http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-763520-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_04650c4315071ee8af7d26e3441a53b1 |
| filingDate | 1954-07-23-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1956-12-12-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-763520-A |
| titleOfInvention | Production of substituted pyridines |
| abstract | A reaction product comprising a vinylpyridine is prepared by catalytic reaction between formaldehyde and a methyl-substituted pyridine, the latter being heated to at least 150 DEG C. and the formaldehyde then being introduced so that it reacts at at least 150 DEG C. and under super-atmospheric pressure, the reaction product being thereafter rapidly cooled. The term " a methyl-substituted pyridine " includes pyridines containing additional substituents such as 2-methyl-5-ethyl pyridine and methyl benzo-pyridines, i.e. methyl quinolines. The reaction is particularly applicable to pyridines having a methyl-substituent in the 2-, 4- or 6-position. Suitable catalysts are, for example, a persulphate, a peroxide such as benzoyl peroxide, or a strong acid such as sulphuric or phosphoric acid, a preferred catalyst being ammonium persulphate used in an amount equal to 0.05 to 2 mol. per cent based on the formaldehyde. The formaldehyde may be supplied as a gas under pressure, as paraformaldehyde or as a formaldehyde solution, a 35-40 per cent by weight aqueous solution being preferred and the amount used being preferably 1 mol. per mol. of methyl pyridine. Advantageously, added solvents are absent but solvents such as pyridine, quinoline alcohols or water may be added. Optimum results are obtained at 240-260 DEG C. It is necessary to use relatively high pressures, e.g. 400-1500 p.s.i., and the formaldehyde is advantageously added within at most about 60 minutes, and preferably within 10-15 minutes. A polymerization inhibitor, e.g. hydroquinone, t.-butylcatechol or trinitrobenzene, may be added. The reaction products are preferably cooled to below 100 DEG C. within 5 minutes of completion of the formaldehyde addition. In an example, 3.8 mols. of 2-methyl - 5 - ethyl - pyridine, 0.014 mol. of ammonium persulphate and 0.009 mol. of hydroquinone are heated under pressure to 250 DEG C. and 3.85 mols. of 35.4 per cent formalin are added over 12.5 minutes, the pressure rising to 1050 p.s.i. After the formalin addition the mixture is cooled to below 100 DEG C. The resultant mixture contains 2-hydroxyethyl-5-ethyl pyridine, 2-vinyl-5-ethyl pyridine and unreacted methylethylpyridine. |
| priorityDate | 1953-07-24-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 41.