Synthesis
In a four-necked flask equipped with a stirrer, reflux device, 200 mL of ethylene glycol dimethyl ether with 0.4 g of sodium hydroxide was added, stirred and heated to 75 C. Tetraethylene glycol--bromoalkyl ether 5 g was dissolved in 50 mL of ethylene glycol dimethyl ether and added dropwise to the reaction system. Then the reaction was stirred at 75-80C for 22 h. After the reaction, the sodium bromide was filtered out and the solvent was evaporated to obtain a yellow viscous oily substance of 4.5 g. The bromine mass fraction was measured to be 0.71%. 80mL of oily material without separation directly added to 1 mol / L hydrochloric acid solution, reflux 4h, precipitated white solid. After cooling, the solid (triphenylmethanol) was filtered out and extracted with chloroform for 3-5 times, the extracts were combined, dried with anhydrous magnesium sulfate and evaporated with chloroform under reduced pressure. The residue was purified by chromatography with aluminum chloride (neutral), and the eluent was acetone-hexane (7:3, v/v). The solvent was removed by decompression evaporation to give 2-hydroxymethyl-15-crown-5 as a yellow oil, 2.03 g, in 87% yield.
