Putrescine Dihydrochloride → N'-(2,4-difluorophenyl)butane-1,4-diamine

Participants

Reaction Conditions

Reaction Steps

1,4-Diaminobutane dihydrochloride (0.97 g, 6 mmol), sodium t-butoxide (1.87 g, 19.5 mmol), rac-BINAP (61.0 mg, 0.09 mmol), and Pd(dba)2 (35.0 mg, 0.06 mmol) are charged to a flame dried screw-cap vial. The vial is vacuumed and back filled with nitrogen. Then anhydrous toluene (15 mL) is added, followed by the addition of 1-bromo-2,4-difluorobenzene (0.34 mL, 3.00 mmol). The mixture is stirred under nitrogen at 110° C. overnight. The reaction mixture is diluted with 80 mL of diethyl ether and filtered through a pad of celite 545. The filtrate is extracted with 6N aqueous HCl (10 mL×3). The combined aqueous layers are washed twice with diethyl ether and adjusted with 1M aqueous NaOH to pH>12. The aqueous layer was extracted with diethyl ether three times. The combined ether phase is dried over anhydrous Na2SO4, filtered, and concentrated to obtain N′-(2,4-difluorophenyl)butane-1,4-diamine as a brown oil: 1H NMR (CDCl3) δ 1.55 (m, 2H), 1.66 (m, 2H), 2.74 (t, 2H), 3.12 (t, 2H), 6.55 (m, 1 H), 6.73 (m, 2H).

Provenance & Evidence