1-N-benzyl-2-fluorobenzene-1,4-diamine

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 7 g (217.3 mmol) of N-(2-fluoro-4-aminophenyl)-N-benzyl amine (4) obtained from the aforesaid process was dissolved in 500 mL dichloromethane, then 60 g (434.6 mmol) of K2CO3 was added thereto, with stirring in an ice bath for 10 minutes. 92 mL (652 mmol) Cbz-Cl was dropped slowly to the mixture over 1 hour and then the mixture was warmed to room temperature. After completion of the reaction, 200 mL water was added to the reaction solution under stirring for 1 hour. The resultant mixture was allowed to stand for separation, and the dichloromethane layer was washed in sequence with 10% diluted hydrochloric acid and NaHCO3 solution. The obtained dichloromethane layer was rotary evaporated to afford a light yellow oil, which was purified with column chromatography to obtain 80 g of a white solid, with a yield of 76.2%. was added to the reaction solution under stirring for 1 hour to stand for separation the dichloromethane layer was washed in sequence with 10% diluted hydrochloric acid and NaHCO3 solution The obtained dichloromethane layer was rotary evaporated to afford a light yellow oil, which was purified with column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 60 g (243.7 mmol) of the intermediate N-benzyl-2-fluoro-4-nitroaniline (3), 600 mL ethanol was added as a solvent. The resultant mixture was slowly heated to reflux and then 60 mL concentrated hydrochloric acid was added. After the reactant was completely dissolved, 55 g (974.6 mmol) of Fe powder was added in batches within 1 hour. Then, reflux was continued for five hours until the reaction almost completed. The mixture was cooled to room temperature and buffered to pH 8-9 with a saturated Na2CO3. Then, the mixture was filtrated, and the filtrate was evaporated to remove ethanol by rotatory evaporation. The residual water layer was extracted with ethyl acetate, and then the ethyl acetate layer was reversely extracted with 10% diluted hydrochloric acid solution. The ethyl acetate layer was discarded. The acid-water layer was adjusted to be basic with a NaOH solution and then extracted with ethyl acetate. Thus obtained ethyl acetate layer was rotary evaporated and 47 g of dark tan oily substance was obtained with a yield of 89.2%. to reflux After the reactant was completely dissolved Then, reflux was continued for five hours until the reaction Then, the mixture was filtrated the filtrate was evaporated to remove ethanol by rotatory evaporation The residual water layer was extracted with ethyl acetate the ethyl acetate layer was reversely extracted with 10% diluted hydrochloric acid solution extracted with ethyl acetate Thus obtained ethyl acetate layer was rotary evaporated 47 g of dark tan oily substance was obtained with a yield of 89.2%