Synthesis
Step 2: Synthesis of 3-(bromomethyl)tetrahydrofuran
Lithium bromide (13.6 g) was added to a solution of methyl methanesulfonate (tetrahydrofuran-3-yl) methyl ester (5.6 g) in acetone (80 mL). The reaction mixture was heated to reflux for 4 hours. Upon completion of the reaction, the solvent was removed by rotary evaporator under reduced pressure. The residue was subjected to liquid-liquid partitioning with dichloromethane and water. The organic phase was separated and dried with anhydrous magnesium sulfate. After filtration, the dichloromethane was removed by evaporation. The resulting residue was dissolved in a small amount of dichloromethane and purified by filtration through a short column of silica gel. Finally, the filtrate was concentrated to give the title compound 3-(bromomethyl)tetrahydrofuran. Yield: 3.9 g; TLC detection: Rf = 0.80 (silica gel plate, unfolding agent was cyclohexane/ethyl acetate, 1:1 volume ratio).
References
[1] Patent: WO2004/5293, 2004, A2. Location in patent: Page 69
[2] Patent: WO2006/23630, 2006, A2. Location in patent: Page/Page column 39; 65
[3] Patent: US2013/252937, 2013, A1. Location in patent: Paragraph 0432
[4] Patent: WO2013/144097, 2013, A1. Location in patent: Page/Page column 74
[5] Patent: WO2013/144098, 2013, A1. Location in patent: Page/Page column 111
