3970-13-6

Bp 78 °C/0.2 mmHg; bp 98-99 °C/2.5 mmHg; n25D 1.571-1.578.

Benzyl Chloromethyl Sulfide is used for protecting group in peptide synthesis, palladium complexes, biologically active iminium compounds, sulfones, and sulfoximes.

Benzyl Chloromethyl Sulfide is obtained following the procedure of Fancher. Chloromethylation of phenylmethanethiol with paraformaldehyde in concentrated hydrochloric acid gives the desired benzyl chloromethyl sulfide. To paraformaldehyde (7.5 g) in 50 mL of benzene, 100 mL of concentrated HCl is added in 5 min with stirring. The mixture is kept at 40 °C for a while and phenylmethanethiol (33.75 g) in 50 mL of benzene is added slowly. The resulting mixture is maintained slightly above 40 °C for 2 h. After removing the solvent, the product is purified by distillation under reduced pressure. The unpleasant odor can be in large part suppressed by washing used apparatus immediately with alkaline permanganate. Other methods have been described elsewhere.

Benzyl Chloromethyl Sulfide should only be used in a fume hood.