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:
Jun. 09, 1981
Filed:
May. 19, 1978
Paul Smith, Hoddesdon, GB;
Frederick Cassidy, Harlow, GB;
Beecham Group Limited, , GB;
Abstract
A process for the preparation of a compound of the formula (A): ##STR1## wherein: R.sub.3 is a C.sub.1-5 alkyl group, a C.sub.3-6 alkenyl group, a C.sub.3-6 cycloalkyl group or an alkylphenyl group in which the alkyl moiety contains 1 to 3 carbon atoms and the phenyl moiety is optionally substituted; R.sub.4 is a hydroxyl group, or a group OR.sub.6 wherein R.sub.6 is a C.sub.2-7 acyl group, a C.sub.1-4 alkyl group, or an optionally substituted benzyl group; R.sub.5 is hydrogen or a C.sub.1-5 alkyl group; or R.sub.4 and R.sub.5 together with the carbon atom to which they are joined represent a carbonyl group; which process comprises the reaction of a compound of the formula (C): ##STR2## wherein Q is a carbonyl group protected by a reagent capable of selectively protecting the 3-carbonyl of androstenedione, and R.sub.3, R.sub.4 and R.sub.5 are as defined in formula (A), to generate an unprotected carbonyl group in place of the protected carbonyl group Q. This process has advantages over the known process for the preparation of compounds of formula (A).