2,6-Lutidine → 3-Fluoropropyl trifluoromethanesulfonate

To a cold (−25° C.), stirred solution of 2,6-lutidine (4.60 mL, 39.5 mmol) in DCM (30 mL) was added triflic anhydride (6.00 mL, 35.5 mmol) over 3 min. Then 3-fluoropropane-1-ol (1.61 g, 20.6 mmol) was added. The reaction mixture was warmed to room temperature for 2.5 h. The reaction mixture was then concentrated to half its volume and purified by flash chromatography (Teledyne ISCO CombiFlash, isocratic DCM, REDISEP® SiO2 120 g, detecting at 254 nM, and monitoring at 220 nM). Concentration of the appropriate fractions provided Intermediate S-3A (2.92 g, 67.4%). 1H NMR (400 MHz, chloroform-d) δ ppm 4.69 (2 H, t, J=6.16 Hz), 4.65 (1 H, t, J=5.50 Hz), 4.54 (1 H, t, J=5.61 Hz), 2.25 (1 H, dt, J=11.39, 5.86 Hz), 2.19 (1 H, dt, J=11.44, 5.94 Hz)

1. concentrationThe reaction mixture was then concentrated to half its volume
2. custompurified by flash chromatography (Teledyne ISCO CombiFlash, isocratic DCM, REDISEP® SiO2 120 g, detecting at 254 nM, and monitoring at 220 nM)
3. customConcentration of the appropriate fractions provided Intermediate S-3A (2.92 g, 67.4%)

ORD record

ord-784342a801c24aa8b65dc9a0f27c743f

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09242940B2