http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-862581-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_31333490fbc73df5e77aba8ae8600fbb |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07D213-67 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07D213-66 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07D213-66 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07D213-67 |
| filingDate | 1957-01-02-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_24161f2658778f516e30bd10d6407fa2 http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_9650cf34328dcdc1c5dca729e1af333d http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_ff6c1708881b950000d93e0706bc2e36 |
| publicationDate | 1961-03-15-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-862581-A |
| titleOfInvention | Improvements in or relating to the preparation of 3-pyridinols |
| abstract | 3-Pyridinols of the formula: <FORM:0862581/IV (b)/1> (wherein Z is hydrogen or CH2OH and R2 and R4 are hydrogen or alkyl) are prepared by oxidizing substituted furans of the formula: <FORM:0862581/IV (b)/2> (wherein Y is hydrogen or CH2OR1, R1 being hydrogen or aryl, and R5 is an amino group or a protected amino group) or acid-addition salts thereof by a halogen in water or by other chemical oxidizing agents in water or an aqueous or anhydrous alcohol ROH (wherein R is an alkyl, hydroxyalkyl or cycloalkyl group of not more than 6 carbon atoms) and hydrolysing to produce the required 3-pyridinol. Suitable oxidizing agents include oxyhalogenic and hypohalogenous acids and their salts, hydrogen peroxide, inorganic peroxy acids and salts thereof, organic peracids, dichromates and chromic acid, permanganates, nitric acid and nitrogen oxides. The oxidation product formed is directly hydrolysed to the 3-pyridinol, and the oxidation and hydrolysis are desirably effected at a pH of between zero and 10, the pH being adjusted if necessary by addition of an organic or mineral acid, preferably hydrochloric acid. An oxidation catalyst, such as ferrous sulphate or vanadium pentoxide, may also be added. Protection of the amino group in the starting material may be effected by conversion to the corresponding acyl, carbamate or N-mono- or N-di-carbamoyl derivative, but the amino group, and the CH2OH groups when present, are preferably free. Numerous examples describe the preparation of 3-pyridinol ,2-methyl-3-pyridinol and pyridoxine by the process of the invention using a variety of oxidizing agents, and a further example describes the oxidation of 2-(a -aminoethyl)-3:4-bis-(hydroxymethyl)-furan to 2-(a -aminoethyl)-3:4-bis-(hydroxymethyl) - 2:5- dimethoxy-and-diethoxy-2:5-dihydrofurans using aqueous sodium hypochlorite and hydrochloric acid in methanol and ethanol respectively, without a subsequent hydrolysis. The Provisional Specification refers to the use of anhydrous alcohols, aqueous alcohols, water and other solvents in general as reaction media in the oxidation process, and provides two further examples illustrating the oxidizing action of chlorine in aqueous methanol. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EP-0939079-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4192946-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6133447-A |
| priorityDate | 1957-01-02-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
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