USRE28242E - Method for manufacturing tetronic acid - Google Patents
Method for manufacturing tetronic acid Download PDFInfo
- Publication number
- USRE28242E USRE28242E US44102874A USRE28242E US RE28242 E USRE28242 E US RE28242E US 44102874 A US44102874 A US 44102874A US RE28242 E USRE28242 E US RE28242E
- Authority
- US
- United States
- Prior art keywords
- acid
- lactone
- tetronic
- tetronic acid
- reaction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- PEQJBOMPGWYIRO-UHFFFAOYSA-N n-ethyl-3,4-dimethoxyaniline Chemical compound CCNC1=CC=C(OC)C(OC)=C1 PEQJBOMPGWYIRO-UHFFFAOYSA-N 0.000 title claims abstract description 26
- PGRHXDWITVMQBC-UHFFFAOYSA-N dehydroacetic acid Natural products CC(=O)C1C(=O)OC(C)=CC1=O PGRHXDWITVMQBC-UHFFFAOYSA-N 0.000 title claims abstract description 25
- 238000000034 method Methods 0.000 title claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 title 1
- 238000006243 chemical reaction Methods 0.000 claims abstract description 19
- 150000002596 lactones Chemical class 0.000 claims abstract description 13
- 150000004945 aromatic hydrocarbons Chemical class 0.000 claims abstract description 12
- -1 CROTONIC ACID LACTONE Chemical class 0.000 claims abstract description 11
- 239000002253 acid Substances 0.000 claims abstract description 10
- 150000004982 aromatic amines Chemical class 0.000 claims abstract description 9
- 150000008044 alkali metal hydroxides Chemical class 0.000 claims abstract description 7
- 150000003839 salts Chemical class 0.000 claims abstract description 7
- LDHQCZJRKDOVOX-UHFFFAOYSA-N trans-crotonic acid Natural products CC=CC(O)=O LDHQCZJRKDOVOX-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910052500 inorganic mineral Inorganic materials 0.000 claims abstract description 5
- 239000011707 mineral Substances 0.000 claims abstract description 5
- KUDPGZONDFORKU-UHFFFAOYSA-N n-chloroaniline Chemical compound ClNC1=CC=CC=C1 KUDPGZONDFORKU-UHFFFAOYSA-N 0.000 claims abstract description 5
- 150000004992 toluidines Chemical class 0.000 claims abstract description 5
- 229910052783 alkali metal Inorganic materials 0.000 claims abstract description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 15
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 description 11
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 150000002148 esters Chemical class 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- 125000005907 alkyl ester group Chemical group 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 229960000583 acetic acid Drugs 0.000 description 3
- 230000003197 catalytic effect Effects 0.000 description 3
- 239000012362 glacial acetic acid Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 239000012442 inert solvent Substances 0.000 description 2
- KWYUFKZDYYNOTN-UHFFFAOYSA-M potassium hydroxide Inorganic materials [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 2
- 238000000859 sublimation Methods 0.000 description 2
- 230000008022 sublimation Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 229920002359 Tetronic® Polymers 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001347 alkyl bromides Chemical class 0.000 description 1
- 150000001448 anilines Chemical class 0.000 description 1
- 125000002490 anilino group Chemical group [H]N(*)C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- HRYZWHHZPQKTII-UHFFFAOYSA-N chloroethane Chemical compound CCCl HRYZWHHZPQKTII-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000000921 elemental analysis Methods 0.000 description 1
- XYIBRDXRRQCHLP-UHFFFAOYSA-N ethyl acetoacetate Chemical compound CCOC(=O)CC(C)=O XYIBRDXRRQCHLP-UHFFFAOYSA-N 0.000 description 1
- 229960003750 ethyl chloride Drugs 0.000 description 1
- 125000004494 ethyl ester group Chemical group 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000002061 vacuum sublimation Methods 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
- 150000003738 xylenes Chemical class 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/34—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
- C07D307/56—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D307/60—Two oxygen atoms, e.g. succinic anhydride
Definitions
- ABSTRACT OF THE DISCLOSURE Process for the preparation of tetronic acid in an alkyl ester of gamma-chloro-acetoacetic acid is reacted with an aryl amine to form a beta-arylamnio crotonic acid lactone. This is reacted with an alkali metal hydroxide to form a salt of tetronic acid from which tetronic acid is obtained by acidification.
