http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-687801-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/C07C309-41 |
| filingDate | 1950-11-24-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1953-02-18-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-687801-A |
| titleOfInvention | Manufacture of derivatives of hydroxynaphthalene sulphonic acids |
| abstract | The invention comprises: (a) the disodium salt of an ester-like anhydride of 1-hydroxy-naphthalene-2 : 3 : 4 : 6-tetrasulphonic acid of the probable formula <FORM:0687801/IV (b)/1> (b) the preparation of (a) or the free acid formulated above by treating 1-hydroxynaphthalene-3 : 6-disulphonic acid or a salt thereof with sulphuric acid containing free sulphur trioxide at a raised temperature, and, if desired, isolating the disodium salt of the product by adding the reaction mass to a mixture of ice and common salt, separating the crystals formed, washing (e.g. with methanol) and drying; (c) a product containing a hydroxy group in place of the 3-sulphonic acid group, when obtained by treating either of the products of (b) with non-caustic alkalis; (d) 1 : 3-dihydroxynaphthalene-6-sulphonic acid when obtained by the procedure of (c) followed by acid hydrolysis to remove the 2- and 4-sulphonic acid groups. The sulphonation in (b) is preferably effected at 110-130 DEG C. (e.g. 120-125 DEG C.) using sulphuric acid containing 30-66 (e.g. 40) per cent of free sulphur trioxide. The products thereof undergo the following reactions in addition to those indicated in (c) and (d): (i) direct acid hydrolysis regenerates the starting material; (ii) treatment with thionyl chloride yields 1 : 2 : 3 : 4 : 6 - pentachloronaphthalene, which can be oxidized with nitric acid to 3 : 4 : 5 : 6-tetrachlorophthalic acid; (iii) refluxing with phosphorus pentachloride and oxychloride produces a chloro-1 : 2-naphthosultone disulphochloride. In examples the disodium salt of 1-hydroxynaphthalene-3 : 6-disulphonic acid is used as starting material. |
| priorityDate | 1949-12-02-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 31.