The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 11, 1980
Filed:
Jul. 20, 1978
Georg Anner, Basel, CH;
Hansuli Wehrli, Reinach, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
An advantageous method for the manufacture of steroidal lactones of the spironolactone and canrenone type involves the following reaction sequence: bromination of a 3.beta. ,17-dihydroxy-17.alpha. -pregn-5-en-21-carboxaldehyde in basic or neutral medium, oxidation of the 5,6-dibromo compound with hexavalent chromium compounds under basic or neutral conditions, dehydrobromination with inorganic basic agents, such as lithium halides in the presence of lithium carbonate, or with organic bases, such as pyridine, oxidation of the steroid-4,6-diene compound so obtained having in the 17-position the same substituents as the starting material mentioned, with compounds of hexavalent chromium in acid solution, optionally after pretreatment with an acid or, in particular, with a thiocarboxylic acid (to introduce the 7.alpha.-acylthio group, e.g. if spironolactone is to be manufactured). The new process gives better yields than those hitherto described.