Formaldehyde → 2-Trifluoroacetyl-7-trifluoromethyl-1,2,3,4-tetrahydroisoquinoline
Reaction equation
S(=O)(=O)(O)O.[F:6][C:7]([F:24])([F:23])[C:8]([NH:10][CH2:11][CH2:12][C:13]1[CH:18]=[CH:17][C:16]([C:19]([F:22])([F:21])[F:20])=[CH:15][CH:14]=1)=[O:9].[CH2:25]=O>C(O)(=O)C>[F:6][C:7]([F:23])([F:24])[C:8]([N:10]1[CH2:11][CH2:12][C:13]2[C:18](=[CH:17][C:16]([C:19]([F:22])([F:21])[F:20])=[CH:15][CH:14]=2)[CH2:25]1)=[O:9]Participants
Procedure
10.0 ml of concentrated sulfuric acid were slowly added dropwise to a solution of 1.77 g (6.2 mmol) of N-trifluoroacetyl-2-(4-trifluoromethylphenyl)ethylamine [prepared from 2-(4-trifluoromethylphenyl)ethylamine and trifluoroacetic anhydride at −5° C.] in 7.5 ml of glacial acetic acid, and, while cooling in ice, 2 ml of formalin solution were added dropwise. After 18 hours at room temperature, the reaction mixture was poured into 130 ml of ice-water and extracted with dichloromethane, and the combined organic phases were washed with sodium bicarbonate solution and then with water. After drying over sodium sulfate, filtration and evaporation, 1.7 g of 2-trifluoroacetyl-7-trifluoromethyl-1,2,3,4-tetrahydroisoquinoline were isolated and were converted into 7-trifluoromethyl-1,2,3,4-tetrahydroisoquinoline by heating under reflux in ethanol/3N HCl (1:1) and alkaline workup.
Workup
- temperaturewhile cooling in ice
- extractionextracted with dichloromethane
- washthe combined organic phases were washed with sodium bicarbonate solution
- dry with materialAfter drying over sodium sulfate, filtration and evaporation
Sources & evidence
- ORD record
- ord-119c6c3c5b6a49689e85d3af9134f1bd
- Source dataset
- uspto-grants-2003_08
- Patent number
- US06602867B1
Reaction notes
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