Imidazole → 5-(2-Benzyloxy-4-iodomethylphenyl)-1,1-dioxo-2-(2-trimethylsilanylethyl)-1,2,5-thiadiazolidin-3-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To slurry of resin-bound PPh3 (850 mg, 2.5 mmol) in DCM (10 mL) at 0° C., in a pressure vessel, is added imidazole (200 mg, 2.8 mmol) and iodine (650 mg, 2.5 mmol). The mixture is vigorously stirred at 0° C. for 30 min. To the mixture is added a solution of 5-(2-benzyloxy-4-hydroxymethylphenyl)-1,1-dioxo-2-(2-trimethylsilanylethyl)-1,2,5-thiadiazolidin-3-one (550 mg, 1.2 mmol) in DCM (10 mL) dropwise. The vessel is sealed and heated to 45° C., with stirring, for 2 h. The reaction is allowed to cool to ambient temperature and the mixture is filtered through a plug of cotton to remove the resin. The organic solution is washed with saturated Na2SO3 and saturated NaCl, then dried over MgSO4. The solvent is removed under reduced pressure to afford 5-(2-benzyloxy-4-iodomethylphenyl)-1,1-dioxo-2-(2-trimethylsilanylethyl)-1,2,5-thiadiazolidin-3-one as a white solid, which is used in the next step without further purification: MS (M+H)+=576.

Herkunft & Nachweise