4-Bromo-2-hydroxybenzaldehyde → HCID 67880459, compound

Participants

Reaction Steps

To a suspension of ethyltriphenylphosphonium bromide (8.44 g, 22 mmol, 2.2 eq.) in toluene (60 mL), a solution of potassium tert-butoxide (2.60 g, 22 mmol, 2.2 eq.) in THF (15 mL) was added dropwise. The resulting red mixture was stirred at r.t. for 4 hours. The mixture was then cooled to −78° C. and a solution of 4-bromo-2-hydroxybenzaldehyde (2.12 mg, 10 mmol, 1.0 eq.) in toluene (10 mL) was added dropwise. The resulting solution was allowed to slowly warm to r.t. and further stirred at r.t. for 20 hours. The reaction was quenched with sat. aq. NH4Cl soln. (30 mL). The mixture was diluted with water (30 mL). The layers were separated and the aq. phase was extracted with Et2O (3×30 mL). The comb. org. phases were dried over MgSO4 and concentrated in vacuo. The residue was purified by flashmaster (column: 100 g, flow: 45 mL/min, 40 fractions of 45 mL, Heptane to Heptane/AcOEt 8:2) to yield 5-bromo-2-(propenyl)-phenol as a yellow oil as an unseparable mixture of E- and Z-isomer (ca. 85:15).

Provenance & Evidence