IE48914B1 - Preparation and recovery of n-alkylethylene diamines from an alkylation mixture using a hydrocarbon solvent and fractional distillation steps - Google Patents
Preparation and recovery of n-alkylethylene diamines from an alkylation mixture using a hydrocarbon solvent and fractional distillation stepsInfo
- Publication number
- IE48914B1 IE48914B1 IE145179A IE145179A IE48914B1 IE 48914 B1 IE48914 B1 IE 48914B1 IE 145179 A IE145179 A IE 145179A IE 145179 A IE145179 A IE 145179A IE 48914 B1 IE48914 B1 IE 48914B1
- Authority
- IE
- Ireland
- Prior art keywords
- eda
- hydrocarbon solvent
- reaction mixture
- weight
- alkyl halide
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/04—Preparation of compounds containing amino groups bound to a carbon skeleton by substitution of functional groups by amino groups
- C07C209/06—Preparation of compounds containing amino groups bound to a carbon skeleton by substitution of functional groups by amino groups by substitution of halogen atoms
- C07C209/08—Preparation of compounds containing amino groups bound to a carbon skeleton by substitution of functional groups by amino groups by substitution of halogen atoms with formation of amino groups bound to acyclic carbon atoms or to carbon atoms of rings other than six-membered aromatic rings
Abstract
The invention relates to the preparation and recovery of N- alkylethylenediamines by reaction of ethylenediamine with an alkyl halide, in which the N-alkylethylenediamine is obtained substantially free of unreacted ethylenediamine by adding a hydrocarbon solvent to the alkylation reaction mixture, or to a fraction thereof containing the desired product, and then removing unreacted ethylenediamine by azeotropic distillation of the reaction mixture or fraction.
Description
The present invention relates to processes for preparing and recovering N-alkylethylenediamines which are useful as intermediates for purifying penicillins and which also are useful for preparing penicillins and cephalosporins,
In accordance with a first embodiment of the present invention there is provided a process for preparing an N-alkylethylenediamine wherein the alkyl is from Cg to Cg, comprising reacting ethylenediamine (EDA) and an (Cg-Cg) alkyl halide at a mole ratio of EDA to said alkyl halide of 1-20:1 and a temperature of from -10°C to 120°C, optionally in the presence of up to 50% by weight of water, to obtain an alkylation reaction mixture; neutralizing said reaction mixture by contacting with an aqueous solution containing 1-2 molecular equivalents, based on the alkyl halide, of an inorganic alkali selected from sodium hydroxide, potassium hydroxide and mixtures thereof; separating the inorganic halide and the aqueous layer from the neutralized organic layer and adding to said organic layer 0.02 - 100% by weight, based on the weight of said organic layer, of an aliphatic hydrocarbon solvent as hereinbefore defined; azeotropically fractionally distilling all the EDA and water from the resulting mixture; and fractionally distilling resulting reaction mixture to remove residual hydrocarbon solvent and recover said N-alkylethylenediamine, which in preferred cases at least can be obtained in a purity greater than about 99%.
As employed herein, the term aliphatic hydrocarbon solvent is defined as an aliphatic or cycloaliphatic hydrocarbon solvent which forms an azeotrope with water and/or EDA below the boiling point of the product N-alkylethylenediamine from which condensed azeotrope water and/or EDA may be separated from the hydrocarbon without inclusion of substantial amount of the N-alkylethylenediamine. Suitable hydrocarbon solvents include n-heptane, isooctane, cyclohexane, n-hexane, methylcyclohexane, and n-pentane, although the preferred aliphatic hydrocarbon solvent is n-heptane.
Preferably, the reaction between the alkyl halide and the EDA is carried out at 25°-50°C in the optional presence of up to 30½ by weight of water and at a mole ratio of EDA to alkyl halide of 2-5:1. The resulting reaction mixture is then contacted with an aqueous caustic soda and the organic layer is diluted with 0.02-20½ by weight of the hydrocarbon solvent before carrying out the distillation.
