Hydrogen Bromide → (S)-2-methyl-1,2,3,4-tetrahydroquinolin-5-ol hydrobromide

Temperature

100 °C

A 500-mL round bottomed flask equipped with a heating mantle and an overhead stirrer was charged with (S)-5-methoxy-2-methyl-1,2,3,4-tetrahydroquinoline hydrochloride (20 g, 94 mmol) followed by hydrobromic acid (48%, 154 mL, 1361 mmol). The mixture was heated to 100° C., and the reaction readily proceeded with loss of bromomethane through an uncooled reflux condenser. After 1 h, solids precipitated from the solution. The reaction was complete after 10 h at 100° C. and allowed to cool to ambient temperature while stirring overnight. The reaction mixture was placed in an ice bath and stirred for 2 h at 0-5° C. The resulting white slurry was filtered and the pot and solids were washed with 20 mL of ice cold water. The filter cake was dried on a Buchner funnel under nitrogen blanket to afford (S)-2-methyl-1,2,3,4-tetrahydroquinolin-5-ol hydrobromide (21.71 g, 95%) as a white powder. MS (ES, m/z): 164 [M+H]+

1. customA 500-mL round bottomed flask equipped with a heating mantle and an overhead stirrer
2. customthe reaction
3. customsolids precipitated from the solution
4. waitThe reaction was complete after 10 h at 100° C.
5. temperatureto cool to ambient temperature
6. customThe reaction mixture was placed in an ice bath
7. stirringstirred for 2 h at 0-5° C
8. filtrationThe resulting white slurry was filtered
9. washthe pot and solids were washed with 20 mL of ice cold water
10. customThe filter cake was dried on a Buchner funnel under nitrogen blanket

ORD record

ord-84cdf76b86674f1dbefe958ba54436f2

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09388161B2