US2829088A - Process of refining dimethylformamide - Google Patents
Process of refining dimethylformamide Download PDFInfo
- Publication number
- US2829088A US2829088A US389878A US38987853A US2829088A US 2829088 A US2829088 A US 2829088A US 389878 A US389878 A US 389878A US 38987853 A US38987853 A US 38987853A US 2829088 A US2829088 A US 2829088A
- Authority
- US
- United States
- Prior art keywords
- dimethylformamide
- dimethylamine
- ammonia
- under
- refining
- 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 - Lifetime
Links
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 title claims description 66
- 238000000034 method Methods 0.000 title claims description 7
- 238000007670 refining Methods 0.000 title description 3
- ROSDSFDQCJNGOL-UHFFFAOYSA-N Dimethylamine Chemical compound CNC ROSDSFDQCJNGOL-UHFFFAOYSA-N 0.000 claims description 22
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims description 20
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 8
- 229910021529 ammonia Inorganic materials 0.000 claims description 7
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 4
- 239000008096 xylene Substances 0.000 claims description 4
- 150000001491 aromatic compounds Chemical class 0.000 claims description 3
- 238000004508 fractional distillation Methods 0.000 claims description 2
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 12
- 239000000243 solution Substances 0.000 description 4
- 238000009987 spinning Methods 0.000 description 4
- 238000009835 boiling Methods 0.000 description 3
- 238000004821 distillation Methods 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000006227 byproduct Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000009183 running Effects 0.000 description 2
- 229920002994 synthetic fiber Polymers 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000002845 discoloration Methods 0.000 description 1
- 238000000578 dry spinning Methods 0.000 description 1
- 238000007380 fibre production Methods 0.000 description 1
- 238000005194 fractionation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C233/00—Carboxylic acid amides
Definitions
- This invention relates to a method of refining dimethylformamide, a substance which plays an important role in the production, by spinning, of artificial fibers.
- Example 1 To 90 parts by volume crude dimethylformamide were added 10 parts benzene and the mixture was fractionated under normal pressure and slowly heating from up to C. At first benzene, containing the amine present and traces of water, distilled over and further distillation under a vacuum yielded pure dimethylformamide which was now driven over at 60 C. under a vacuum of 28 Torr.
- Example 2 To 90 parts by volume crude dimethylformamide were added 6 parts benzene and 4 parts of a light benzine boiling between 80 and 90 C. and the mixture was subjected to fractionation. Here again the traces of dimethylamine were driven over first with traces of water, the temperature being slowly raised from 65 to 80 C. Further distillation at 60 under a vacuum of 28 Torr yielded an altogether pure dimethylformamide.
- Example 3 To parts by volume crude dimethylformamide were added 15 parts toluene and the mixture distilled at 65-69 C. under a vacuum of 200 Torr. The first runnings contain in the toluene also such quantities of water and dimethylamine, but then pure dimethylformamide distills over at a temperature of 72 C. under a vacuum of 50 Torr.
- Example 4 parts of crude dimethylformamide are mixed with 10 parts technical xylene, boiling at 136-l40 C. and the mixture fractionated at 6572 C. under a vacuum of 80 Torr.
- the first runnings again contain the impurities and a perfectly pure dimethylformamide is obtained at 72 C. under a vacuum of 50 Torr.
- the method of purifying dimethylformamide contaminated with dimethylamine and ammonia which comprises admixing to the dimethylformamide, up to 20 percent by weightof the dimethylformamide, of an aromatic compound selected from the class consisting of benzene, toluene and xylene, and subjecting the mixture thus obtained to a fractional distillation whereby to remove any dimethylamine and ammonia leaving purified dimethylformamide as a residue.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
United States Patent PROCESS or nnrrynqn nrM rnr/rranMAMrnE Ernst Pirot, Erlenbach (Main), Germany, assignor to Vereinigte Glanzstor'f-Fabriken Alrtiengesellschaft, Wuppertal-Elberfeld, Germany, a joint-stock company under German law No Drawing. Application November 2, 1953 Serial No. 389,878
Claims priority, application Germany November 8, 1952 2 Claims. (Cl. 202-56) This invention relates to a method of refining dimethylformamide, a substance which plays an important role in the production, by spinning, of artificial fibers.
It is an object of this invention to provide a simple process for purifying or refining crude dimethylformamide by freeing it from impurities which greatly impair its usefulness as a spinning solution.
As is well known to persons skilled in the art of artificial fiber production, when dry-spinning polyacrylonitriledimethylformamide solution and recovering the dimethylformamide, a product is obtained which, owing to the relatively high working temperatures which exceed 150 C., has to a certain extent be decomposed by cracking and contains by-products such as for instance dimethylamine and even ammonia. The normal Way of dealing with such crude mixture by distilling it under pressure or in a vacuum does not lead to a satisfactory separation of these by-products from the dimethylformamide. If, however, the refined product still contains traces of dimethylamine or ammonia, it will, if used again as spinning solu tion, being about a strong discoloration and gelatinisation of the material. Even as little as 0.1% dimethylamine in the solution lead to so strong a gelatinisation as to create disturbances in the spinning process. Hitherto no means were known for doing away with these traces of dimethylamine.
I have now found a very simple way of getting rid of this impurity and altogether regenerating the dimethylformamide in pure condition. I achieve this by subjecting the raw product to distillation together with up to 20% of an aromatic compound which boils at a lower temperature than the dimethylformamide and more es- .pecially benzene, toluene and xylene.
In practicing my invention, I may for instance proceed as follows:
Example 1 To 90 parts by volume crude dimethylformamide were added 10 parts benzene and the mixture was fractionated under normal pressure and slowly heating from up to C. At first benzene, containing the amine present and traces of water, distilled over and further distillation under a vacuum yielded pure dimethylformamide which was now driven over at 60 C. under a vacuum of 28 Torr.
