Trifluoroacetic acid → 4-(3-Ethylbenzo[b]thiophen-2-yl)-1,2,5,6-tetrahydropyridine

HRID 1837482Notes

Reaction equation

HRID 1837482 reaction equation
O[C:2]1([C:15]2[S:19][C:18]3[CH:20]=[CH:21][CH:22]=[CH:23][C:17]=3[C:16]=2[CH:24](O)[CH3:25])[CH2:7][CH2:6][N:5](C(OC(C)(C)C)=O)[CH2:4][CH2:3]1.FC(F)(F)C(O)=O.C([SiH](CC)CC)C>[OH-].[Na+]>[CH2:24]([C:16]1[C:17]2[CH:23]=[CH:22][CH:21]=[CH:20][C:18]=2[S:19][C:15]=1[C:2]1[CH2:7][CH2:6][NH:5][CH2:4][CH:3]=1)[CH3:25]

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 12052TriethylsilaneHCID 129927704-Hydroxy-4-(3-(1-hydroxyethyl)benzo[b]thiophen-2-yl)-1-(t-butyloxycarbonyl)piperidine

Product 1

HCID 129927714-(3-Ethylbenzo[b]thiophen-2-yl)-1,2,5,6-tetrahydropyridineYield 72.3%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Conditions

Temperature
20 °C

Procedure

Scheme IA, Step B: 4-Hydroxy-4-(3-(1-hydroxyethyl)benzo[b]thiophen-2-yl)-1-(t-butyloxycarbonyl)piperidine (1.038 g, 2.75 mmol) was slowly added in portions to trifluoroacetic acid (6 mL). To this mixture was added triethylsilane (1.0 mL, 6.05 mmol) dropwise. The solution was stirred at 20° C. for 3 hours then diluted with 2 N sodium hydroxide and extracted 3 times with ethyl acetate. The combined organics were dried over sodium sulfate, filtered and evaporated. The residue was chromatographed (dichloromethane/20% methanol, 2% anhydrous ammonia in dichloromethane gradient eluent) to give the intermediate title compound as a yellow solid (0.484 g, 72%). FDMS m/e=244 (M++1).

Workup

  1. extractionextracted 3 times with ethyl acetate
  2. dry with materialThe combined organics were dried over sodium sulfate
  3. filtrationfiltered
  4. customevaporated
  5. customThe residue was chromatographed (dichloromethane/20% methanol, 2% anhydrous ammonia in dichloromethane gradient eluent)

Sources & evidence

ORD record
ord-54f52317173542fd966f96a097ab15c0
Source dataset
uspto-grants-2004_08
Patent number
US06784180B2

Reaction notes

Loading…