Benzaldehyde → 2-Hydroxy-1-(4-methoxyphenyl)-2-phenylethanone

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Reaction Conditions

Reaction Steps

According to the procedure in the literature [J. Chem. Soc. Perkin Trans. I, 1992, 2409-2417], dissolve 292 ml (2.08 mol) diisopropylamine in 3.6 litre 1,2-dimethoxyethane and cool to −78° C. Add 826 ml n-butyllithium solution (2.5 M in n-hexane, 2.066 mol) at a temperature below −60° C. Stir the mixture for a further 15 min at <−60° C. and then add a solution of 442 g (1.877 mol) (4-methoxyphenyl)[(trimethylsilyl)oxy]acetonitrile in 1.41 litre 1,2-dimethoxyethane dropwise at <−60° C. After further stirring for 30 min at −60° C., add a solution of 199.3 g (1.878 mol) benzaldehyde in 1.4 litre 1,2-dimethoxyethane in the space of 20 min at −60° C. Next, heat the reaction mixture slowly to RT in 4 h. Add 7 litre saturated ammonium chloride solution and extract with ethyl acetate. Wash the organic phase with saturated ammonium chloride solution, dry, and concentrate under vacuum. Take up the residue in 7 litre dioxan and 5 litre methanol, and add 6 litre 1 N hydrochloric acid. Stir the mixture for 3 h at RT, then add 3 litre saturated sodium chloride solution and extract the mixture with 6.5 litre ethyl acetate. Wash the organic phase with 1.0 litre 1 N sodium hydroxide solution and with saturated sodium chloride solution, dry, and concentrate under vacuum. Take up the residue in 2 litre diisopropyl ether, decant from the insoluble matter and seed with crystals. Stir the resultant suspension for 2 h at RT and then filter off the crystals with suction. Wash with 300 ml diisopropyl ether and petroleum ether and dry under vacuum. 236.8 g (47.8% of theor.) of the target compound is obtained.

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