2,4-Dichlorobenzaldehyde → alpha-[1-(4-Methylphenyl)ethenyl]-2,4-dichlorobenzenemethanol

Participants

Reaction Steps

To a solution of 1-(4-methylphenyl)ethanone-2,4,6-triisopropylbenzenesulfonylhydrazone (6.54 g) in tetrahydrofuran (80 ml) at -70° C. was dropwise added a solution of methyl lithium (25 ml, 1.3M in ether) while stirring and maintaining the temperature of the mixture below -60° C. After 10 minutes the reaction mixture was allowed to warm to room temperature. When evolution of nitrogen from the reaction mixture ceased, a solution of 2,4-dichlorobenzaldehyde (3.48 g) in tetrahydrofuran (10 ml) was rapidly added. After stirring for 1 hour at room temperature the reaction was quenched with a saturated aqueous ammonium chloride solution. The reaction mixture was concentrated under reduced pressure. The resulting residue was dissolved in ethyl acetate, washed with saturated aqueous sodium hydrogen carbonate, washed with water, dried over anhydrous magnesium sulphate and concentrated under reduced pressure to yield an oil. The oil was chromatographed on silica gel eluting with ethyl acetate-hexane (3:97) to yield α-[1-(4-methylphenyl)ethenyl]-2,4-dichlorobenzenemethanol δ (CDCl3): 1.86 (1H,d, J=5 Hz), 2.64-2.78 (1H, dd, J=13.5 Hz, J=10 Hz), 2.92-3.04 (1H,dd, J=15 Hz, J=5 Hz), 4.8 (1H,m), 5.38 (2H,d, J=6 Hz) and 7.16-7.5 (10H,m) as a yellow oil (2.1 g) having the formula: ##STR13##

Provenance & Evidence