Hydrochloric Acid → (Tetrahydro-2H-pyran-4-yl)methyl 4-methylbenzenesulfonate

Participants

Reaction Conditions

Reaction Steps

To a solution of 97 g (810 mmol) of (tetrahydro-pyran-4-yl)-methanol in 2-methyltetrahydrofuran (190 mL) are added 165 mL of 50% aqueous NaOH solution. To this stirred suspension is added dropwise with cooling a solution of p-toluene-sulfonylchloride (283 g, 1.46 mol) in 2-methyltetrahydrofuran (280 mL). The reaction is stirred at 30-35° C. for 18 h. The suspension is poured into a mixture of ice-water (280 mL) and aqueous HCl solution (37%, 203 mL). After addition of methylcyclohexane (1.4 L) and further ice-water (0.2 L), the reaction mixture is stirred for 2 h in an ice-bath. The resulting crystalline precipitate is isolated by filtration and washed with methylcyclohexane (0.5 L) and water (0.5 L). Drying under reduced pressure at 40° C. gave 216 g of toluene-4-sulfonic acid tetrahydro-pyran-4-ylmethyl ester as white crystalline solid. Yield: 99%, ES-MS: m/z 271 [M+H]; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.19-1.35 (2H, m), 1.54-1.63 (2H, m), 1.85-2.02 (1H, m), 2.45 (3H, s), 3.28-3.39 (2H, m), 3.86 (2H, d, J=6.60 Hz), 3.93 (2H, dd, J=11.37, 4.52 Hz), 7.35 (2H, d, J=9.29 Hz), 7.78 (2H, d, J=8.31 Hz)

Provenance & Evidence