Tetrahydrofuran → 1-Benzyl-4-(m-fluorobenzylidene)piperidine
Reaction equation
[Br-].[F:2][C:3]1[CH:4]=[C:5]([CH:26]=[CH:27][CH:28]=1)[CH2:6][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[Li][CH2:30][CH2:31][CH2:32][CH3:33].C([CH:41]1[CH2:46][CH2:45][NH:44][C:43](=O)[CH2:42]1)C1C=CC=CC=1.[CH2:48]1[CH2:52]OC[CH2:49]1>>[CH2:30]([N:44]1[CH2:45][CH2:46][C:41](=[CH:6][C:5]2[CH:26]=[CH:27][CH:28]=[C:3]([F:2])[CH:4]=2)[CH2:42][CH2:43]1)[C:31]1[CH:52]=[CH:48][CH:49]=[CH:33][CH:32]=1Participants
Conditions
- Temperature
- -78 °C
Procedure
To a suspension of m-fluorobenzyltriphenylphosphonium bromide (16.98 g, 0.03 mol) in 50 mL of THF was added 14.5 mL of BuLi (M=2.5 M) at −78° C. under N2. After stirring at −78° C. for 45 min., a solution of 4-benzylpiperidone (5.67 g, 0.03 mol) in 10 mL of THF was added dropwise at −78° C. under N2. The resulting mixture was allowed to warm to room temperature and stirred for another 5 hr. Then the mixture was poured into ice (100 g) and extracted with ether (3×40 mL). The combined extracts were dried over sodium sulfate. The solvent was evaporated in vacuo to give a residue, which was purified by flash chromatography, giving 0.6 g (7%) of the product as pale yellow oil. 1H NMR (CHCl3) 2.413 (m, 2 H), 2.466 (m, 2 H), 2.558 (m, 4 H), 3.558 (s, 2 H), 6.257 (s, 1 H), 6.905 (m, 3 H), 7.284 (m, 6 H).
Workup
- temperatureto warm to room temperature
- stirringstirred for another 5 hr
- extractionextracted with ether (3×40 mL)
- dry with materialThe combined extracts were dried over sodium sulfate
- customThe solvent was evaporated in vacuo
- customto give a residue, which
- customwas purified by flash chromatography
Sources & evidence
- ORD record
- ord-b7a1cf1057bd4e4ea9e0b96d06be5f00
- Source dataset
- uspto-grants-2001_04
- Patent number
- US06218404B1
Reaction notes
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