Dimethyl Sulfide → 1-Benzyl-1,4,7,10-tetraazacyclododecane

Participants

Reaction Steps

To a suspension of 890 mg (3.07 mmol) of 1-benzyl-3,11-dioxo-1,4,7,10-tetraazacyclododecane in tetrahydrofuran under nitrogen was added 2.64 ml of 8M borane-methyl sulfide complex (21.1 mol, 7 equivalents). The mixture was heated to reflux allowing the methyl sulfide to distill out of the reaction flask. After 2 hours, the reaction was quenched by the addition of 12 ml 1.8M hydrochloric acid in methanol and refluxed for an additional 3 hours. Volatiles were removed by evaporation, and the solid resuspended in methanol and reevaporated. The product was crystallized from methanol/ethyl acetate; yield 455 mg, 37%. Mass spectrum (CI): m/e 263 (M+H).

Provenance & Evidence