http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4870209-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_ffd5c0be49eb3aa2d3bac47e6f7fe9a6 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C215-76 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C213-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C67-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C215-76 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C213-10 |
| filingDate | 1987-04-29-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| grantDate | 1989-09-26-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_2e94e8019120f08639cb0f4d3928c3ab http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_3eab0ef13c0822cd815620e7d9a3cd3f |
| publicationDate | 1989-09-26-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | US-4870209-A |
| titleOfInvention | Process for purifying crude 4-aminophenol |
| abstract | A process for the purification of crude 4-aminophenol which was prepared by the catalytic hydrogenation of nitrobenzene in aqueous sulfuric acid is described involving: adjusting the pH of an aqueous solution of crude 4-aminophenol to pH 4.0-5.0 at a temperature between 75° C. and 85° C.; mixing the aforesaid solution with toluene as the solvent, in order to extract various impurities and the dissolved nitrobenzene starting material; adjusting the pH of the resultant solution as required to maintain it at pH 4.0-5.0; allowing the resultant mixture to settle thereby forming a top organic layer and a bottom aqueous raffinate layer which raffinate contains 4-aminophenol and the by-product material, ortho-aminophenol; separating the two layers and repeatedly extracting the raffinate layer which toluene at pH 4.0-5.0 at a temperature of 75°-85° C. until most impurities have been removed from the resultant final raffinate; adding to the resultant raffinate, a charcoal decolorizing agent and a sodium sulfite type salt, which are then removed, leaving a filtrate which contains the 4-aminophenol and also the by-product ortho-aminophenol; adjusting the pH of said filtrate to pH 6.5-8.0 and cooling it to a temperature below 10° C.; separating the precipitated pure 4-aminophenol from the by-product ortho-aminophenol which remains in the solution. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6242650-B1 |
| priorityDate | 1987-04-29-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 39.