http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-661250-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_af99df08b153738cd418446a75d09bfc |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C17-357 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C17-00 |
| filingDate | 1949-08-10-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1951-11-21-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-661250-A |
| titleOfInvention | Manufacture of nuclear halogenated alkenyl-benzene compounds |
| abstract | Nuclear halogenated alkenylbenzenes are made by passing a vapour mixture of steam and an alkylhalobenzene having 2 or 3 carbon atoms in an alkyl radicle thereof, over a dehydrogenation catalyst at 500-750 DEG C. to form a vapour mixture of an ar-halo-alkenylbenzene compound, steam and a minor amount of a hydrogen halide, injecting into the vapour mixture flowing from the catalyst a vaporizable basic nitrogen compound of basicity at least as great as that of ammonia in amount at least as great as the chemical equivalent of the hydrogen halide present in the reaction vapours, and cooling the resultant vapour mixture, while in contact with surfaces of a ferrous metal, to condense the ar-halo-alkenyl-benzene. The nitrogen compound is preferably added as a vapour and those specified are ammonia and dimethyl-, ethyl- or diethyl-amine, preferred being gaseous ammonia and ammonium hydroxide. Usually 1-3 mols. of nitrogen compound per mol, of hydrogen halide are used. Specified alkyl halobenzenes are ethyl-chloro-, diethyl-chloro-, isopropylchloro-, isopropyldichloro-, di-isopropylchloro-, ethylbromo- and propylbromo-benzene. Usually 1-4 parts of steam per part of substituted benzene is used. Activated alumina, particularly when precarbonized with a hydrocarbon vapour at 600-700 DEG C., is the preferred catalyst, others specified being activated charcoal, kaolin, ordinary aluminium oxide and thorium oxide. Reaction is preferably effected at 550-700 DEG C. The alkenyl-halobenzene is preferably isolated by fractional distillation under vacuum in the presence of a polymerization inhibitor. Bromo-, alpha - methyl - chloro -, alpha - methyl - 3,4-dichloro- and dichloro-styrene are obtainable from ethyl-bromo-, isopropyl-chloro-, 1-isopropyl - 3,4 - dichloro and ethyl - dichlorobenzene respectively. In examples (2) and (3) chlorostyrene is prepared from ethyl-chlorobenzene gaseous ammonia being the added nitrogen compound and activated alumina, the catalyst and results obtained are compared with (1) in which no nitrogen compound is added. |
| priorityDate | 1949-08-10-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 47.