Cyanogen Bromide → 6-{[6-(4-fluorophenyl)[1,2,4]triazolo[4,3-b]pyridazin-3-yl]sulphanyl}-1H-benzimidazol-2-amine

Participants

Reaction Steps

A mixture of 4-{[6-(4-fluorophenyl)[1,2,4]triazolo[4,3-b]pyridazin-3-yl]sulphanyl}benzene-1,2-diamine and of 42 mg of cyanogen bromide in 10 cm3 of ethanol is brought to reflux for 3 hours. The resulting reaction mixture is then run into a 2.5N aqueous solution of sodium hydroxide and the mixture obtained is subsequently extracted with a 90/10 mixture of ethyl acetate and methanol. The organic phases are combined then dried over magnesium sulphate and then evaporated. A yellow powder is recovered, and is chromatographed on Biotage Quad 12/25 (KP-SIL, 60 A; 32-63 μM), elution being carried out with a gradient of dichloromethane and then dichloromethane/eluent B: 95/5, 92.5/7.5, 90/10, 87.5/12.5, 85/15 (eluent B=dichloromethane/methanol/aqueous ammonia 38/17/2). 43.2 mg of 6-{[6-(4-fluorophenyl)[1,2,4]triazolo[4,3-b]pyridazin-3-yl]sulphanyl}-1H-benzimidazol-2-amine are thus obtained in the form of a whitish powder, the characteristics of which are as follows:

Provenance & Evidence