Boron trifluoride etherate → HCID 86677136, compound

To a cooled (−78° C.) solution of thiophene (10a) (3.18 g, 37.87 mmol) in THF (20.0 mL) was slowly added n-BuLi (15.15 mL, 2.5 M solution in hexane). After 30 minutes, a solution of (S)-(−)-propylene oxide (11a) (2.0 g, 34.43 mmol) in THF (10 mL) was added followed by BF3.Et2O (4.9 g, 34.43 mmol). The resulting solution was slowly brought to room temperature and stirred for over night. The reaction was quenched with NH4Cl solution (20 mL) and extracted with ether (3×50 mL). The organic extracts were dried and solvent was distilled off. The obtained crude product was dissolved in DCM (50 mL) and DIPEA (6.67 g, 51.6 mmol) and cooled to 0° C. A solution of methanesulfonyl chloride (10.0 g, 87.3 mmol) in DCM (4.93 g, 34.43 mmol) was added and resulting mixture was stirred at room temperature for over night. The reaction mixture was washed with water (3×30 mL), dried and concentrated to give crude compound that was purified on silica gel column using 20% EtOAc/hexane to afford (1S)-1-methyl-2-thien-2-ylethyl methanesulfonate (12a, 5.2 g, 68%) 1H NMR (CDCl3) δ 1.48 (d, 3H, J=6.0 Hz), 2.71 (s, 3H), 3.05-3.22 (m, 2H), 4.85-4.95 (m, 1H), 6.90-6.98 (m, 2H), 7.19 (d, 1H, J=3.0 Hz).

1. customwas slowly brought to room temperature
2. customThe reaction was quenched with NH4Cl solution (20 mL)
3. extractionextracted with ether (3×50 mL)
4. customThe organic extracts were dried
5. distillationsolvent was distilled off
6. customThe obtained crude product
7. customresulting mixture
8. stirringwas stirred at room temperature for over night
9. washThe reaction mixture was washed with water (3×30 mL)
10. customdried
11. concentrationconcentrated
12. customto give crude compound that
13. customwas purified on silica gel column

ORD record

ord-cb248c8271b64c33aaa23b11b2b61888

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08815906B2