in water, then after cooling to room temperature, the unconverted phenol is extracted by means of 1,2-dichloroethane; 376 g of phenol, after evaporation of the solvent, are thus isolated. The aqueous phase is then acidified to pH 0.5 with 50% sulphuric acid in water and then, after saturation with sodium chloride, it is extracted several times with ethyl acetate. In this way, after evaporation of the ethyl acetate and trying under vacuum at 40°C for 60 hours, 285 g of crystalline racemic parahydroxymandelic acid monohydrate are isolated, having a melting point in tube of 83-85°C, namely a yield of 76.5% with respect to the glyoxylic acid utilized.
EXAMPLE 2.
A solution of 296 g (2 moles) of 50% glyoxylic acid in water, 564 g (6 moles) of phenol and 160 g (4 moles) of caustic soda in pellets in 3.6 liters of water are heated for 30 minutes at 100°C with stirring and under a nitrogen atmosphere. Then procedure is as in Example 1. In this way the racemic parahydroxymandelic acid monohydrate is isolated with a yield of 72% with respect to the glyoxylic acid utilized,
EXAMPLE 3.
A solution of 296 g (2 moles) of 50% glyoxylic acid in water, 564 g (6 moles) of phenol and 200 g (5 moles) of caustic soda in pellets in 3.6 liters of water is heated for 1 hour at 50°C, with stirring and under a nitrogen atmosphere. Then procedure is as in Example 1. In this way the racemic
- 6 48308 parahydroxymandelic acid monohydrate is isolated with a yield of 78% with respect to the glyoxylic acid utilized.
EXAMPLE 4.
A solution of 296 g (2 moles) of 50% glyoxylic acid in water, 564 g (6 moles) of phenol and 180 g (4.5 moles) of caustic soda in pellets in 3.6 liters of water is heated for 30 minutes from 30 to 85°C, then cooled in 30 minutes to 40°C, with stirring and under a nitrogen atmosphere. Then procedure as is in Example 1. In this way the racemic parahydroxymandelic acid monohydrate is isolated with a yield of 81% with respect to the glyoxylic acid utilized.
EXAMPLE 5.
A solution of 296 g (2 moles) of 50% glyoxylic acid in water, 564 g (6 moles) of phenol and 160 g (4 moles) of caustic soda in pellets in 3.6 liters of water are heated for 30 minutes at 70°C, with stirring and under a nitrogen atmosphere. Procedure is then as in Example 1. In this way the racemic parahydroxymandelic acid monohydrate is isolated with a yield of 83.5% with respect to the glyoxylic acid utilized.
EXAMPLE 6.
Into a solution of 133.2 g (0.9 mole) of 50% glyoxylic acid in water and 990 g of water heated under reflux in a nitrogen atmosphere, is introduced with stirring and at once, a hot solution prepared at that moment by dissolving under reflux in a nitrogen atmosphere 253.8 g (2.7 moles) of phenol and 81 g (2.025 moles) of sodium hydroxide in pellets in 630 g of water is introduced. The resulting solution is then kept stirred and under a nitrogen atmosphere, at 100°C for 5 minutes, then the solution is neutralized while hot to a pH of 6.5 with 6N hydrochloric acid. After cooling to room temperature, procedure is as in Example 1. In this way 169 g (1.8 mole) of phenol is recovered and then the racemic parahydroxymandelic acid monohydrate
- 7 - 49308 is isolated with a yield of 67.5% with respect to the glyoxylic acid utilized.
Claims (8)
1. Process for manufacturing racemic parahydroxymandelic acid, which process comprises reacting glyoxylic acid with an excess of phenol in water in the presence of an alkaline agent at a temperature from 30 to 10Q°C, neutralizing the reaction medium, removing the unconverted phenol by extraction with a water immiscible organic solvent, acidifying the aqueous phase to a pH of 0.5, and extracting the parahydroxymandelic acid with a water immiscible solvent.
2. Process according to Claim 1, wherein the condensation is carried out at a temperature of from 70 to 100°C.
3. Process according to Claim 2, wherein the condensation is carried out at a temperature of from 70 to 85°C.
4. Process according to Claim 1, 2 or 3, wherein the alkaline agent is sodium or potassium hydroxide.
5. Process according to Claim 4, wherein the condensation is carried out in the presence of 2 to 3 moles of sodium or potassium hydroxide per mole of glyoxylic acid.
6. Process according to any preceding claim wherein the condensation is carried out in 1 to 3 liters of water per mole of glyoxylic acid.
