Hydrochloric Acid → Tapentadol Hydrochloride

The product of Example 16 (1.9 g, 8 mmol) was dissolved in dichloromethane, the mixture was cooled in an ice-water bath, and a solution of boron tribromide (1.9 ml, 20 mmol) in dichloromethane was slowly added dropwise, then it was gradually raised to room temperature to make it react for 15 hrs. After it was cooled in an ice-water bath, methanol was slowly added dropwise to quench the reaction, and the organic phase was washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated to 2 mL, then the concentrated hydrochloric acid (670 Ml, 8 mmol) was added dropwise, and the mixture was concentrated and recrystallized with isopropanol and ethyl acetate to obtain the target 1.8 g, yield: 90%. [α]D=+24.3° (c=1.10, CH3OH). 1HNMR (300 MHz, CD3OD): δ 7.2 (1H, t, J=7.9, 15.6), 6.6-6.8 (3H, m), 2.8-2.9 (2H, m), 2.7-2.8 (6H, br s), 2.2-2.3 (1H, m), 2.1-2.2 (1H, m), 1.8-1.9 (1H, m), 1.5-1.6 (1H, m), 1.2 (3H, d, J=6.7), 0.8 (3H, t, J=7.4, 14.4). ESI-MS: 222.4 (M+H).

1. temperaturethe mixture was cooled in an ice-water bath
2. customreact for 15 hrs
3. temperatureAfter it was cooled in an ice-water bath
4. customto quench
5. customthe reaction
6. washthe organic phase was washed with water and saturated brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated to 2 mL
9. concentrationthe mixture was concentrated
10. customrecrystallized with isopropanol and ethyl acetate
11. customto obtain the target 1.8 g, yield: 90%

ORD record

ord-fc5cc3de51754e2ba9eb9daa14d8b7f4

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09249084B2