Cesium fluoride → 4,4'-Dicyanobenzophenone

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Reaction Steps

15.7 g of 4-cyanobenzaldehyde and 9.1 g of caesium fluoride are added to a solution of 9.4 g of 5-trimethylsilylthiazole in 0.56 l of THF, and the mixture is heated under reflux for 16 hours. The solid material is filtered off and the solvent is concentrated. Column chromatography (SiO2, hexane/ethyl acetate 1:2) yields first (a) 5-(4-cyanobenzoyl)-thiazole [Rf hexane/ethyl acetate 1:2)=0.65], m.p. (after crystallisation from ethyl acetate) 181°-182°; 1H-NMR (CDCl3): δ (ppm)=8.88 and 8 (m,4H), 8.36 (s,1H), 9.14 (s,1H), and then (b)4-(α-hydroxy-5-thiazolylmethyl)-benzonitrile [Rf (hexane/ethyl acetate 1:2)=0.35], m.p. (after crystallisation from toluene) 115°-117°; 1H-NMR (CDCl3): δ (ppm)=3.05 (d,1H), 6.2 (d,1H), 7.58 and 7.7 (m,4H), 7.73 (s,1H), 8.78 (s,1H).

Provenance & Evidence