3-Methoxybenzaldehyde → 2-Chloro-alpha-(3-methoxyphenyl)-3-pyridinemethanol

Beteiligte Stoffe

Reaktionsschritte

71.5 ml of a 2.1N solution of n-butyllithium in hexane are added to 19.2 g 3-bromo-2-chloropyridine (obtained according to J. D. Cook et. al. J. Chem. Soc., Section C, 1969 1973-8) in 300 ml anhydrous ether at -60° C. and under a static nitrogen atmosphere. To this freshly prepared solution of 2-chloro-3-pyridyllithium, a solution of m-anisaldehyde (13.6 g) in 100 ml anhydrous ether is added dropwise. The reaction mixture is stirred for 1 hr. at -60° C. and then is added to ice:water. The organic phase is separated and the aqueous phase is extracted with ether. The combined organic solutions are washed with water, dried (MgSO4) and solvent evaporated. The crude oil is chromatographed over SiO2 and eluted with chloroform, obtaining 14.9 g of title product as an oil which spontaneously crystallises. Recrystallisation from methanol:water affords pure product, m.p. 114°-5° C.; Cl 14.65 (14.20).

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