http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-686614-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_def1e3044d709fb2ffad369d2666c792 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07D231-12 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07D231-54 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07D231-22 |
| filingDate | 1950-07-27-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1953-01-28-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-686614-A |
| titleOfInvention | Improvements in or relating to the preparation of aldehydes of 1:2:3-substituted pyrazolones |
| abstract | Aldehydes of the formula <FORM:0686614/IV (b)/1> where R is alkyl or aryl, R1 is aryl and R11 is alkyl, are obtained by the decomposition of quaternary salts of the formula <FORM:0686614/IV (b)/2> p where R111 is aryl and X is halogen. The decomposition may be effected (1) by boiling with aqueous caustic potash for 5 minutes or less, preferably 45-60 seconds; or (2) by treatment with aqueous potassium carbonate to give the Schiff's base of the desired aldehyde and hydrolysis of the latter with a stronger base (e.g. caustic soda) or with an acid (e.g. acetic), preferably for less than one minute. The resulting aldehyde may be purified by conversion into a functional derivative and subsequent hydrolysis of the latter. Suitable reagents for this purpose are hydroxylamine, semicarbazide, phenylhydrazine, nitrophenylhydrazine, dinitrophenylhydrazine and aminoguanidine. Hydroxylamine is preferred, the resulting oxime being hydrolysed with a mineral acid such as hydrochloric or a ketonic acid such as pyruvic. The starting materials are made by reacting the appropriate 1 : 3-disubstituted-5-pyrazolone with a diarylformamidine or aryl isocyanide to give the Schiff's base of the 1 : 3-disubstituted-5-pyrazolone-4-aldehyde, and introducing the 2-substituent by means of an alkyl halide. In the examples R is methyl or phenyl, R1 is phenyl or p-ethoxyphenyl, R11 is methyl and R111 is phenyl or p-ethoxyphenyl; (1)-(10) describe the preparation of the aldehydes by the two methods; (11)-(13) the isolation of oximes; (14), (15) and (17) phenylhydrazones; (16) nitrophenylhydrazone; (18) dinitrophenylhydrazone; example (22) shows the purification of the aldehyde as its bisulphite compound and regeneration from the latter; (23)-(26) the hydrolysis of oximes with hydrochloric or pyruvic acid; (27)-(30) the hydrolysis of semicarbazones with phthalic anhydride or with a mixture of acetic and pyruvic acids; and (31)-(33) the decomposition of phenylhydrazones with pyruvic acid or benzaldehyde, the phenylhydrazones of the latter being obtained as by-products. |
| priorityDate | 1949-07-30-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 45.