http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-485971-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_6b6fc801b5bfe5304ffa40d938db6e09 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C309-00 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C309-43 |
| filingDate | 1937-09-10-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1938-05-27-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-485971-A |
| titleOfInvention | Improvements relating to the manufacture of sulphonic acids of the napthalene series |
| abstract | 2-Hydroxynaphthalene sulphonic acids are formed by heating until no more nitrogen is evolved, an aqueous solution or suspension of the diazo compound of 1-amino-2-hydroxynaphthalene sulphonic acids with normal sulphite, e.g. sodium sulphite in the presence or absence of a metal, e.g. copper powder, zinc or aluminium or a metal salt, e.g. copper sulphate. By heating the product with water or acids, e.g. dilute mineral acid, e.g. sulphuric acid or strong organic sulphonic acids such as naphthalene sulphonic acid, the sulphonic acid group introduced in place of amino in position 1 is split off. In examples: (1) 2-hydroxynaphthalene: 1-4-disulphonic acid is prepared by heating sodium 1-diazo-2-hydroxy naphthalene-4-sulphonate prepared by the process described in Specification 10235/04, [Class 2], with a solution of sodium sulphite and copper sulphate containing copper powder. The hot liquid is filtered, acidified with hydrochloric acid and the product salted out; (2) 2-naphthol-1 : 6 - disulphonic acid is prepared from 1-diazo-2-hydroxynaphthalene-6-sulphonic acid made by the process described in Specification 10235/04 by treating with sulphite copper sulphate and copper powder; 1-diazo-2-naphthol - 4 : 6 - disulphonic acid behaves similarly; (3) 6-nitro-2-hydroxynaphthalene-1-4-disulphonic acid is obtained from the sodium salt of 6-nitro-1-diazo-2-hydroxynaphthalene-4-sulphonic acid obtained as described in Specification 15418/04, [Class 2], by heating with sulphite and copper powder. The 6-nitro-2-hydroxy naphthalene - 1 : 4 - disulphonic acid may be reduced with iron to the corresponding amino compound; (4) the sodium salt of 6-bromo-2-hydroxy naphthalene-1 : 4-disulphonic acid is obtained when the sodium salt of 6-bromo - 1 - diazo - 2 - hydroxynaphthalene - 4-sulphonic acid made according to Specification 3508/11, [Class 2 (iii)], is treated with sodium sulphite, crystallized copper sulphate and copper powder. 6-Chloro-1-diazo-2-hydroxynaphthalene - 4 - sulphonic acid described in Specifications 20072/11 and 20073/11, [both in Class 2 (iii)], behaves analogously. |
| priorityDate | 1936-09-11-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 62.