The process of the subject invention can be modified by the additional steps of: (1) recovering and recycling aqueous EDA from the azeotrope, (2) recovering and recycling the hydrocarbon solvent, and (3) contacting the separated, alkalized aqueous layer with about 10-100½ by weight of said hydrocarbon solvent based on the weight of said organic layer, separating the extracted aqueous layer and diluting the organic layer with the hydrocarbon extract before proceeding with the azeotropic fractional distillation.
The advantages of the process of the present invention over previously available processes are that (1) the final product, at least in preferred instances, has a purity greater than about 99%; and (2) the process results in high yields and high productivity.
In accordance with the present invention there is also provided a modified process for preparing an N-alkylethylenediamine wherein the alkyl is Cg-Cg comprising (a) reacting a (Cg-Cg) alkyl halide and EDA at a mole ratio of EDA to said alkyl halide of 1-20:1 and a temperature of -10°C to 120°C under anhydrous conditions to obtain an alkylation reaction mixture; (b) adding thereto 0.02-30% by weight of an aliphatic hydrocarbon solvent (as hereinbefore defined) based on the weight of said alkylation reaction mixture;
(c) fractionally distilling a mixture of EDA and said hydrocarbon solvent therefrom to essentially remove EDA from the resulting mixture;
(d) neutralizing the resulting reaction mixture by contacting it with at least 0.9 molecular equivalent, per mole of said alkyl halide, of an inorganic alkali selected from sodium hydroxide, potassium hydroxide and mixtures thereof to form a slurry of a sodium and/or potassium halide precipitate; (e) separating said alkali metal halide from said slurry and recovering the resulting mother liquor therefrom;
(f) washing said separated alkali metal halide with said hydrocarbon solvent; (g) azeotropically fractionally distilling a combination of said mother liquor from step (e) plus recovered hydrocarbon wash liquor from step (f) to remove essentially all water and residual EDA from the resulting mixture; and (h) fractionally distilling the resulting reaction mixture to remove residual hydrocarbon solvent and recover said N-alkylethylenedi ami ne.
In the preferred operation of the first-mentioned embodiment of the present process, EDA, either as an anhydrous liquid or containing water, and a (Cg-Cg) alkyl halide, preferably an alkyl chloride, are admixed in a suitable reactor vessel while agitating and maintaining the reaction mixture at from -10°C to 120°C (preferably at 25°-50°C) over a period of 5-15 hours (preferably 7-9 hours), to provide a mole ratio of EDA to alkyl halide of 1-20:1 (preferably 2-5:1) and from a reaction mixture containing 0-50% by weight of water (preferably 0-30%). Suitable alkyl halides include propyl chloride, isopropyl chloride, butyl chloride, pentyl chloride, 1-hexyl chloride, and 3-hexyl chloride.
The total residence time in the reactor vessel depends on the temperature employed, with shorter residence times employed with higher temperatures.
The reaction mixture is then vigorously contacted with an aqueous solution of the inorganic alkali to form a mixture, consisting of an organic layer, an aqueous layer, and an alkaline halide. Sufficient inorganic alkali is employed so that the pH of the aqueous layer does not go below about 7, preferably not below 8 and an aqueous layer is formed. The inorganic alkalis used herein are sodium and potassium hydroxide, either singly or in mixtures. The preferred inorganic alkali is about 50% aqueous sodium hydroxide.
The organic layer is separated from the alkali metal halide and the aqueous layer by making a phase separation, or by first separating the alkaline halide by filtration or centrifugation, and then making a phase separation. The organic layer contains the
N-alkylethylenediamine, unreacted EDA, and higher alkylation products such as Ν,Ν'-dialkylethylenediamine, Ν,Ν-dialkylethylenediamine,
Ν,Ν,N'-tri alkylethylenedi amine, and N ,N ,N' ,N1-tetraalkylethylenedi ami ne. The organic layer is then diluted with 0.02-100% by weight, preferably 0.02-20% by weight, of the aliphatic hydrocarbon solvent, based on the weight of said organic layer.
