[C:1]([C:3]1[CH:8]=[C:7]([CH2:9][CH3:10])[CH:6]=[CH:5][C:4]=1[OH:11])#[N:2].[H-].[Na+].Br[C:15]([CH3:19])([CH3:18])[CH:16]=[O:17].O>CN1C(=O)N(C)CCC1>[C:1]([C:3]1[CH:8]=[C:7]([CH2:9][CH3:10])[CH:6]=[CH:5][C:4]=1[O:11][C:15]([CH3:19])([CH3:18])[CH:16]=[O:17])#[N:2]
2-Cyano-4-ethylphenol (1.47 g) was added portionwise to a stirred, ice-cooled suspension of sodium hydride (60% w/w dispersion in mineral oil, 420 mg) in DMPU (10 ml) under argon. Stirring was continued for 1 hour at ambient temperature, the mixture cooled to 4° C. and 2-bromo-2-methylpropanal (2.26 g) in DMPU (2 ml) added. Stirring was continued for 18 hours at ambient temperature. Water (50 ml) was added and the resulting mixture extracted with ether (3×50 ml). The combined extracts were washed with water (2×30 ml) and saturated brine (2×30 ml), then dried (MgSO4). Evaporation of the solvent and purification of the residual oil by flash chromatography, eluting with 20% v/v ethyl acetate in hexane, gave 2-(2-cyano-4-ethylphenoxy)-2-methylpropanal (2.04 g), as a colourless oil; NMR: 1.21 (3H, t, J=7 Hz), 1.51 (6H, s), 2.61 (2 H, q, J=7 Hz), 6.76(1H, d, J=7 Hz), 7.28 (1H, dd, J=7,2 Hz), 7.41 (1H, d, J=2 Hz), 9.85 (1H, s).
Wird geladen…
