http://rdf.ncbi.nlm.nih.gov/pubchem/patent/PL-156680-B1
Outgoing Links
| Predicate | Object |
|---|---|
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C309-50 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C- |
| filingDate | 1987-04-24-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1992-04-30-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | PL-156680-B1 |
| titleOfInvention | Method of obtaining 1-amino-2-hydroxy-4-naphtalenesulfonic acid |
| abstract | This invention relates to method of producing 1-amino-2-hydroxy-4-naphthalenesulfonic acid. This compound is used to obtain 1,2-diazoxy-4-naphtalenesulfonic acid and its derivatives, which are used for synthesis of metalocomplex type 1:1 and 2:1 symmetric and asymmetric dyes from acidic and reactive group.1-amino-2-hydroxy-4- naphthalenesulfonic acid is obtained by nitrosating 2-naphthol with nitrous acid, bisulfiting 1-nitroso-2-naphthol with acidic sodium sulphite, separation of insoluble impurities, reduction and rearrangement of addition product into 1-amino-2-hydroxy-4-naphthalenesulfonic acid.One of the important stages of synthesis of the 1-amino-2-hydroxy-4- naphthalenesulfonic acid is the operation involving separation of insoluble impurities, which include unidentifiable organic compounds and ferric hydroxide, being the product of bisulfiting 1-nitroso-2-naphthol.Structure of impurities, particularly ferric hydroxide, clearly complicates separation of the impurities by filtration using straight-side presses, and leads to substantial waste.There is a method available of separation water insoluble impurities using filtration with added activated carbon. This method's fault is considerable amount of activated carbon used during the process, creating large volume of environmentally harmful waste; in addition a poor form of the sediment leading to creation of high pressure within the filtering equipment, thus causing wastage of material containing product of addition.There is also a method known, which bypasses filtration process at the synthesis of 1-amino-2-hydroxy-4-naphthalenesulfonic acid stage, in order to avoid difficulties associated with the separation of insoluble impurities; purification takes place at the final product stage,... |
| priorityDate | 1987-04-24-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 33.