The general procedure for the synthesis of 5-bromoisophthalonitrile from the compound (CAS: 820231-67-2): Intermediate C (34.5 g, 97.1 mmol) and thionyl chloride (250 g) were added to a round-bottomed flask, and the reaction mixture was heated and refluxed for about 1.5 hours. Upon completion of the reaction, the excess thionyl chloride was removed by distillation. Subsequently, the yellow solid obtained was purified using silica gel column chromatography (eluent: toluene). Finally, the solvent was removed from the purified mixture by reduced pressure distillation to afford 14.7 g of Intermediate D as white crystals (yield: 73.1%).
