1. Preparation of 1-(3-bromopropyl)-4-chlorobenzene
a. Triphenylphosphine (7.42 g, 28.3 mmol) was dissolved in dichloromethane (200 mL) and cooled at 0 °C.
b. A solution of bromine (1.46 mL, 28.3 mmol) in dichloromethane (40 mL) was slowly added to the above cooled solution over 30 min.
c. A dichloromethane (20 mL) solution of 3-(4-chlorophenyl)propan-1-ol (4.6 g, 27 mmol) was added.
d. Gradually warm the reaction mixture to room temperature with continuous stirring for 24 hours.
e. The reaction mixture was transferred to a partition funnel and washed sequentially with saturated sodium bicarbonate solution, water and brine.
f. The organic layer was dried with anhydrous sodium sulfate and subsequently concentrated.
g. The residue was purified by silica gel column chromatography (silica gel size: 230-400 mesh, 350 g; eluent: 7.5% ethyl acetate/hexane) to afford 6.15 g (97% yield) of the target product 1-(3-bromopropyl)-4-chlorobenzene as a clear, colorless oil.
h. Product characterization data:
- NMR hydrogen spectrum (400 MHz, CDCl3) δ 2.16 (2H, m), 2.77 (2H, t), 3.41 (2H, t), 7.15 (2H, d), 7.27 (2H, d). h. Product characterization data.
- HPLC retention time: 5.1 min (Method A).
