Benzoate → Cyclohexanol, 2-((dimethylamino)methyl)-1-(3-methoxyphenyl)-, hydrochloride (1:1)
Reaction equation
[CH3:1][N:2]([CH2:4][CH:5]1[C:10]([OH:19])([C:11]2[CH:16]=[C:15]([O:17][CH3:18])[CH:14]=[CH:13][CH:12]=2)[CH2:9][CH2:8][CH2:7][CH2:6]1)[CH3:3].C([O-])(=O)C1C(=CC=CC=1)O.C([O-])(=O)C1C=CC=CC=1.[OH-].[Na+].[ClH:41].C(O)(C)C.CN(CC1C(O)(C2C=C(OC)C=CC=2)CCCC1)C>C(O)(C)C.O>[CH3:3][N:2]([CH2:4][CH:5]1[C:10]([OH:19])([C:11]2[CH:16]=[C:15]([O:17][CH3:18])[CH:14]=[CH:13][CH:12]=2)[CH2:9][CH2:8][CH2:7][CH2:6]1)[CH3:1].[ClH:41]Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 75 °C
Procedure
In a reaction flask 160 g tramadol salicylate (or benzoate) salt was stirred with about 800 ml water and pH was adjusted to 11-12 by 30% aqueous NaOH solution. The tramadol free base was extracted with toluene, washed with water, and toluene was evaporated under reduced pressure. The oil obtained (about 100 gm) was dissolved in 300 ml isopropyl alcohol. In a separate flask HCI gas was passed in isopropyl alcohol. This isopropyl alcohol-HCI solution was added to tramadol base solution in isopropyl alcohol at about 30° C. till the pH attained 3-4. The mixture was stirred, heated to about 75° C., and then cooled to 0-5° C. The precipitated product was filtered, washed with chilled isopropyl alcohol and dried to obtain 92 gm Tramadol hydrochloride (cis=99.95% & trans=0.05%).
Workup
- extractionThe tramadol free base was extracted with toluene
- washwashed with water, and toluene
- customwas evaporated under reduced pressure
- customThe oil obtained (about 100 gm)
- temperaturecooled to 0-5° C
- filtrationThe precipitated product was filtered
- washwashed with chilled isopropyl alcohol
- customdried
Sources & evidence
- ORD record
- ord-2e406fb06f2b49d1b7575553e6630f2a
- Source dataset
- uspto-grants-2008_12
- Patent number
- US07470816B2
Reaction notes
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