489 14
Preferably, the separated aqueous layer is extracted with 10-100% by weight, more preferably 10-20% by weight of the aliphatic hydrocarbon solvent, based on the weight of said organic layer and the two-phase mixture is allowed to settle. The extracted aqueous layer is then separated and the hydrocarbon solvent extract is used to dilute the above-mentioned organic layer.
The diluted organic layer is then heated to boiling through a distillation column to azeotropically fractionally distil off any residual EDA and water. After allowing the distillate to settle, the lower EDA-water layer may be separated and recycled to the alkylation vessel, and the upper hydrocarbon layer may be recycled to the distillation column until an anhydrous EDA-free N-alkylethylenediamine is obtained, or transferred to a vessel for extraction of the original aqueous layer.
The residual EDA-free reaction mixture, containing N-alkylethylenediamine, higher alkylated ethylenediamines, and the hydrocarbon solvent is now fractionally distilled, using a fractionation column containing sufficient theoretical plates, to separate said hydrocarbon solvent from the N-alkylethylenediamine. For example, using a column containing 15 theoretical plates and n-heptane as the solvent, the n-heptane distills off as a forerun boiling at about 98°-100°C. The forerun of hydrocarbon solvent so obtained may be recycled to other stages of the process, such as dilution of the organic layer, azeotroping EDA and water from the reaction mixture, or extracting the aqueous layer, as described above.
After removal of the forerun of hydrocarbon solvent, the distillation is continued to obtain the N-alkylethylenediamine (purity greater than 99%) in a yield of greater than 60% based on the alkyl halide charged. The procedure employed herein may also be used to remove water and/or EDA from the N-alkylethylenediamine by adding a suitable amount of said hydrocarbon solvent thereto, azeotropioally fractionally distilling the water or EDA, or both, therefrom and fractionally distilling the residue to remove excess hydrocarbon solvent and obtain anhydrous, EDA-free N-alkylethylenediamine. It is to be understood that the aforedescribed process may also be carried out continuously using appropriate vessels, such as continuous flow reactors, splitter vessels, distillation columns, and the like.
In the preferred operation of the alternative process ethylenediamine as an anhydrous liquid, is reacted with an alkyl halide as shown below
H
I
RX + H2N-CH2CH2-NH2 -R-NCH2CH2NH2 + HX wherein X is a halo atom, such as chloro, bromo, Or iodo, preferably chloro and R is C3-Cg alkyl. The reaction is carried out while agitating the reaction mixture in a suitable reactor vessel at -10°C to 120°C, preferably at 25-75°C, over a period of 1-24 hours, preferably 2-6 hours. The mole ratio of EDA to the alkyl halide employed is 1-20 to 1, preferably 2-5 to 1. The total residence time in the reactor vessel will depend on the temperature employed, with shorter residence times employed with higher temperatures.
Upon completion of the reaction, the reaction mixture is diluted with 0.02 - 30% by weight, preferably 0.5 - 1.0% by weight, of an aliphatic hydrocarbon solvent, based on the weight of the reaction mi,, cure. As employed herein the term suitable hydrocarbon solvent has the same meaning as previously defined. The diluted reaction mixture is then heated to boiling through a distillation column to azeotropically fractionally distill off any residual EDA. Optionally, the EDA distillate may be recovered and recycled.
Suitable hydrocarbon solvents include n-heptane isooctane, cyclohexane, n-hexane, methylcyclohexane, n-pentane, and the like, although the preferred hydrocarbon solvent is n-heptane.
The reaction mixture is then neutralized by contacting it with at least 0.9 molecular equivalent of an inorganic alkali per mole of alkyl halide used. As employed herein the term inorganic alkali is defined as sodium or potassium hydroxide, either singly or in mixtures. The preferred alkali agent is 50% aqueous sodium hydroxide.
The resulting alkali metal halide precipitate is separated from the resulting slurry by conventional means, such as filtration or centrifugation, and washed with the hydrocarbon solvent described previously, preferably with n-heptane.
