Hydrochloric Acid → 5-Methoxy-2-(pent-4-enyl)benzaldehyde

HRID 501710Notes

Reaction equation

Br[C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][C:3]=1[CH:10]([O:13]C)OC.C([Li])CCC.Br[CH2:21][CH2:22][CH2:23][CH:24]=[CH2:25].Cl>C1COCC1>[CH3:9][O:8][C:5]1[CH:6]=[CH:7][C:2]([CH2:25][CH2:24][CH2:23][CH:22]=[CH2:21])=[C:3]([CH:4]=1)[CH:10]=[O:13]

Participants

Conditions

Temperature: -78 °C

Procedure

Step AH (3): To a solution of 1-bromo-2-(dimethoxymethyl)-4-methoxybenzene (688.5 mg, 2.637 mmol) in THF (7.0 mL) at −78° C. was added n-butyl lithium (3.46 mL, 5.538 mmol). The resulting mixture was stirred at −78° C. for 15 min. 5-Bromopent-1-ene (0.31 mL, 2.637 mmol) was added by drops. The reaction mixture was warmed to rt and stirred overnight. Aqueous hydrochloric acid solution (1N) was added and the reaction mixture was stirred at rt for 3 h. The reaction was extracted with DCM. The combined organic phases were dried over Na2SO4, filtered and concentrated in vacuum. The residue was purified by silica gel chromatography to give 5-methoxy-2-(pent-4-enyl)benzaldehyde (538.6 mg, 100%) as colorless oil. LC-MS (M+H)+=205.36. 1H NMR (CDCl3, 500 MHz) δ 10.30 (s, 1H) 7.35 (d, J=3.0 Hz, 1H) 7.17 (m, 1H) 7.06 (m, 1H) 5.82 (m, 1H) 5.05-4.98 (m, 2H) 3.84 (s, 3H) 2.12 (m, 2H) 1.69 (m, 2H) 1.57 (m, 2H).

Workup

temperatureThe reaction mixture was warmed to rt
stirringstirred overnight
stirringthe reaction mixture was stirred at rt for 3 h
extractionThe reaction was extracted with DCM
dry with materialThe combined organic phases were dried over Na2SO4
filtrationfiltered
concentrationconcentrated in vacuum
customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record: ord-d5e92bd91474463e88c94ab44cd37254
Source dataset: uspto-grants-2010_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07772221B2

Reaction notes

Loading…