3-chloro-3-(4-chlorophenyl)prop-2-enal

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a cooled (-78° C.) solution of 3-(4-chlorophenyl)-3-chloroacrolein (2.0 g, 10.4 mmol, obtained according to Hauptmann et al, Tetrahedron Lett. 1968, 1317) in dry THF (30 mL) was added dropwise a 3M solution of methylmagnesium bromide in THF (3.47 mL, 10.4 mmol). After the addition was complete, the reaction mixture was stirred at -78° C. for 0.5 h. Next, saturated aqueous NH4Cl solution was added and the mixture was concentrated. The resulting aqueous residue was extracted with CHCl3, dried, filtered, concentrated and purified by flash chromatography to give 4-(4-chlorophenyl)-4-chloro-3-buten-2-ol (1.54 g, 71%) as a colourless oil: 1H NMR (300 MHz, CDCl3) δ (TMS) 7.51 (dt, Jt =2.6, Jd =8.6, 2H, arom), 7.33 (dt, Jt =2.6, Jd =8.6, 2H, arom), 6.18 (d, J=7.5, 1H, =CH), 4.93 (quint, J=6.4, 1H, CHOH), 1.39 (d, J=6.4, 3H, CHCH3). After the addition the mixture was concentrated The resulting aqueous residue was extracted with CHCl3 dried filtered concentrated purified by flash chromatography