http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-1413946-A
Outgoing Links
Predicate | Object |
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assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_0e77f06144be4708a6ae75bd9fee56a4 |
classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C209-62 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C209-58 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C211-51 |
classificationIPCAdditional | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C09B29-00 |
classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C67-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C209-62 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C- http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C209-58 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C209-56 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C209-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C211-51 |
filingDate | 1974-03-19-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
publicationDate | 1975-11-12-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
publicationNumber | GB-1413946-A |
titleOfInvention | Method of preparing m- and p-phenylene diamine |
abstract | 1413946 Preparation of m and p phenylene diamine AKZO NV 19 March 1974 [19 March 1973] 12069/74 Addition to 1364229 Heading C2C The invention comprises a process for the preparation of m and p phenylene diamine by Hofmann degradation of isophthalic acid diamide or terephthalic acid diamide in which in a first stage isophthalic acid diamide or terephthalic acid diamide is chlorinated in dilute mineral acid aqueous suspension and the resulting N,N<SP>1</SP>-dichloroisophthalic acid diamide or N,N<SP>1</SP>-dichloroterephthalic acid diamide is then converted into m or p phenylene diamine by treatment with an alkali metal or alkaline earth metal hydroxide at elevated temperature. Preferably in the first stage the dilution of the reaction mixture is adjusted so that the hydrogen chloride formed in the process of chlorination remains almost completely dissolved in the reaction mixture up to the end of the reaction. The aqueous mineral acid medium used may be, for example, hydrochloric acid, sulphuric or phosphoric acid. Preferably the final stage is carried out using a neutral suspension of the amides and the hydrogen chloride formed as a by-product of chlorination dissolves in the reaction mixture and the reaction takes place in a dilute aqueous hydrochloric acid medium. |
priorityDate | 1973-03-19-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 37.