tofenacin hydrochloride

Originator

Elamol,Brocades,UK,1971

The Uses of tofenacin hydrochloride

A metabolite of Orphenadrine (O695300). An antidepressant prodrug. Ondansetron USP Related Compound C.

Manufacturing Process

A mixture of 39.5 grams of 2-methylbenzhydrol, 200 ml of β-chloroethanol and 10 ml of concentrated hydrochloric acid is boiled under reflux for 4 hours. After cooling, the reaction mixture is poured into water and extracted with petroleum ether (boiling range 40° to 60°C). The layers are separated and the ethereal solution dried with sodium sulfate. It is then filtered. The filtrate is concentrated by evaporation of the solvent. The residue is distilled under reduced pressure to give 51.0 grams (yield 98%) of β-chloroethyl-2- methylbenzhydryl ether, boiling at 156° to 158°C/2.5 mm. A mixture of 51 grams of β-chloroethyl-2-methylbenzhydryl ether and 35 grams of methylamine in 140 ml of methanol is heated for 6 hours in a closed vessel at a temperature of 125° to 135°C. After cooling, the reaction mixture is poured into water and extracted with petroleum ether (boiling range 40° to 60°C). The ether layer is separated and washed with a 2 N hydrochloric acid solution. The acidic layer is made alkaline and extracted with ether. The ethereal solution is separated and dried with sodium sulfate. After filtration, the solvent is evaporated and the residue distilled under reduced pressure. There is thus obtained 40 grams (yield 80%) of N-methylaminoethyl-2- methylbenzhydrylether boiling at 139° to 143°C/0.7 mm.
The base is dissolved in anhydrous ether, and an ethereal solution of hydrochloric acid is added to form the hydrochloride of N-methylaminoethyl-2- methylbenzhydryl ether. The salt is crystallized from a mixture of ethanol and ether. Yield is 36 grams (78%); melting point 147° to 148°C.

brand name

Tofenacin is INN and BAN.

Therapeutic Function

Psychostimulant