Yield:-

Reaction Conditions:

Stage #1: 1,2,4,5-tetrafluoro-3-methylbenzenewith n-butyllithium in tetrahydrofuran;hexane at -78;Schlenk technique;Inert atmosphere;
Stage #2: with sulphur at -78; for 1 h;Inert atmosphere;Schlenk technique;
Stage #3: with hydrogenchloride in water monomer at 0; for 0.166667 h;Inert atmosphere;Schlenk technique;

References:

Wang, Kang;Li, Shu-Sen;Wang, Jianbo [Chemistry - A European Journal,2022,vol. 28,# 21,art. no. E202200170] Location in patent:supporting information