GB667075A - An improved process for the manufacture of lactams - Google Patents
An improved process for the manufacture of lactamsInfo
- Publication number
- GB667075A GB667075A GB1771/50A GB177150A GB667075A GB 667075 A GB667075 A GB 667075A GB 1771/50 A GB1771/50 A GB 1771/50A GB 177150 A GB177150 A GB 177150A GB 667075 A GB667075 A GB 667075A
- Authority
- GB
- United Kingdom
- Prior art keywords
- lactam
- neutralization
- per cent
- mixture
- separated
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
- C07D201/16—Separation or purification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Lactams are separated from the mixture obtained by Beckmann's re-arrangement of cyclic oximes with strong sulphuric acid by continuously mixing said mixture with the required amount of a neutralizing agent and with at least the same amount of a neutral salt solution obtained in a previous neutralization process and continuously drawing off the separated lactam. The components should be intimately mixed and their residence time in the neutralization zone should be as short as possible, e.g. not exceeding 3-10 minutes. Cooling with brine is not necessary and the salt solution may be used in its precooled state after removal of lactam. The neutralizing agents are preferably those which yield readily soluble sulphates, i.e. from highly concentrated solutions. Preferably the salt solutions used are nearly or totally saturated. The preferred neutralizing agent is aqueous ammonia solution containing 13-15 per cent of ammonia and 20-25 per cent sodium or potassium hydroxide solutions are also specified. The pH of the neutralization mixture should be between 3 and 8, preferably at about 6. Lactams containing 6-11 carbon atoms are preferred, those specified being caprolactam, oenatholactam, o -aminooctylic acid lactam, o -aminononylic acid lactam, o -aminodecylic acid lactam and o -amino-undecylic acid lactam. In examples: (1) the product obtained by the reaction of cyclohexanone oxime with oleum together with 14.5 per cent aqueous ammonia solution and saturated ammonium sulphate solution obtained in a prior neutralization stage flows to a neutralization vessel whose effective volume is decreased by means of a siphon overflow and then to a separator at 75 DEG C and pH6 the sulphate solution being extracted with an organic solvent; (2) is as (1) the temperature of the components being respectively 50 DEG , 20 DEG and 30 DEG C., mixing being effected in a continuous fashion through a high-speed mixer, the product is separated at 80 DEG C. and pH7 and part of the ammonium sulphate fed back, and (3) product from the reaction of suberone oxime with oleum, 15 per cent aqueous ammonium and recycled ammonium sulphate are intimately mixed as in (2) to yield a mixture which on separation has pH 6.5 and is at 90 DEG C. oenantholactam being obtained.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL667075X | 1949-01-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB667075A true GB667075A (en) | 1952-02-27 |
Family
ID=19798784
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1771/50A Expired GB667075A (en) | 1949-01-29 | 1950-01-23 | An improved process for the manufacture of lactams |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB667075A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3117964A (en) * | 1962-01-04 | 1964-01-14 | Halcon International Inc | Process of separating lactams from concentrated sulfuric acid solutions by neutralization with ammonia |
US3127395A (en) * | 1964-03-31 | Process of separating lactams from beckmann | ||
US3186984A (en) * | 1965-06-01 | Xanhydrous a ammonia |
-
1950
- 1950-01-23 GB GB1771/50A patent/GB667075A/en not_active Expired
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3127395A (en) * | 1964-03-31 | Process of separating lactams from beckmann | ||
US3186984A (en) * | 1965-06-01 | Xanhydrous a ammonia | ||
US3117964A (en) * | 1962-01-04 | 1964-01-14 | Halcon International Inc | Process of separating lactams from concentrated sulfuric acid solutions by neutralization with ammonia |
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