2369-29-1

364-30-7

2369-29-1

General procedure for the synthesis of 3,5-difluoro-1,2-phenylenediamine from 2,4-difluoro-6-nitroaniline: concentrated hydrochloric acid (10 mL) was slowly added dropwise to a mixture of 2,4-difluoro-6-nitroaniline (1.6 g, 9 mmol) and tin powder (22.5 mmol). The reaction mixture was heated to reflux for 1.5 h, subsequently cooled to room temperature and neutralized with 50% NaOH solution to pH 9-10. The precipitate was collected by filtration, dried and extracted with hot ethyl acetate (80 mL). The filtrate was subjected to secondary evaporation to give 3,5-difluoro-1,2-benzenediamine. Yield: 0.60 g (46%); the product was brown crystals; melting point 55-57 °C; Rf value was 0.86.