7. Process according to any preceding claim, wherein 1 mole of glyoxylic acid is condensed with an excess of 2 to 3 moles of phenol,
8. Process according to any preceding claim, wherein the condensation is carried out in a time less than or equal to 70 minutes.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7831123A FR2440350A1 (en) | 1978-11-03 | 1978-11-03 | PROCESS FOR PRODUCING RACEMIC PARAHYDROXYMANDELIC ACID |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IE792108L IE792108L (en) | 1980-05-03 |
| IE49308B1 true IE49308B1 (en) | 1985-09-18 |
Family
ID=9214433
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IE2108/79A IE49308B1 (en) | 1978-11-03 | 1979-11-02 | Process for manufacturing racemic parahydroxymandelic acid |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5564546A (en) |
| BE (1) | BE879359A (en) |
| CA (1) | CA1125784A (en) |
| CH (1) | CH642047A5 (en) |
| DE (1) | DE2944295C2 (en) |
| FR (1) | FR2440350A1 (en) |
| GB (1) | GB2034308B (en) |
| IE (1) | IE49308B1 (en) |
| IT (1) | IT1124842B (en) |
| NL (1) | NL189910C (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2462415A1 (en) * | 1979-07-25 | 1981-02-13 | Hoechst France | PROCESS FOR PREPARING RACEMIC HYDROXYARYLGLYCOLIC ACIDS AND PRODUCTS THEREOF |
| FR2495137A1 (en) * | 1980-11-28 | 1982-06-04 | Hoechst France | Para-hydroxy-mandelic acid continuous prepn. - from glyoxylic acid, phenol and sodium hydroxide in aq. soln. in reactors arranged in series |
| TW206220B (en) * | 1991-07-01 | 1993-05-21 | Ciba Geigy Ag | |
| US5252643A (en) * | 1991-07-01 | 1993-10-12 | Ciba-Geigy Corporation | Thiomethylated benzofuran-2-ones |
| EP0545861B1 (en) * | 1991-11-29 | 1995-12-27 | Ciba-Geigy Ag | Diphenylacetic acid derivatives as stabilisers for organic material |
| NL9300801A (en) * | 1992-05-22 | 1993-12-16 | Ciba Geigy | 3- (ACYLOXYPHENYL) BENZOFURAN-2-ON AS STABILIZERS. |
| TW260686B (en) * | 1992-05-22 | 1995-10-21 | Ciba Geigy | |
| GB2267490B (en) * | 1992-05-22 | 1995-08-09 | Ciba Geigy Ag | 3-(Carboxymethoxyphenyl)benzofuran-2-one stabilisers |
| MX9305489A (en) * | 1992-09-23 | 1994-03-31 | Ciba Geigy Ag | 3- (DIHIDROBENZOFURAN-5-IL) BENZOFURAN-2-ONAS, STABILIZERS. |
| TW255902B (en) * | 1992-09-23 | 1995-09-01 | Ciba Geigy | |
| FR2705669B1 (en) * | 1993-05-28 | 1995-08-25 | Hoechst France | Process for the preparation of hydroxyphenylacetic acids. |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE617763C (en) * | 1932-03-22 | 1935-08-24 | J D Riedel E De Haeen Akt Ges | Process for the production of aromatic oxyaldehydes |
| DE621567C (en) * | 1932-06-25 | 1935-11-09 | J D Riedel E De Haeen A G | Process for the production of aromatic oxyaldehydes |
| DE2115551C3 (en) * | 1971-03-31 | 1980-01-10 | Haarmann & Reimer Gmbh, 3450 Holzminden | Process for the production of aromatic hydroxyaldehydes |
-
1978
- 1978-11-03 FR FR7831123A patent/FR2440350A1/en active Granted
-
1979
- 1979-10-11 BE BE0/197604A patent/BE879359A/en not_active IP Right Cessation
- 1979-10-18 CH CH938079A patent/CH642047A5/en not_active IP Right Cessation
- 1979-10-19 CA CA337,999A patent/CA1125784A/en not_active Expired
- 1979-10-29 JP JP13972579A patent/JPS5564546A/en active Pending
- 1979-10-29 GB GB7937472A patent/GB2034308B/en not_active Expired
- 1979-10-30 IT IT26924/79A patent/IT1124842B/en active
- 1979-11-02 IE IE2108/79A patent/IE49308B1/en not_active IP Right Cessation
- 1979-11-02 DE DE2944295A patent/DE2944295C2/en not_active Expired
- 1979-11-05 NL NLAANVRAGE7908100,A patent/NL189910C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| NL189910C (en) | 1993-09-01 |
| IT7926924A0 (en) | 1979-10-30 |
| FR2440350A1 (en) | 1980-05-30 |
| GB2034308B (en) | 1983-03-30 |
| GB2034308A (en) | 1980-06-04 |
| FR2440350B1 (en) | 1981-05-22 |
| DE2944295A1 (en) | 1980-05-08 |
| BE879359A (en) | 1980-04-11 |
| CH642047A5 (en) | 1984-03-30 |
| IE792108L (en) | 1980-05-03 |
| NL7908100A (en) | 1980-05-07 |
| DE2944295C2 (en) | 1982-02-04 |
| NL189910B (en) | 1993-04-01 |
| CA1125784A (en) | 1982-06-15 |
| JPS5564546A (en) | 1980-05-15 |
| IT1124842B (en) | 1986-05-14 |
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|---|---|---|---|
| MM4A | Patent lapsed |