1-Bromo-3-chloropropane → 1-[4-(3-Chloropropoxy)-3-methylaminophenyl]ethanone

Participants

Reaction Steps

To a stirred suspension of sodium hydride (0.87 g, 18.2 mmol of a 50% oil dispersion) in dimethylformamide (25 ml) under nitrogen and cooled to 0° in an ice-salt bath was added, dropwise, a solution of 1-(4hydroxy-3-methylamino-phenyl)ethanone (3.0 g, 18.2 mmol) dissolved in dimethylformamide (55 ml) so that the temperature did not rise above 3° C. After the addition was complete, the reaction was stirred for 80 minutes at ambient temperature. The reaction was cooled to 5° C. and a solution of 1-bromo-3-chloropropane (3.1 g, 0.0120 mol) in dimethylformamide (20 ml) was added dropwise. After this addition was complete, the ice bath was removed and the reaction was stirred at ambient temperature for 2.5 hours. Water (75 ml) was carefully added and after stirring vigorously for 5 minutes, the reaction was left to stand overnight. The aqueous mixture was extracted with ethyl acetate and the ethyl acetate extract was washed with water, dried with MgSO4, and concentrated to yield 3.9 g of a dark solid. The compound was purified by preparative HPLC to afford 2.4 g of a beige solid. This was combined with an additional sample (3.8 g total) and two consecutive recrystallizations from ethanol gave 2.1 g (31%) of 1-[4-(3chloropropoxy3-methyl-aminophenyl]ethanone as a fluffy, beige solid, m.p.=115-117° C.

Provenance & Evidence