The hydrocarbon solvent wash liquors are collected and combined with the mother liquor obtained by the separation of the alkali metal halide precipitate from the slurry . formed by the addition of the inorganic alkali to the reaction mixture. The combined liquors are azeotropically fractionally distilled at atmospheric pressure through a packed column, preferably with recycle of heptane distillate to the column, until the residual material is essentially free of EDA and water.
The resulting essentially EDA-free reaction mixture, containing the product N-alkylethylenediamine, higher alkylated ethylenediamines, and the hydrocarbon solvent is now fractionally distilled, using a fractionation column containing sufficient theoretical plates, to separate said hydrocarbon solvent from the product N-alkylethylenediamine. For example, using a column containing 15 theoretical plates, n-heytane distills off as a forerun boiling at about 98e-100eC. The forerun of hydrocarbon solvent so obtained may be recycled to other stages of the process, such as dilution of the reaction mixture, or azeotroping EDA or water from the reaction mixture.
After removal of the forerun of hydrocarbon solvent the reaction mixture is preferably clarified to remove any insolubles and distillation of the clarified solution is continued to obtain the N-alkylethylenediamine in a purity greater than 99% and a yield of greater than 60% of theoretical based on the alkyl halide charged.
It is to be understood that the aforedescribed process may also be carried out continuously using appropriate vessels, such as continuous flow reactors, separation vessels, distillation columns, and the like.
The following examples are provided to illustrate the invention. Except as otherwise noted, all parts are by weight and all ranges are inclusive of both numbers. The purity of the product is expressed as area percent, as determined by vapor phase chromatography (VPC).
Example 1 n-Propyl chloride (327.1 grams; 4.16 moles) is added to anhydrous EDA (988.9 grams; 16.48 moles) at 20°-24°C over a period of one hour. The reaction mixture is stirred for
4 hours after the addition is completed and 50% caustic soda (392 ml; 7.35 moles) and water (206 mis) are added thereto.
The resulting mixture is allowed to settle, and the aqueous salt slurry is separated and extracted twice with 280 ml of ji-heptane. The heptane extracts are added to the organic phase and the combined mixture is heated to azeotropically distil water and EDA therefrom at 88°-97°C, using a splitter device to return distilled heptane to the distillation vessel and to separate the denser aqueous EDA phase. The EDA-free residue is then fractionally distilled to obtain a heptane forerun (b.p. 97-100°C), and a main fraction of 341.3 grams of N-n-propylethylenediamine (b.p. 75-77®C at 60 mm) of greater than 99% purity by VPC. The yield is 79.5% of theoretical based on n-propyl chloride.
Calculated for C5H14N2 : C, 58.77; H, 13.81; N, 27.42 Found : C, 59.08; H, 13.87; N, 27.60
Example '2
Isopropyl chloride (327 grams; 4.16 moles) is added to anhydrous EDA (988.9 grams; 16.48 moles) at 70’C. After the addition is completed, the reaction mixture is slowly heated to 100°C, cooled to 25°C, and mixed with 50% caustic soda (391 mis; 7.35 moles) and water (206 mis). The resulting mixture is allowed to settle, and the aqueous salt slurry is separated and extracted twice with 200 mis of n-heptane. The heptane extracts are added to the organic phase and the combined mixture is heated to azeotropically distill water and EDA therefrom at 88®-97®C, using a splitter device to return distilled heptane to the distillation vessel and to separate the denser aqueous EDA phase. The EDA-free residue is then fractionally distilled to obtain a heptane forerun (b.p. 97®100*C), and a main fraction of 305 grams of N-isopropylethylenediamine (b.p. 136°-137°C) of greater than 99% purity by VPC. The yield is 71.1% of theoretical based on isopropyl chloride.
