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US 5,312,970 AGranted
Method of preparing D-propoxyphene
AssigneeMallinckrodt Specialty Chemicals Company
InventorJohn R. Duchek
Life of this patent
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Abstract
D-propoxyphene can be prepared by reacting d-oxyphene and propionic anhydride. Preferably, an excess of propionic anhydride is used. The reaction easily proceeds at temperatures of 70.degree. to 80.degree. C. and produces yields exceeding 95 percent of theory. The free base d-propoxyphene can easily be converted in high yields to its hydrochloride or napsylate salts, both analgesics.
Claims22
A method of preparing d-propoxyphene comprising
- (a) dissolving d-oxyphene in propionic anhydride solvent so as to form a solution of said d-oxyphene in said propionic anhydride, which solution is substantially free of other non-aqueous solvent;
- (b) reacting said d-oxyphene with said propionic anhydride in said solution under acylating conditions at a temperature of from about 70.degree. to about 80.degree. C. so as to form d-propoxyphene;
- and
- (c) thereafter isolating d-propoxyphene from the solution.
1 more element
A method of preparing d-proxyphene comprising
- (a) dissolving d-oxyphene in propionic anhydride solvent so as to form a solution of said d-oxyphene in said propionic anhydride, which solution is substantially free of other non-aqueous solvent;
- (b) reacting said d-oxyphene with said propionic anhydride in said solution under acylating conditions at a temperature within the range of between 50.degree. C. to about 120.degree. C., but no higher than 90.degree. C., so as to form d-propoxyphene;
- and
- (c) thereafter isolating d-propoxyphene from the solution.
1 more element
Dependencies are inferred from the claim text.