3-Chloro-4-hydroxy-5-methoxybenzaldehyde → 3-(3-Chloro-4-hydroxy-5-methoxy-phenyl)-1-(5-ethyl-4-phenyl-thiophen-2-yl)-propan-1-one

Beteiligte Stoffe

Reaktionsschritte

A solution of 1-(5-ethyl-4-phenyl-thiophen-2-yl)-ethanone (200 mg, 0.869 mmol) and 3-chloro-4-hydroxy-5-methoxybenzaldehyde (194 mg, 1.04 mmol) in ethanol (2 mL) and 5 N HCl in isopropanol (1 mL) is stirred at rt for 18 h. The dark green solution is diluted with water and extracted with EA. The organic extract is evaporated, dissolved in methanol (5 mL) and THF (5 mL) and treated with Pd/C (150 mg, 10% Pd). The slurry is hydrogenated under 1.8 bar of H2 for 18 h. The mixture is filtered over celite, the solvent is removed in vacuo and the crude product is purified by CC on silica gel eluting with heptane:EA 7:3 to give 3-(3-chloro-4-hydroxy-5-methoxy-phenyl)-1-(5-ethyl-4-phenyl-thiophen-2-yl)-propan-1-one (208 mg) as a colourless oil; LC-MS: tR=1.10 min, [M+1]+=401.12; 1H NMR (CDCl3): δ 7.58 (s, 1H), 7.46-7.30 (m, 5H), 6.83 (d, J=1.8 Hz, 1H), 6.67 (d, J=1.8 Hz, 1H), 3.88 (s, 3H), 3.16 (t, J=7.6 Hz, 2H), 2.98 (t, J=7.6 Hz, 2H), 2.91 (q, J=7.6 Hz, 2H), 1.30 (t, J=7.6 Hz, 3H).

Herkunft & Nachweise