Calculated for C5H14N2 : C, 58.77; H, 13.81; N, 27.42 Found : C, 59.16; H, 13.89; N, 27.28
Example 3 n-Butyl chloride (385.4 grams; 4.16 moles) is added to anhydrous EDA (979.0 grams; 16.29 moles) at 20°-24®C over a period of one hour. The reaction mixture is stirred at 22®27®C for 4 hours after the addition is completed and 50% caustic soda (935 ml; 7.35 moles) and water (207 mis) are added thereto. The resulting mixture is allowed to settle, and the aqueous salt slurry is separated and extracted twice with 200 • 11 mis of n-heptane. The heptane extracts are added, to the organic phase and the combined mixture is heated to azeotropically distill water and EDA therefrom at 88°-97eC, using a splitter device to return distilled heptane to the distillation vessel and to separate the denser aqueous EDA phase. The EDA-free residue is then fractionally distilled to obtain a heptane fore run (b.p. 96°-100°C) and a main fraction of 348 grams of N-n-butylethylenediamine (b.p. 74°-77°C at 20-30 mm) of greater than 99% purity by VPC. The yield is 71.3% of theoretical based on n-butyl chloride.
Calculated for CgHlgN2 : C, 62.01; H, 13.88; N, 24.11
Found ; C, 61.51; H, 13.92; N, 24.13
Claims (14)
1. A process for preparing an N-alkylethylenediamine wherein the alkyl is from C 3 to C g , comprising reacting ethylenediamine (EDA) and an (C 3 -C g ) alkyl halide at a mole ratio of EDA to said alkyl halide 5 of 1-20:1 and a temperature of from -10°C to 120°C, optionally in the presence of up to 50% by weight of water, to obtain an alkylation reaction mixture; neutralizing said reaction mixture by contacting with an aqueous solution containing 1-2 molecular equivalents, based on the alkyl halide, of an inorganic alkali selected from sodium 10 hydroxide, potassium hydroxide and mixtures thereof; separating the inorganic halide and the aqueous layer from the neutralized organic layer and adding to said organic layer 0.02 - 100% by weight, based on the weight of said organic layer, of an aliphatic hydrocarbon solvent as hereinbefore defined; azeotropically fractionally distilling all the 15 EDA and water from the resulting mixture; and fractionally distilling the resulting reaction mixture to remove residual hydrocarbon solvent and recover said N-alkylethylenediamine.
2. A process according to Claim 1, wherein said EDA and alkyl halide are reacted at a mole ratio of EDA to said alkyl halide of 2-5:1 and 20 a temperature of 25°-50°C, optionally in the presence of up to 30% by weight of water, to obtain said alkylation reaction mixture; said reaction mixture is neutralized by contacting with aqueous caustic soda; and 0.02-20% by weight of said hydrocarbon is added to said organic layer. 25
3. A process according to Claim 1 or Claim 2, wherein said aliphatic hydrocarbon solvent is n-heptane.
4. A process according to any preceding claim, including the additional steps of (a) recovering aqueous EDA from the azeotrope and recycling to react with said alkyl halide; and (b) recovering the hydrocarbon solvent from the forerun of the distillation of said N-alkylethylenediamine and recycling to the distillation mixture.
5. A process according to any preceding claim, with the additional steps of contacting said aqueous layer with 10-100% by weight of said hydrocarbon solvent based on the weight of said organic layer; separating the extracted aqueous layer; and adding the hydrocarbon extract to said organic layer before proceeding with said azeotropic fractional distillation.
6. A process according to any preceding claim, wherein said alkyl halide is an alkyl chloride.
7. A process for preparing an N-alkylethylenediamine wherein the alkyl is from C 3 to Cg, comprising (a) reacting a (Cg-Cg) alkyl halide and ethylenediamine (EDA) at a mole ratio of EDA to said alkyl halide of 1-20 to 1, and at a temperature of -10°C to 120°C under anhydrous conditions to obtain an alkylation reaction mixture; (b) adding to said reaction mixture 0.02-30% by weight, based on the weight of said reaction mixture, of an aliphatic hydrocarbon solvent, as hereinbefore defined; (c) azeotropically fractionally distilling the EDA and said hydrocarbon solvent to essentially remove EDA; (d) neutralizing the resulting mixture of contacting it with at least 0.9 molecular equivalent, per mole of said alkyl halide, of an inorganic alkali selected from sodium hydroxide, potassium hydroxide and mixtures thereof, to form a slurry of an alkali metal halide precipitate; (e) separating said alkali metal halide precipitate from said slurry and recovering the resulting mother liquor; (f) washing said separated alkali metal halide with said hydrocarbon solvent; (g) azeotropically fractionally distilling a combination of said mother liquor from step (e) plus recovered hydrocarbon wash liquor from step (f) to remove essentially all water and residual EDA from the resulting mixture; and (h) fractionally distilling said 5 resulting mixture to remove residual hydrocarbon solvent and recover said N-a1ky1ethy1enediami ne.
