Ammonium Chloride → 3-Bromo-N2-cyclopropyl-4-fluorobenzene-1,2-diamine

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Reaction Steps

To a solution of 2-bromo-1,3-difluoro-4-nitrobenzene (1.19 g, 5.0 mmol) in MeCN (10 mL) were added DIPEA (1.74 mL, 10.0 mmol) and cyclopropylamine (360 mL, 5.17 mmol). The reaction mixture was stirred at RT for 4 h. The volatiles were removed under reduced pressure and the resulting residue was partitioned between DCM and water. The organic fraction was dried, concentrated in vacuo and the resulting residue taken up in a 3:1 mixture of MeOH:water (40 mL). NH4Cl (1.53 g, 28.6 mmol) and iron powder (1.06 g, 4.76 mmol) were added and the reaction mixture heated at 80° C. for 3 h. After cooling to RT, the mixture was filtered through a pad of Celite® and washed with additional MeOH. The filtrate was concentrated in vacuo and the resulting residue partitioned between DCM and an aqueous solution of NaHCO3. The organic fraction was dried and concentrated in vacuo and the resulting residue purified by column chromatography (Si—PCC, gradient 0-5% MeOH in EtOAc) to afford the title compound as a brown oil (759 mg, 62% over 2 steps). LCMS (Method C): RT 2.97 min [M+H]+ 245.02

Provenance & Evidence