Reaction #3870

Reaction equation

7-Methoxy-3-piperidino-2,2-dimethylbenzofuran

HBr

→

desired product

7-Hydroxy-3-piperidino-2,2-dimethylbenzofuran

Solvents

acetic acid

Conditions

Workup

1. 1
   Temperaturethe solution refluxed for 3 hours
2. 2
   workup.ADDITIONThe reaction mixture is poured
3. 3
   OtherThe alkaline reaction mixture
4. 4
   Extractionis extracted with methylene chloride
5. 5
   Washthe organic phase washed with water
6. 6
   Otherdried
7. 7
   Filtrationfiltered
8. 8
   Otherevaporated in vacuo
9. 9
   OtherThe residue is chromatographed on silica gel eluting with ethyl acetate/hexane (1:3)

Procedure

7-Methoxy-3-piperidino-2,2-dimethylbenzofuran (65.1 g) is added to a stirred mixture of glacial acetic acid (340 ml) and 48% HBr (340 ml) and the solution refluxed for 3 hours. The reaction mixture is poured into crushed ice/H2O and brought to a pH=8-10. The alkaline reaction mixture is extracted with methylene chloride and the organic phase washed with water, dried, filtered and evaporated in vacuo. The residue is chromatographed on silica gel eluting with ethyl acetate/hexane (1:3) affording the desired product as a liquid.

Source