8. A process according to Claim 7, wherein said aliphatic hydrocarbon solvent is n-heptane.
9. A process according to Claim 7 or Claim 8, wherein step (a) is at 10 a temperature of 25°C to 75°C.
10. A process according to any one of Claims 7 to 9, wherein in step (a) the mole ratio of EDA to said alkyl halide is from 2-5 to 1.
11. A process according to any one of Claims 7 to 10, wherein from 0.021.0% of said hydrocarbon, based on the weight of said reaction mixture 15 is added in step (b).
12. A process according to any one of Claims 7 to 11, wherein the inorganic alkali used in step (d) is about 50% aqueous sodium hydroxide.
13. A process according to any one of Claims 7 to 12, wherein said alkyl halide is an alkyl chloride. 20
14. A process for preparing an N-alkylethylenediamine, substantially as described in any one of the Examples herein.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/048,337 US4217308A (en) | 1978-01-30 | 1979-06-14 | Process for preparing N-alkylethylenediamines |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IE791451L IE791451L (en) | 1980-12-14 |
| IE48914B1 true IE48914B1 (en) | 1985-06-12 |
Family
ID=21954028
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IE145179A IE48914B1 (en) | 1979-06-14 | 1979-08-08 | Preparation and recovery of n-alkylethylene diamines from an alkylation mixture using a hydrocarbon solvent and fractional distillation steps |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPH0228588B2 (en) |
| BE (1) | BE877951A (en) |
| BR (1) | BR7904851A (en) |
| CA (1) | CA1128070A (en) |
| CH (1) | CH649075A5 (en) |
| DE (1) | DE2929841A1 (en) |
| FR (1) | FR2459224A1 (en) |
| GB (1) | GB2051040B (en) |
| IE (1) | IE48914B1 (en) |
| NL (1) | NL189039C (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5001267A (en) * | 1987-12-21 | 1991-03-19 | Texaco Chemical Company | Secondary alkyl amine derivatives of ethylenediamine |
| JP4532083B2 (en) * | 2003-07-28 | 2010-08-25 | 東ソー株式会社 | Method for producing N-monoalkyl-substituted alkyleneamine |
| JP4731915B2 (en) * | 2004-01-07 | 2011-07-27 | 大日本住友製薬株式会社 | Method for producing methylurea compound |
| CN103588646B (en) * | 2008-10-06 | 2016-04-13 | 陶氏环球技术有限责任公司 | Method and the methods involving of ethanolamines and ethylene amine is manufactured by oxyethane and ammonia |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1129160B (en) * | 1959-06-04 | 1962-05-10 | Basf Ag | Process for the separation of ethylene diamine and water |
| DE1130814B (en) * | 1959-12-03 | 1962-06-07 | Basf Ag | Process for the continuous dewatering of ethylene diamines |
| DE2113208C3 (en) * | 1971-03-18 | 1974-04-25 | Th. Goldschmidt Ag, 4300 Essen | Octylamine derivatives, their manufacture and use as bio silk |
| SE381867B (en) * | 1973-03-07 | 1975-12-22 | Mo Och Domsjoe Ab | WAY TO REMOVE WATER FROM A MIXTURE OF ETHYLENDIAMINE AND WATER |
| DE2455678C3 (en) * | 1974-11-25 | 1979-05-10 | Bayer Ag, 5090 Leverkusen | Process for the production of tetramethylethylenediamine |
| IL56176A (en) * | 1978-01-30 | 1982-03-31 | American Cyanamid Co | Process for preparing n-ethylethylenediamine |
-
1979
- 1979-07-23 DE DE19792929841 patent/DE2929841A1/en active Granted
- 1979-07-25 FR FR7919187A patent/FR2459224A1/en active Granted
- 1979-07-27 BR BR7904851A patent/BR7904851A/en not_active IP Right Cessation
