Clonidine → HCID 178519725, compound

Participants

Reaction Steps

3.25 g (22.9 millimoles) of 6-hydroxy-nicotinic acid are dissolved in 600 ml of absolute tetrahydrofuran and 60 ml of absolute hexamethylphosphorotriamide, 3.8 g (22.9 millimoles) of N,N'-carbonyl-diimidazole are added and the mixture is stirred for 45 minutes at room temperature. A solution of 5.3 g (11.0 millimoles) of 2-(2',6'-dichlorophenylamino)-2-imidazoline in 100 ml of absolute tetrahydrofuran is then added dropwise and the mixture is left to stand overnight. The solvents are then stirred off under reduced pressure on a rotary evaporator, the residue is treated with 50 ml of 0.5% strength sodium bicarbonate solution and the mixture is decanted. 3.2 g of semi-crystalline, crude (6-hydroxynicotinoyl)-2-(2',6'-dichlorophenylamino)-2-imidazoline are obtained, which on recrystallization from isopropanol give a pure product of melting point 256°-258° C.

Provenance & Evidence