Reaction #2487438

Reaction equation

p-Toluenesulfonyl chloride

(3,5-difluoropyridin-2-yl)methanol

potassium hydroxide

→

crude material

(3,5-Difluoropyridin-2-yl)methyl 4-methylbenzenesulfonate

Solvents

tetrahydrofuran

Conditions

Workup

1. 1
   workup.ADDITIONwas added slowly at RT
2. 2
   OtherAfter complete consumption of the starting material (by TLC)
3. 3
   workup.ADDITIONthe reaction mixture was diluted with H2O (50 mL)
4. 4
   Extractionextracted with EtOAc (2×25 mL)
5. 5
   WashThe combined organic extracts were washed with H2O (25 mL) and brine (25 mL)
6. 6
   Dryingdried over anhydrous Na2SO4
7. 7
   Concentrationconcentrated under reduced pressure

Procedure

To a solution of (3,5-difluoropyridin-2-yl)methanol (0.25 g, 0.7 mmol) in tetrahydrofuran (THF; 10 mL) was added potassium hydroxide (KOH; 0.14 g, 2.55 mmol) at RT, and the mixture was stirred for 15 min p-Toluenesulfonyl chloride (0.42 g, 2.21 mmol) was added slowly at RT, and the reaction mixture was stirred for another 18 h. After complete consumption of the starting material (by TLC), the reaction mixture was diluted with H2O (50 mL) and extracted with EtOAc (2×25 mL). The combined organic extracts were washed with H2O (25 mL) and brine (25 mL), dried over anhydrous Na2SO4 and concentrated under reduced pressure to obtain the crude material. Purification by silica gel column chromatography eluting with 15% EtOAc/hexane afforded compound I-5 (0.18 g, 0.25 mmol, 35%) as colorless liquid. 1H NMR (500 MHz, CDCl3): δ 8.29 (s, 1H), 7.82 (d, J=8.5 Hz, 2H), 7.34 (d, J=8.5 Hz, 2H), 7.20-7.16 (m, 1H), 5.20 (s, 2H), 2.45 (s, 3H)

Source