Fenazox

Description

Amfenac sodium is a non-steroidal antiinflammatory agent structurally related to ketoprofen,suprofen(10) and tiaprofenic acid.It is reported to be effective in the short term treatment of rheumatoidarthritis,osteoarthritis and pain associated with minor surgical procedures.

Chemical Properties

Yellow Solid

Originator

A.H. Robins (USA)

Uses

Amfenac is an antibacterial agent

Uses

Fenazox is used in the synthetic preparation of amides via reductive amidation of esters, which is used in the synthesis of bio-active molecules and natural products.

Definition

ChEBI: A hydrate that is the monohydrate of the sodium salt of amfenac.

Manufacturing Process

7-Benzoylindolin-2-one:
Method A. A mixture of 2.5 g (0.0077 mole) of ethyl 2-acetamido-3- benzoylphenylacetate in 50 ml of 3 N hydrochloric acid was refluxed for one hour. The reaction mixture was filtered and the filtrate was poured into a mixture of ice and water. The precipitate was collected and recrystallized from acetone; yield of 7-benzoylindolin-2-one 1 g (55%); melting point 154°C.
Method B. A solution of 1.3 g (0.0044 mole) of 2-acetamido-3- benzoylphenylacetic acid in 15 ml of 3 N hydrochloric acid and 15 ml of acetic acid was refluxed for three hours. The cooled solution was poured into ice water and the 7-benzoylindolin-2-one which precipitated was collected and dried.
2-Amino-3-benzoylphenylacetic acid:
A mixture of 1.0 g (0.004 mole) of 7-benzoylindolin-2-one was added to 30 ml of 3 N sodium hydroxide and the basic solution was refluxed for 45 min under nitrogen. The mixture was filtered and the filtrate was neutralized with glacial acetic acid. The precipitate was filtered off, washed with water and dried. The 2-amino-3-benzoylbenzeneacetic acid melted at 122°C (dec.). The yield was 0.8 g (72%).

brand name

FENAZOX

Therapeutic Function

Antiinflammatory

General Description

Amfenac (Fenazox), its amide prodrug, nepafenac (Nevanac),and the related analog, bromofenac, are amphoteric becauseof the presence of an additional aromatic amine group.They are less likely to be absorbed into the general circulation.They are approved for use as topical ocular anti-inflammatoryagents for the treatment of postoperative ocular pain,inflammation, and posterior segment edema. The only observedside effects of these drugs are all related to tissuesaround the eye including abnormal ocular sensation, eye rednessand irritation, burning and stinging, and conjunctival orcornea edema.

Synthesis

The reaction of 1-aminoindolin- 2-one with phenylacetone in presence of acetic acid in refluxing ethanol gives 1-(α- methylphenethylidieneimino)indolin-2-one, which by reaction with refluxing ethanolic hydrogen chloride affords ethyl α-(2-methyl- 3-phenylindol-7-yl)acetate. The ozonolysis of this intermediate in acetic acid yields ethyl 2- acetamido-3-benzoylphenyl acetate, which is cyclized by refluxing with HCl in acetic acid to give 7-benzoylindolin-2-one. Alternatively, the hydrolysis of the ester ethyl α-(2-methyl-3- phenylindol-7-yl)acetate with KOH in refluxing water affords the corresponding acid, which can be ozonolyzed as before yielding 2-acetamido- 3-benzoylphenylacetic acid. This acid can be cyclized to 7-benzoyl-1,3-dihydro-indol-2-one by refluxing with HCl in acetic acid as before .