Opren,Dista Lilly,UK,1980
A non-steroidal anti-inflammatory ophthalmic agent.
ChEBI: A monocarboxylic acid that is propionic acid substituted at position 2 by a 2-(4-chlorophenyl)-1,3-benzoxazol-5-yl group. It was used as a non-steroidal anti-inflammatory drug until 1982 when it was withdrawn from the market due to adverse side-effects inc
uding liver necrosis, photosensitivity, and carcinogenicity in animals.
The 6-benzoxazolyl analog of the 5-benzoxazolyl product is prepared as
follows:
(a) Ethyl 2-(2-p-chlorophenyl-6-benzoxazolyl)propionate: A solution of ethyl
2-(3-hydroxy-4-aminophenyl)propionate (2.5 g) in pyridine (15 ml) was
treated with p-chlorobenzoyl chloride (1.65 ml) at 5°C. After stirring for 2
hours at room temperature the solution was evaporated to dryness.
The residue was heated at 220°C until no more water was evolved, then was
allowed to cool. This yielded ethyl 2-(2-p-Chlorophenyl-6-
benzoxazolyl)propionate.
(b) 2-(2-p-Chlorophenyl-6-benzoxazolyl)propionic acid: A solution of ethyl 2-
(2-chlorophenyl-6-benzoxazolyl)propionate (4 g) in aqueous sodium hydroxide
(30 ml) was heated on a steam bath for one-half hour. On cooling the black
solution was washed with chloroform. On acidification of the black solution
with hydrochloric acid the mixture was extracted with chloroform. This
solution on evaporation yielded 2-(2-p-chlorophenyl-6-benzoxazolyl)propionic
acid, MP 196°C.
Oraflex (Lilly);90459 compound;Benoxapran;Bexopron;Compound 90459;Lilly 3794;Lilly 90459;Lrcl 3794;Oprenal.
Antiinflammatory, Analgesic
World Health Organization (WHO)
Benoxaprofen, a nonsteroidal antiinflammatory agent, was
introduced in 1980 for the treatment of rheumatic disorders. Following reports of
serious adverse effects, some of which were fatal, it was withdrawn in several
countries prior to worldwide withdrawal by the manufacturer in 1982.
Poison by ingestion, subcutaneous, and intraperitoneal routes. Moderately toxic to humans by ingestion.Human systemic effects by ingestion: jaundice and gynecomastia (excessive development of the male mammary glands), changes in kidney tubules, decreased
