Add tert-butyl(carboxysulfonyl)triethyldiammonium hydroxide (44.23 mmol) and acetonitrile (150 mL) to a 500 mL three-necked round-bottom flask. Add the corresponding alcohol (22.12 mmol) to the reaction mixture via syringe at room temperature. Stir the reaction mixture for two minutes, then add dropwise a solution of 1,4-dioxane (8.8 mmol) in 4 M HCl over 5 minutes. Stir the resulting suspension at room temperature for 3 hours until LCMS or NMR analysis shows no unreacted α residue. Remove the solids by filtration. Concentrate the filtrate to approximately 50 mL. Cool the concentrated solution to below 10°C in an ice bath. Add concentrated HCl (222 mmol) dropwise to the reaction mixture. Keep the reaction temperature below 25°C. Stir the reaction mixture for 2 hours. LCMS or NMR analysis shows no remaining tert-butoxycarbonylaminosulfonate. Extract the reaction mixture with ethyl acetate (3 x 30 mL). Use water (3 x 50 mL) to extract the tert-butoxycarbonylaminosulfonate.
The combined organic layers were washed with a solution of 4-methoxybenzyl chloride (mL). The organic layers were dried with sodium sulfate. The residue was concentrated. The residue was purified by silica gel column chromatography using a gradient mobile phase of 0-80% ethyl acetate in hexane to give the product 4-methoxybenzyl chloride.
Figure 4-Methoxybenzyl Chloride Synthetic Route