Example 2 To 90 parts by volume crude dimethylformamide were added 6 parts benzene and 4 parts of a light benzine boiling between 80 and 90 C. and the mixture was subjected to fractionation. Here again the traces of dimethylamine were driven over first with traces of water, the temperature being slowly raised from 65 to 80 C. Further distillation at 60 under a vacuum of 28 Torr yielded an altogether pure dimethylformamide.
Example 3 To parts by volume crude dimethylformamide were added 15 parts toluene and the mixture distilled at 65-69 C. under a vacuum of 200 Torr. The first runnings contain in the toluene also such quantities of water and dimethylamine, but then pure dimethylformamide distills over at a temperature of 72 C. under a vacuum of 50 Torr.
Example 4 parts of crude dimethylformamide are mixed with 10 parts technical xylene, boiling at 136-l40 C. and the mixture fractionated at 6572 C. under a vacuum of 80 Torr. The first runnings again contain the impurities and a perfectly pure dimethylformamide is obtained at 72 C. under a vacuum of 50 Torr.
Various changes may be made in the proportions of the materials and the temperatures and pressures used without departing from the invention or sacrificing the advantages thereof.
I claim:
1. The method of purifying dimethylformamide contaminated with dimethylamine and ammonia which comprises admixing to the dimethylformamide, up to 20 percent by weightof the dimethylformamide, of an aromatic compound selected from the class consisting of benzene, toluene and xylene, and subjecting the mixture thus obtained to a fractional distillation whereby to remove any dimethylamine and ammonia leaving purified dimethylformamide as a residue.
2. The method of claim 1, wherein a small quantity of a light benzine boiling within the range of 70 to 90 C Great Britain Jan. 21, 1941 is added to the mixture prior to the fractional distilla-
Claims (1)
1. THE METHOD OF PURIFYING DIMETHYLFORMAMIDE CONTAMINATED WITH DIMETHYLAMINE AND AMMONIA WHICH COMPRISES ADMIXING TO THE DIMETHYLAMINE AND AMMONIA WHICH COMCENT BY WEIGHT OF THE DIMETHYLFORMAMIDE, OF AN AROMATIC COMPOUND SELECTED FROM THE CLASS CONSISTING OF BENZENE, TOLUENCE AND XYLENE, AND SUBJECTING THE MIXTURE THUS OBTAINED TO A FRACTIONAL DISTILLATION WHEREBY TO REMOVE ANY DIMETHYLAMINE AND AMMONIA LEAVING PURIFIED DIMETHYLFORMAMIDE AS A RESIDUE.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2829088X | 1952-11-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2829088A true US2829088A (en) | 1958-04-01 |
Family
ID=7999212
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US389878A Expired - Lifetime US2829088A (en) | 1952-11-08 | 1953-11-02 | Process of refining dimethylformamide |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2829088A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3419476A (en) * | 1967-04-11 | 1968-12-31 | Du Pont | Process for recovering liquid carboxylic acid amine solvent from aqueous solution thereof containing acetylenic polymers by flash distillation with a hydrocarbon oil |
| US4177111A (en) * | 1976-07-15 | 1979-12-04 | Bayer Aktiengesellschaft | Process for the recovery of dimethylacylamides |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2106579A (en) * | 1936-03-30 | 1938-01-25 | Du Pont | Manufacture of formamide |
| GB532258A (en) * | 1939-07-19 | 1941-01-21 | William Tyerman | Improvements in and relating to the manufacture of mono- and dimethyl formamides |
| US2388217A (en) * | 1943-02-26 | 1945-10-30 | Sharples Chemicals Inc | Separation of trimethyl amine and ammonia from amination reaction mixtures |
| US2461191A (en) * | 1947-10-21 | 1949-02-08 | Du Pont | Vacuum distillation of trimethylamine from dimethylamine |
| US2570291A (en) * | 1946-12-04 | 1951-10-09 | Ici Ltd | Extractive distillation of methylamines |
| US2602817A (en) * | 1949-06-24 | 1952-07-08 | Monsanto Chemicals | Extraction of dimethylacetamide |
| US2677706A (en) * | 1951-08-16 | 1954-05-04 | Commercial Solvents Corp | Preparation of n substituted formamides |
-
1953
- 1953-11-02 US US389878A patent/US2829088A/en not_active Expired - Lifetime
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2106579A (en) * | 1936-03-30 | 1938-01-25 | Du Pont | Manufacture of formamide |
| GB532258A (en) * | 1939-07-19 | 1941-01-21 | William Tyerman | Improvements in and relating to the manufacture of mono- and dimethyl formamides |
| US2388217A (en) * | 1943-02-26 | 1945-10-30 | Sharples Chemicals Inc | Separation of trimethyl amine and ammonia from amination reaction mixtures |
| US2570291A (en) * | 1946-12-04 | 1951-10-09 | Ici Ltd | Extractive distillation of methylamines |
| US2461191A (en) * | 1947-10-21 | 1949-02-08 | Du Pont | Vacuum distillation of trimethylamine from dimethylamine |
| US2602817A (en) * | 1949-06-24 | 1952-07-08 | Monsanto Chemicals | Extraction of dimethylacetamide |
| US2677706A (en) * | 1951-08-16 | 1954-05-04 | Commercial Solvents Corp | Preparation of n substituted formamides |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3419476A (en) * | 1967-04-11 | 1968-12-31 | Du Pont | Process for recovering liquid carboxylic acid amine solvent from aqueous solution thereof containing acetylenic polymers by flash distillation with a hydrocarbon oil |
| US4177111A (en) * | 1976-07-15 | 1979-12-04 | Bayer Aktiengesellschaft | Process for the recovery of dimethylacylamides |
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