http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-405699-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_73ee0bacab5a7576a6a3244747f6ea99 http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_715e14b8ed19cc77598a89efcdc409a3 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C67-22 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C67-22 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C69-54 |
| filingDate | 1932-08-12-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1934-02-12-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-405699-A |
| titleOfInvention | Improvements in or relating to the manufacture of esters of methacrylic acid |
| abstract | Methacrylic acid esters of monohydric alcohols are manufactured by treating acetone cyanhydrin with concentrated or fuming sulphuric acid at a raised temperature ranging from below 80 DEG C. to somewhat above 100 DEG C., advantageously at 100--110 DEG C., and then heating the reaction mixture with a monohydric alcohol, e.g. ethyl, methyl, propyl, butyl, amyl or cetyl alcohol, cyclohexanol, ethylene glycol monoethyl ether, ethylene glycol monoacetate or ethylene chlorhydrin. Advantageously the mixture of acetone cyanhydrin and sulphuric acid is maintained at a temperature above 80 DEG C., preferably about 140 DEG C., for at least an hour before adding the alcohol. The acetone cyanhydrin used may be the crude product obtained by reacting hydrocyanic acid and acetone in the presence of a catalyst, the best results being obtained when the cyanhydrin has been cooled to -15 DEG C. before neutralization, using potassium carbonate or a strong organic base as catalyst. The amount of sulphuric acid, which is preferably of 94--100 per cent strength, should be at least one molecular proportion and preferably rather more, e.g. 1\ba1/4\be--1\ba1/2\be molecular proportions, to one molecular proportion of cyanhydrin. The reaction with the monohydric alcohol may be performed in a closed vessel, in a vessel with a reflux condenser or under such conditions that the ester produced is distilled off, and it is preferably carried out in the presence of anti-polymerization materials, e.g. sulphur, diphenylamine, copper, hydroquinone or cresol, which are desirably added at an early stage. The esters may be recovered by diluting the reaction mixture with water or by distillation, preferably vacuum or steam distillation, and may be purified by washing with water or dilute alkali followed by drying, e.g. over calcium chloride, and redistillation in the presence of a polymerisation inhibitor. Examples describe the preparation of methyl, ethyl and n-butyl methacrylates, in some cases together with a certain amount of the corresponding ester of a -hydroxyisobutyric acid. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/DE-749643-C http://rdf.ncbi.nlm.nih.gov/pubchem/patent/WO-0250015-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2571194-A |
| priorityDate | 1932-08-12-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 64.