- Tetronic acid is a known compound which is utilized, amongst other purposes, as an accelerating agent for photographic development. It has been prepared by catalytic hydration of alpha-bromtetronic acid which, in turn, is prepared from alpha, gamma dibromoacetoacetic esters by heating in vacuum. In this latter reaction an alkyl bromide splits out from the dibromo compound. The process, however, is not satisfactory since it starts from the dibromo compound which has to be prepared from the acetoacetic ester (US. Pat. 3,305,363).
- tetronic acid is prepared by a series of steps in which:
- an alkyl ester of gamma-chloroacetoacetic acid is reacted with an aromatic amine in a reaction inert aromatic hydrocarbon preferably at a temperature of from about 70 C. to 140 C. to form the corresponding beta-arylamino crotonic acid lactone,
- the desired product is most conveniently isolated by vacuum sublimation at pressures up to about 0.5 torr at a temperature of from about 95 C. to 100 C.
- the initial reaction preferably takes place in the presence of catalytic quantities of a lower alkanoic acid such as glacial acetic acid. From about 1% to 2% by weight of acid based on the weight of reaction inert solvent have been found to be efiective.
- Suitable reaction inert solvents include aromatic hydrocarbons such as benzene, toluene, and the xylenes boiling from about 70 C. to 140 C. at atmospheric pressure. Benzene is preferred because of its low boiling point.
- esters of gamma-chloro-acetoacetic acid can be employed in the initial reaction.
- Esters of lower alkanols such as methanol, ethanol and propanol are preferred because of their ready availability.
- Substituted and unsubstituted aromatic amines especially aryl amines including phenyl amines such as aniline, chloranilines and toluidines can be used to prepare the novel intermediate lactones.
- Aniline is preferred because of its ready availability.
- the lactone separates from the reaction inert aromatic hydrocarbon and is reacted with an alkali metal hydroxide, suitably an aqueous hydroxide prepared from potassium or sodium hydroxide.
- the amine which separates during the reaction may be recycled for the preparation of additional quantities of tetronic acid.
- a total of 17.5 g. of the recovered product was dissolved in 150 ml. of alcohol, the solution mixed with ml. of 20% aqueous sodium hydroxide and stirred for 12 hours at 35 C. to 40 C.
- the clear solution containing the sodium salt of tetronic acid was acidified with ml. of 18% hydrochloric acid and the solvent removed by evaporation to leave a dry residue.
- the residue was sublimated at a pressure of 0.5 torr at a bath temperature of 95 C. to 100 C. to provide 6 g. of pure tetronic acid (60% of theoretical yield based on starting lactone).
- the product was identified by elemental analysis, infra-red spectra and its solidification point of C. to 141 C.
- a process for the preparation of tetronic acid which comprises the steps of:
- a process for the preparation of tetronic acid which comprises the steps of:
- DONALD G. DAUS Primary Examiner A. M. T. TIGHE, Assistant Examiner
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
1. A PROCESS FOR THE PREOAPARATION OF TETRONIC ACID WHICH COMPRISES THE STEPS OF: (A) REACTING A LOWER ALKYL ESTER OF GAMMA-CHLOROACETOACETIC ACID WITH AN ARYL AMINE, SELECTED FROM THE GROUP CONSISTING OF ANILINE, CHLOROANILINE AND TOLUIDINE IN A REACTION INERT AROMATIC HYDROCARBON AT A TEMPERATURE OF FROM ABOUT 70* C. TO 140* C. TO FORM THE CORRESPONDING BETA-ARYLAMINO CROTONIC ACID LACTONE, (B) SEPARATING SAID LACTONE FROM SAID AROMATIC HYDROCARBON, (C) REACTING SAID LACTONE WITH AN ALKALI METAL HYDROXIDE TO FORM THE ALKALI METAL SALT OF TETRONIC ACID AND (D) CONVERTING SAID SALT TO TETRONIC ACID BY REACTION WITH MINERAL ACID.
