Triethylamine → 5-{[6-(4-Fluorophenyl)[1,2,4]triazolo[4,3-b]pyridazin-3-yl]sulphanyl}-2-nitroaniline

Participants

Reaction Steps

342 mg of sodium borohydride are added to a mixture of 1.76 g of commercial 3-amino-4-nitrophenyl thiocyanate in 15 cm3 of N,N-dimethylformamide. The reaction is stirred at ambient temperature for 2 h and then 746 mg of 3-chloro-6-(4-fluorophenyl)-1,2,4-triazolo[4,3-b]pyridazine and 1.25 cm3 of triethylamine are added. The resulting mixture is then heated to 95° C. and then stirred for 1 h at 20° C. After the addition of demineralized water, the mixture obtained is extracted with 3×100 cm3 of ethyl acetate (a small amount of methanol is added due to solubility problems). The organic phases are combined and then dried over magnesium sulphate and concentrated to dryness, so as to give a brown solid which is chromatographed on a 25 g Merck cartridge of silica 15-40 μm (elution with ethyl acetate). 360 mg of 5-{[6-(4-fluorophenyl)[1,2,4]triazolo[4,3-b]pyridazin-3-yl]sulphanyl}-2-nitroaniline are thus obtained in the form of a green solid, the characteristics of which are as follows:

Provenance & Evidence