http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-108440336-B
Outgoing Links
| Predicate | Object |
|---|---|
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C243-02 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C273-1863 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C273-18 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C243-02 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C275-68 |
| filingDate | 2018-03-22-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| grantDate | 2021-02-26-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 2021-02-26-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | CN-108440336-B |
| titleOfInvention | Preparation method of metronidazole |
| abstract | The invention discloses a method for preparing metronidazole, which takes N, N' -dimethylurea as a raw material and comprises the following steps: (1) slowly adding a dichloromethane solution of N, N ' -dimethyl urea into a nitric-sulfuric mixed acid for nitration reaction, pouring a reaction mixture into ice water after the addition is finished, separating an organic phase, extracting a water phase with dichloromethane, combining the organic phases, and washing with a 5% sodium carbonate aqueous solution and distilled water in sequence to obtain a dichloromethane solution of N, N ' -dimethyl-N, N ' -dinitrourea; (2) adding an inorganic acid aqueous solution into a reaction bottle, heating to boil, starting to dropwise add the dichloromethane solution of the N, N '-dimethyl-N, N' -dinitrourea obtained in the step (1) to perform hydrolysis reaction, preserving heat for 30min after dropwise adding, stopping heating, extracting the hydrolysate with dichloromethane, drying the extract with anhydrous magnesium sulfate, and concentrating to obtain the niclosamide. The invention aims to solve the problems of insufficient hydrolysis, low yield and the like of N, N '-dimethyl-N, N' -dinitrourea in the preparation process of the metronidazole. The method is mainly used for preparing the metronidazole. |
| priorityDate | 2018-03-22-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 42.