5-Aminosalicylic Acid → Fendosal

Participants

Reaction Conditions

Reaction Steps

304 g of 5-aminosalicylic acid are added to 3800 ml of acetic acid while stirring. The stirred suspension is heated to 60° C. and 791 g of tautomeric 1-[3,4-dihydro-1-(2-oxo-2-phenylethyl)-2(1H)-naphthalenylidene]pyrrolidinium bromide in equilibrium with 1-phenacyl-2-(1-pyrrolidino)-3,4-dihydronaphthalene hydrobromide are added. An additional 150 ml of acetic acid are added to the reaction mixture, which is stirred at 70° C. for 3 to 4 hours and then cooled to ambient temperature. A solid appears and is collected by filtration, washed successively with acetic acid and petroleum ether and dried for 16 hours under vacuum to give 3-(3-carboxy-4-hydroxyphenyl)-4,5-dihydro-2-phenylbenz[e]indole.

Provenance & Evidence