Chlorotrimethylsilane → [2-(Furan-3-yl)ethynyl]trimethylsilane
Reaction equation
Br[C:2](Br)=[CH:3][C:4]1[CH:8]=[CH:7][O:6][CH:5]=1.[Li]CCCC.CCCCCC.[CH3:21][Si:22](Cl)([CH3:24])[CH3:23]>C1COCC1>[O:6]1[CH:7]=[CH:8][C:4]([C:3]#[C:2][Si:22]([CH3:24])([CH3:23])[CH3:21])=[CH:5]1Participants
Procedure
To a stirred and cooled (−78° C.) solution of the dibromofuran 10 (2.0 g, 7.9 mmol) in THF (20 mL) was added 1.6 M n-BuLi in hexane (10.2 mL, 16.3 mmol) over 3 min. After 1 h the cooling bath bath was removed and the mixture allowed to warm to r.t. Following a further 1.5 h the mixture was cooled back to −78° C. and then TMSCl (3.0 mL, 23.8 mmol) was added dropwise. The mixture was allowed to gradually warm up to r.t. After 19 h the mixture was poured into ice-cold Et2O-saturated aqueous NaHCO3 solution. The organic layer was separated and the aqueous layer extracted with Et2O (2×). The combined organic solutions were dried (MgSO4), filtered and concentrated to afford the crude acetylene 11 (1.83 g) as a yellow oil. This material was used in the next step without purification. 1H NMR (400 MHz; CDCl3) inter alia δ 0.23 (s, 9H), 6.44 (m, 1H), 7.34(m, 1H) and 7.63 (m, 1H).
Workup
- customAfter 1 h the cooling bath bath was removed
- temperaturethe mixture was cooled back to −78° C.
- temperatureto gradually warm up to r.t
- additionAfter 19 h the mixture was poured into ice-cold Et2O-saturated aqueous NaHCO3 solution
- customThe organic layer was separated
- extractionthe aqueous layer extracted with Et2O (2×)
- dry with materialThe combined organic solutions were dried (MgSO4)
- filtrationfiltered
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-4e382496f3f64c5a84b73fcd1bffe575
- Source dataset
- uspto-grants-2008_10
- Patent number
- US07432375B2
Reaction notes
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