http://rdf.ncbi.nlm.nih.gov/pubchem/patent/DD-296073-A5
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_c986d997e1f61f2bc6f4b7f09e16da63 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/A61K31-415 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07D231-32 |
| filingDate | 1989-10-04-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_173053d809ea5b564ef1cad9ff0ff34a http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_41ceea3ba082d2f352b704b538916532 |
| publicationDate | 1991-11-21-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | DD-296073-A5 |
| titleOfInvention | PROCESS FOR PREPARING NEW 1-SUBSTITUTED 3-HYDROXY-DELTA HIGH 2-PYRAZOLIN-5-ONES AND THEIR DERIVATIVES AND THEIR SALTS |
| abstract | The invention relates to a novel, technically simple process for the preparation of new, previously unknown 1-substituted 3-hydroxy-D2-pyrazolin-5-ones, their also new 4-bromo and 4-hydroxy derivatives and their salts with suitable bases. The 1-substituted 4-bromo-3-hydroxy-D2-pyrazolin-5-ones are obtained in high yield by brominating 1-substituted 3-hydroxy-pyrazoles in a non-oxidizing acid, most conveniently in hydrochloric acid at 5 to 30C. According to the invention, the addition of alkali bromide is required, with catalytic amounts already being sufficient. The bromination and oxidation of 3-hydroxy-pyrazoles in a acidic medium with bromide catalysis is in principle new. Furthermore, according to the invention, the 4-bromo substituent can be replaced in a technically very simple manner by means of sulfite or dithionite in aqueous alkaline or by means of zinc in alcoholic solution by hydrogen and the hydrogen by means of atmospheric oxygen in aqueous alkaline solution by OH. The replacement of bromine by OH by means of sulfite reduction and subsequent direct air oxidation is also fundamentally new and not otherwise feasible. The title compounds are of interest as antiphlogistics, antiallergic drugs, and hemostasis-affecting drugs. {3-Hydroxy-D2-pyrazolin-5-one; 1-substituted 3-hydroxy-D 2 -pyrazolin-5-one; 4-bromo-3-hydroxy-D2-pyrazolin-5-one; Bromination of 3-hydroxy-pyrazole; combined sulphite reduction / oxidation; anti-inflammatory drug; antiallergic; hemostasis} |
| priorityDate | 1989-10-04-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 76.