Dimethylformamide → 3-Chloro-6-(4-fluorophenyl)-1,2,4-triazine

Participants

Reaction Steps

A suspension of 20 g. of 6-(p-fluorophenyl)-1,2,4-triazin-3(2H)-one in 158 ml. of chloroform is cooled in an ice bath and 178.5 ml. of phosphorus oxychloride is added followed by 1.2 g. of N,N-dimethylformamide. The mixture is refluxed for 4.5 hours and then the excess phosphorus oxychloride is removed in vacuo. The residue is redissolved in chloroform and poured into ice-water. When the ice melts the mixture is filtered. The organic layer of the filtrate is washed with water and saturated sodium bicarbonate solution and then dried giving a brown semi-solid. This semi-solid is taken up in chloroform and filtered through a short silica gel column giving 3-chloro-6-(p-fluorophenyl)-1,2,4-triazine as a tan solid.

Provenance & Evidence