http://rdf.ncbi.nlm.nih.gov/pubchem/patent/ES-398732-A1
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_1e70c0aeade92d7571d955d3b90ea06e |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/A61K31-56 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/A61K31-58 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07J1-00 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C- http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07J71-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/A61K- |
| filingDate | 1972-01-10-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1975-06-01-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | ES-398732-A1 |
| titleOfInvention | A PROCEDURE FOR THE PREPARATION OF A 16,17-CETAL OF BETA -3,20-DICETO-6,6-DIFLUOR 16 ALPHA, 17 ALPHA, 21-TRIHYDRO-XIPREGNANE. |
| abstract | A procedure for the preparation of a 16,17-ketal of δ 4-3,20-diceto-6,6-difluor-16α17α21-trihydroxypregnan of general formula: **(See formula)** where R2 and R3 are individually a C1-C6 alkyl C5-C6 cycloalkyl or phenyl group; but R2 and R3 attached may be tetramethylene or pentamethylene; whose procedure consists essentially of the following successive stages: (a) contacting an asteroid compound of formula: **(See formula)** where R2 and R3 have the meaning given above and R1 and R4 are individually a C1-C5 alkyl group, with NOF or a mixture of NOF and NOBF4, in an inert solvent at a temperature between -10º and 100ºC, under substantially anhydrous conditions, the amount of nitrosyl fluoride being at least about 2 moles per mole of the initial Δ5-steroid and the molar ratio of NOP to NOBF4 being. about 50: 1 to 1:50; thus producing the corresponding 5α-fluoro-6-nitriminosteroid; (b) contacting the solution of step (a) with a weak base to remove excess reagent and acidic by-products from the reaction and contacting the solution with neutral alumina containing from 5 to 15% by weight of water to produce the corresponding 5αfluoro-6-ketosteroid; (c) contacting the product of step (b) with a fluorinating agent selected from among sulfur tetrafluoride, selenium tetrafluoride and phenylsulfur trifluoride, in the presence of a Lewis acid selected from HF, BF3 and SbF5 at a temperature from -10 to 100ºC, in an inert solvent and under substantially anhydrous conditions; with the proviso that when sulfur tetrafluoride and HF are used, the molar ratio of HF in the mixture does not exceed about 90; thus producing the corresponding 5α, 6,6-trifluoresteroid; (d) contacting the product of step (c), dissolved in a water-miscible solvent, with an aqueous alkali at a temperature between -10º and 35ºC, to separate the acyl groups C-3 and C-21; (e) selectively acetylating the 21-hydroxyl by contacting the product of step (d) with a solution of acetic anhydride in pyridine, at a temperature not higher than about 0ºC; (f) oxidizing the 3-hydroxyl to 3-ketone by contacting the product of step (e), in solution in a water-miscible solvent, with aqueous chromic acid at a temperature not higher than about 35ºC; and (g) dehydrofluorinate the product of the step, (f) in positions C-4 and C-5, contacting it with a base selected from anhydrous neutral alumina, potassium carbonate, silver oxide, potassium hydroxide and lithium carbonate in a solvent selected from methanol and ethanol, at a temperature that can be up to approximately the reflux of the solvent. (h) hydrolyze the 21-acetyl group by contacting the product from step (g) with an aqueous base. (Machine-translation by Google Translate, not legally binding) |
| priorityDate | 1971-01-11-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 49.