Description
United States Patent 28,242 METHOD FOR MANIXFACTURING TETRONIC CID Karl-Josef Boosen, La Neuveville, Switzerland, assignor to Lonza Ltd., Gampel, Valais, Switzerland No Drawing. Original No. 3,758,515, dated Sept. 11, 197 3,
Ser. No. 40,699, May 26, 1970. Application for reissue Feb. 7, 1974, Ser. No. 441,028 Claims priority, application Switzerland, May 28, 1969, 8,076/ 69 Int. Cl. C0711 /06 US. Cl. 260-343.6 8 Claims Matter enclosed in heavy brackets [II appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.
ABSTRACT OF THE DISCLOSURE Process for the preparation of tetronic acid in an alkyl ester of gamma-chloro-acetoacetic acid is reacted with an aryl amine to form a beta-arylamnio crotonic acid lactone. This is reacted with an alkali metal hydroxide to form a salt of tetronic acid from which tetronic acid is obtained by acidification.
BACKGROUND OF INVENTION Tetronic acid is a known compound which is utilized, amongst other purposes, as an accelerating agent for photographic development. It has been prepared by catalytic hydration of alpha-bromtetronic acid which, in turn, is prepared from alpha, gamma dibromoacetoacetic esters by heating in vacuum. In this latter reaction an alkyl bromide splits out from the dibromo compound. The process, however, is not satisfactory since it starts from the dibromo compound which has to be prepared from the acetoacetic ester (US. Pat. 3,305,363).
It is also known according to Russian Pat. 164,298 to mauufature tetronic acid by reaction of a gamma-bromoacetoacetic ester with alkali. In this method the product isolated in all cases is a derivative of tetronic acid. Moreover, the yied in the most favorable case is only about 40%.
A process has now been discovered for the preparation of tetronic acid in high yield.
The invention In accordance with this invention tetronic acid is prepared by a series of steps in which:
(1) an alkyl ester of gamma-chloroacetoacetic acid is reacted with an aromatic amine in a reaction inert aromatic hydrocarbon preferably at a temperature of from about 70 C. to 140 C. to form the corresponding beta-arylamino crotonic acid lactone,
(2) separating said lactone,
(3) reacting said lactone with an alkali metal hydroxide to form the alkai metal salt of tetronic acid, and
(4) converting said salt to tetronic acid by reaction with a mineral acid such as hydrochloric, sulfuric, and the like.
The desired product is most conveniently isolated by vacuum sublimation at pressures up to about 0.5 torr at a temperature of from about 95 C. to 100 C.
The initial reaction preferably takes place in the presence of catalytic quantities of a lower alkanoic acid such as glacial acetic acid. From about 1% to 2% by weight of acid based on the weight of reaction inert solvent have been found to be efiective.
Suitable reaction inert solvents include aromatic hydrocarbons such as benzene, toluene, and the xylenes boiling from about 70 C. to 140 C. at atmospheric pressure. Benzene is preferred because of its low boiling point.
A wide variety of esters of gamma-chloro-acetoacetic acid can be employed in the initial reaction. Esters of lower alkanols such as methanol, ethanol and propanol are preferred because of their ready availability.
Substituted and unsubstituted aromatic amines, especially aryl amines including phenyl amines such as aniline, chloranilines and toluidines can be used to prepare the novel intermediate lactones. Aniline is preferred because of its ready availability. The lactone separates from the reaction inert aromatic hydrocarbon and is reacted with an alkali metal hydroxide, suitably an aqueous hydroxide prepared from potassium or sodium hydroxide. The amine which separates during the reaction may be recycled for the preparation of additional quantities of tetronic acid.
The following non-limiting example is given by way of illustration only.
Example A total of 164.5 g. of the ethyl ester of gamma-chloroacetoacetic acid, 93 g. of aniline, 180 ml. of benzene and 3 ml. of glacial acetic acid are refluxed for 3 hours in a one liter four necked flask equipped with a stirrer, reflux condenser, thermometer and water trap. During this period 18 ml. of water and 64 g. of ethyl chloride were split off. After cooling, 152 g. of beta-amino-crotonicacid lactone crystallized from solution (87% of theoretical yield). It was recovered, washed with benzene and dried.
