2,4-Dichlorobenzaldehyde → alpha-[1-(4-Methylphenyl)ethenyl]-2,4-dichlorobenzenemethanol
Reaction equation
C(C1C=C(C(C)C)C=C(C(C)C)C=1S(NN=[C:21]([C:23]1[CH:28]=[CH:27][C:26]([CH3:29])=[CH:25][CH:24]=1)[CH3:22])(=O)=O)(C)C.C[Li].[Cl:32][C:33]1[CH:40]=[C:39]([Cl:41])[CH:38]=[CH:37][C:34]=1[CH:35]=[O:36]>O1CCCC1>[CH3:29][C:26]1[CH:27]=[CH:28][C:23]([C:21]([CH:35]([C:34]2[CH:37]=[CH:38][C:39]([Cl:41])=[CH:40][C:33]=2[Cl:32])[OH:36])=[CH2:22])=[CH:24][CH:25]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
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##
Workup
- temperaturemaintaining the temperature of the mixture below -60° C
- stirringAfter stirring for 1 hour at room temperature the reaction
- customwas quenched with a saturated aqueous ammonium chloride solution
- concentrationThe reaction mixture was concentrated under reduced pressure
- dissolutionThe resulting residue was dissolved in ethyl acetate
- washwashed with saturated aqueous sodium hydrogen carbonate
- washwashed with water
- dry with materialdried over anhydrous magnesium sulphate
- concentrationconcentrated under reduced pressure
- customto yield an oil
- customThe oil was chromatographed on silica gel eluting with ethyl acetate-hexane (3:97)
Sources & evidence
- ORD record
- ord-18f79f9603ee458087ce6d540d60c2e6
- Source dataset
- uspto-grants-1986_12
- Patent number
- US04628104
Reaction notes
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