Hydrochloric Acid → 4-[(1,3-Dithian-2-ylidene)(phenyl)methyl]phenol

Participants

Reaction Steps

To a solution of 2-trimethylsilyl-1,3-dithiane (29.1 g) in dry tetrahydrofuran (600 ml) is added at -65° a 1.4M solution of n-butyllithium in hexane (108 ml). The reaction mixture is progressively warmed to 0° during 4 hours and cooled to -65°. A further 1.4M solution of n-butyllithium in hexane (108 ml) and a solution of 4-hydroxybenzophenone (30.0 g) in dry tetrahydrofuran (180 ml) are added, the temperature being maintained under -60°. The reaction mixture is progressively warmed to room temperature overnight. The suspension is slowly poured into water (2 l) and acidified to pH 2 with hydrochloric acid (32%). The compound is immediately extracted with ethyl acetate (4×500 ml). The combined organic solutions are washed with water (3×250 ml) and dried over magnesium sulphate. The solvent is evaporated in vacuo. The residue is washed with hexane (3×50 ml) and then recrystallized from carbon teytrachloride. The product is dried in vacuo to constant weight to give (1,3-dithian-2-ylidene)-(4-hydroxyphenyl)-phenylmethane, m.p. 135°-137°.

Provenance & Evidence