A total of 17.5 g. of the recovered product was dissolved in 150 ml. of alcohol, the solution mixed with ml. of 20% aqueous sodium hydroxide and stirred for 12 hours at 35 C. to 40 C. The clear solution containing the sodium salt of tetronic acid was acidified with ml. of 18% hydrochloric acid and the solvent removed by evaporation to leave a dry residue. The residue was sublimated at a pressure of 0.5 torr at a bath temperature of 95 C. to 100 C. to provide 6 g. of pure tetronic acid (60% of theoretical yield based on starting lactone).
The product was identified by elemental analysis, infra-red spectra and its solidification point of C. to 141 C.
What is claimed is:
1. A process for the preparation of tetronic acid which comprises the steps of:
(a) reacting a lower alkyl ester of gamma-chloroacetoacetic acid with an aryl amine, selected from the group consisting of aniline, chloroaniline and toluidine in a reaction inert aromatic hydrocarbon at a temperature of from about 70 C. to 140 C. to form the corresponding beta-arylamino crotonic acid lactone,
(b) separating said lactone from said aromatic hydrocarbon,
(c) reacting said lactone with an alkali metal hydroxide to form the alkali metal salt of tetronic acid and (d) converting said salt to tetronic acid by reaction with mineral acid.
2. A process as in claim 1 wherein the acid is isolated by sublimation in vacuum at a pressure up to about 0.5 torr and a temperature of from about 95 C. to 100 C.
3. A process as in claim 1 in which the reaction between the ester of gamma-chloro-acetoacetic ester and the aromatic amine is effected in the presence of catalytic quantities of glacial acetic acid.
4. A process as in claim 1 wherein the aromatic hydrocarbon is benzene.
5. A process as in claim 1 wherein the amine is aniline.
6. Beta-anilino-crotonic acid lactone.
7. A process for the preparation of tetronic acid which comprises the steps of:
(a) reacting an alkyl ester of gamma-chloro-acetoacetic acid with an aryl amine selected from the group consisting of aniline, chloroaniline and toluidine in a reaction inert aromatic hydrocarbon to form the corresponding beta-arylamino crotonic acid lactone,
(b) separating said lactone from said aromatic hydrocarbon,
(c) reacting said lactone with an alkali metal hydroxide to form the alkali metal salt of tetronic acid and (d) converting said salt to tetronic acid by reaction with mineral acid.
8. A process as in claim 7 wherein the acid is isolated by sublimation in vacuum at a pressure up to about 0.5 torr and a temperature of from about 95 C. to 100 C.
References Cited 2,605,268 7/1952 Schuster 260343.6
DONALD G. DAUS, Primary Examiner A. M. T. TIGHE, Assistant Examiner
Claims (1)
1. A PROCESS FOR THE PREOAPARATION OF TETRONIC ACID WHICH COMPRISES THE STEPS OF: (A) REACTING A LOWER ALKYL ESTER OF GAMMA-CHLOROACETOACETIC ACID WITH AN ARYL AMINE, SELECTED FROM THE GROUP CONSISTING OF ANILINE, CHLOROANILINE AND TOLUIDINE IN A REACTION INERT AROMATIC HYDROCARBON AT A TEMPERATURE OF FROM ABOUT 70* C. TO 140* C. TO FORM THE CORRESPONDING BETA-ARYLAMINO CROTONIC ACID LACTONE, (B) SEPARATING SAID LACTONE FROM SAID AROMATIC HYDROCARBON, (C) REACTING SAID LACTONE WITH AN ALKALI METAL HYDROXIDE TO FORM THE ALKALI METAL SALT OF TETRONIC ACID AND (D) CONVERTING SAID SALT TO TETRONIC ACID BY REACTION WITH MINERAL ACID.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH807669A CH503722A (en) | 1969-05-28 | 1969-05-28 | Process for the production of tetronic acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| USRE28242E true USRE28242E (en) | 1974-11-12 |
