Hydrochloric Acid → Irampanel

Participants

Reaction Conditions

Reaction Steps

2.38 g of 5-(2-hydroxyphenyl)-3-phenyl-1,2,4-oxadiazole are dissolved in 100 ml of anhydrous dioxane and stirred with 0.3 g of 80% sodium hydride suspension in oil for 15 minutes at 25-30° C. To this solution is added 60 ml of anhydrous dioxane, the resulting mixture is combined with 2.88 g of 2-(N,N-dimethylamino)ethylchloride hydrochloride and 0.6 g of 80% sodium hydride suspension in oil. This solution is also stirred for 15 minutes at 25-30° C. The combined solutions are refluxed for 8 hours, left to stand overnight and evaporated down in vacuo. The residue is mixed with water and 20 ml of 1N sodium hydroxide solution and extracted with ethyl acetate. The organic phase is dried over sodium sulphate, the solvent evaporated in vacuo and the residue chromatographed on silica gel with ethyl acetate/isopropanol (70:30, mixed with 2.5% of a 25% ammonia solution). The base thus obtained is dissolved in anhydrous ethanol, acidified with ethereal HCl and precipitated with diethyl ether. The residue is recrystallised from anhydrous ethanol and diethylether. Yield: 2.2 g (64% of theory). m.p.: 186-187° C.

Provenance & Evidence