http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-936371-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_1e70c0aeade92d7571d955d3b90ea06e |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07D201-16 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07D223-10 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07D201-04 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C249-04 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C251-44 |
| filingDate | 1961-11-16-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1963-09-11-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-936371-A |
| titleOfInvention | Improvements relating to the preparation of cyclohexanone oxime and other oximes |
| abstract | Oximes are purified by adding to a nonacidic mass containing the oxime and as a minor ingredient one or more amines, at a temperature of 25 DEG -100 DEG C., enough of a mineral acid to bring the pH of the mass to between 4 and 7, allowing the acidified mass to stratify into an aqueous phase and an organic phase, separating the two phases, and recovering purified oxime from the organic phase. In the stratification step, it is desirable to include a water-immiscible organic liquid, such as an aromatic or aliphatic hydrocarbon or halogen-substituted hydrocarbon or a mixture thereof. The process may be applied to cyclohexanone oxime, especially to compositions containing also 5-30 weight per cent of cyclohexylamine with or without some N-cyclohexylhydroxylamine, such as are obtained by catalytic hydrogenation of nitrocyclohexane in the presence of a hydrogenation catalyst and lead, as described in Specification 860,340. Sulphuric acid is the preferred mineral acid, but hydrochloric may be used. The stratification may take place in the range 25 DEG to 100 DEG C. The aqueous phase is preferably extracted to recover residual organic material. The oxime is recovered from the organic phase by distillation, or by extraction and crystallisation. Where the aqueous phase contains cyclohexylamine, this can be recovered by treating the aqueous phase with at least a stoichiometric amount of a strong base, e.g. sodium hydroxide, and then distilling a water-cyclohexylamine azeotrope from the neutralised mass. This is distilled with a water-azeotroping inert solvent to obtain a residue of anhydrous cyclohexylamine. Alternatively, cyclohexylamine is recovered from the neutralised mass by extraction with, for example, heptane, benzene or toluene, the p solvent is stripped off and the cyclohexylamine distilled. Other oximes mentioned are acetoxime and cyclopentanone oxime. |
| priorityDate | 1959-11-16-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 35.