Family
ID=4334771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US44102874 Expired USRE28242E (en) | 1969-05-28 | 1974-02-07 | Method for manufacturing tetronic acid |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | USRE28242E (en) |
| CH (1) | CH503722A (en) |
| DE (1) | DE2025570C3 (en) |
| FR (1) | FR2048922A5 (en) |
| GB (1) | GB1256847A (en) |
| NL (1) | NL7007741A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4310463A (en) | 1979-02-22 | 1982-01-12 | Chevron Research | 3-(N-Arylamino)-gamma-butyrolactones, butyrolactams and thiobutyrolactones are intermediates for compounds having fungicidal activity |
| US4414400A (en) | 1981-06-17 | 1983-11-08 | Lonza Ltd. | Process for the production of tetronic acid |
| US20110152534A1 (en) * | 2009-12-23 | 2011-06-23 | Bayer Cropscience Ag | Novel process for the preparation of 4-aminobut-2-enolides starting from 4-alkoxyfuran-2(5h)-one or 4-arylalkoxyfuran-2(5h)-one |
| US8680286B2 (en) | 2009-03-16 | 2014-03-25 | Bayer Cropscience Ag | Method for producing enaminocarbonyl compounds |
| US8680285B2 (en) | 2009-03-16 | 2014-03-25 | Bayer Cropscience Ag | Method for producing enaminocarbonyl compounds |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE124396T1 (en) * | 1988-09-06 | 1995-07-15 | Lonza Ag | METHOD FOR PRODUCING 5-ALKYLTETRAMIC ACIDS. |
| JP2844868B2 (en) * | 1989-07-20 | 1999-01-13 | ロンザ リミテッド | Method for producing alkyl tetronate |
| EP2042496A1 (en) | 2007-09-18 | 2009-04-01 | Bayer CropScience AG | Method for manufacturing 4-aminobut-2-enolids |
| EP2039678A1 (en) | 2007-09-18 | 2009-03-25 | Bayer CropScience AG | Method for manufacturing 4-aminobut-2-enolids |
| TW201111370A (en) | 2009-08-18 | 2011-04-01 | Bayer Cropscience Ag | Novel process for the preparation of 4-aminobut-2-enolides |
-
1969
- 1969-05-28 CH CH807669A patent/CH503722A/en not_active IP Right Cessation
-
1970
- 1970-05-26 DE DE2025570A patent/DE2025570C3/en not_active Expired
- 1970-05-27 GB GB1256847D patent/GB1256847A/en not_active Expired
- 1970-05-28 NL NL7007741A patent/NL7007741A/xx not_active Application Discontinuation
- 1970-05-28 FR FR7019529A patent/FR2048922A5/fr not_active Expired
-
1974
- 1974-02-07 US US44102874 patent/USRE28242E/en not_active Expired
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4310463A (en) | 1979-02-22 | 1982-01-12 | Chevron Research | 3-(N-Arylamino)-gamma-butyrolactones, butyrolactams and thiobutyrolactones are intermediates for compounds having fungicidal activity |
| US4414400A (en) | 1981-06-17 | 1983-11-08 | Lonza Ltd. | Process for the production of tetronic acid |
| US8680286B2 (en) | 2009-03-16 | 2014-03-25 | Bayer Cropscience Ag | Method for producing enaminocarbonyl compounds |
| US8680285B2 (en) | 2009-03-16 | 2014-03-25 | Bayer Cropscience Ag | Method for producing enaminocarbonyl compounds |
| US20110152534A1 (en) * | 2009-12-23 | 2011-06-23 | Bayer Cropscience Ag | Novel process for the preparation of 4-aminobut-2-enolides starting from 4-alkoxyfuran-2(5h)-one or 4-arylalkoxyfuran-2(5h)-one |
| US8344151B2 (en) | 2009-12-23 | 2013-01-01 | Bayer Cropscience Ag | Process for the preparation of 4-aminobut-2-enolides starting from 4-alkoxyfuran-2(5H)-one or 4-arylalkoxyfuran-2(5H)-one |
Also Published As
| Publication number | Publication date |
|---|---|
| CH503722A (en) | 1971-02-28 |
| DE2025570A1 (en) | 1970-12-03 |
| DE2025570B2 (en) | 1979-07-05 |
| GB1256847A (en) | 1971-12-15 |
| DE2025570C3 (en) | 1980-03-06 |
| FR2048922A5 (en) | 1971-03-19 |
| NL7007741A (en) | 1970-12-01 |
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