Tetrahydrofuran → 3-Bromo-4-fluoro-α,α-dimethylbenzeneacetaldehyde

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4]([C:9]([CH3:13])([CH3:12])[C:10]#N)[CH:5]=[CH:6][C:7]=1[F:8].CC(C[AlH]CC(C)C)C.C1C[O:26]CC1>>[Br:1][C:2]1[CH:3]=[C:4]([C:9]([CH3:13])([CH3:12])[CH:10]=[O:26])[CH:5]=[CH:6][C:7]=1[F:8]

Participants

Reactant 3

HCID 8028Tetrahydrofuran

HCID 14487Diisobutylaluminum hydride

HCID 667410412-(3-Bromo-4-fluorophenyl)-2-methylpropanenitrile

Product 1

HCID 866622533-Bromo-4-fluoro-α,α-dimethylbenzeneacetaldehydeYield 92%

Procedure

To a stirred solution of 2-(3-bromo-4-fluorophenyl)-2-methylpropanenitrile (29 g, 120 mmol) in THF (500 mL) at −78° C. was dropwise added DIBALH (1M in toluene, 360 mL, 3 eq) over 2 h. After the reaction mixture was stirred at same temperature for 30 minutes, it was allowed to warm to room temperature. After the reaction was complete, the mixture was quenched by 1N HCl and extracted with EA. The separated organic layer was dried over MgSO4 and evaporated in vacuo to give 2-(3-bromo-4-fluorophenyl)-2-methylpropanal (27 g, 92%). 1H NMR (400 MHz, CDCl3) δ 9.46 (s, 1H), 7.47-7.44 (m, 1H), 7.19-7.15 (m, 1H), 7.12 (t, J=8.4 Hz, 1H), 1.45 (s, 6H).