- 1979-07-27 CH CH699179A patent/CH649075A5/en not_active IP Right Cessation
- 1979-07-27 CA CA332,700A patent/CA1128070A/en not_active Expired
- 1979-07-27 NL NL7905836A patent/NL189039C/en not_active IP Right Cessation
- 1979-07-27 GB GB7926360A patent/GB2051040B/en not_active Expired
- 1979-07-27 BE BE0/196503A patent/BE877951A/en not_active IP Right Cessation
- 1979-08-08 IE IE145179A patent/IE48914B1/en not_active IP Right Cessation
-
1980
- 1980-06-13 JP JP7916380A patent/JPH0228588B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| GB2051040B (en) | 1983-10-12 |
| BR7904851A (en) | 1981-01-27 |
| FR2459224A1 (en) | 1981-01-09 |
| IE791451L (en) | 1980-12-14 |
| NL189039C (en) | 1992-12-16 |
| GB2051040A (en) | 1981-01-14 |
| DE2929841A1 (en) | 1980-12-18 |
| NL189039B (en) | 1992-07-16 |
| FR2459224B1 (en) | 1984-06-15 |
| DE2929841C2 (en) | 1989-11-09 |
| JPH0228588B2 (en) | 1990-06-25 |
| JPS5645442A (en) | 1981-04-25 |
| NL7905836A (en) | 1980-12-16 |
| CH649075A5 (en) | 1985-04-30 |
| CA1128070A (en) | 1982-07-20 |
| BE877951A (en) | 1980-01-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3726929A (en) | Process for the production of dihalophenols | |
| US4301073A (en) | Purification of caprolactam | |
| IE48914B1 (en) | Preparation and recovery of n-alkylethylene diamines from an alkylation mixture using a hydrocarbon solvent and fractional distillation steps | |
| US4217308A (en) | Process for preparing N-alkylethylenediamines | |
| CA1158195A (en) | Process for the distillative separation of tertiary alkyl hydroperoxides and ditertiary alkyl peroxides | |
| US3886218A (en) | Process for the production of dihydroxydiphenylethers | |
| US4647689A (en) | Preparation of alkyl trifluoroacetoacetate | |
| US5393888A (en) | Non-catalytic liquid phase conversion of butyrolactone and ammonia to 2-pyrrolidone product in high yield and selectivity | |
| CA1120059A (en) | Process for preparing n-ethylethylenediamine | |
| US4792630A (en) | Process for preparing aminoacetaldehyde dialkyl acetals | |
| GB2048868A (en) | Preparation of 2',6'-dialkyl - n - alkoxymethyl - 2 - chloroacetanilides | |
| JPH06234689A (en) | Continuous industrial production of dimethoxyethanal | |
| US4986885A (en) | Process for the separation of butanol and butoxyacetaldehyde | |
| EP0749947B2 (en) | Continuous process for the manufacture of sodium C4-C8 alkoxide | |
| EP1318135B1 (en) | Method for producing 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane | |
| US2776972A (en) | Recovery of morpholine from aqueous solutions thereof | |
| US4352941A (en) | Process for purification of phenylhydrazine | |
| IE47779B1 (en) | Process for preparing n-ethylethylenediamine | |
| US5300692A (en) | Process for producing 4-amino-3-fluorobenzotrifluoride | |
| EP1019348B1 (en) | Process for the preparation of para-fluorophenol | |
| JPS6337779B2 (en) | ||
| EP0779274B1 (en) | Process for the preparation of tertiary butyl hydrazine hydrohalogenide | |
| US4992585A (en) | Process for producing α-chloroacetoacetic acid monomethylamide | |
| US5545781A (en) | Process for dehydrochlorinating 3,4-dichloro-1-butene to yield chloroprene | |
| JPH0320250A (en) | Production of n-alkylaminophenol |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MK9A | Patent expired |