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:
Feb. 06, 1996
Filed:
Aug. 03, 1994
Applicant:
Inventors:
William A Boulanger, Schenectady, NY (US);
Michael T Flavin, Darien, IL (US);
Alla Kucherenko, Lemont, IL (US);
Abram K Sheynkman, Lemont, IL (US);
Assignee:
MediChem Research, Inc., Lemont, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ;
U.S. Cl.
CPC ...
549278 ; 549282 ; 549289 ;
Abstract
A method for preparing (.+-.)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (.+-.)-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal in the presence of an acid catalyst with heating to produce chromanone 7. Reduction of chromene 7 with sodium borohydride, in the presence of cerium trichloride, produced (.+-.)-calanolide A, which was purified chromatographically.