N-bromobutanimide → 6-bromo-3-(3-(tert-butyldimethylsilyloxy)propyl)-1,5-dimethylthieno[2,3-d]pyrimidine-2,4(1H,3H)-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-(3-(tert-butyldimethylsilyloxy)propyl)-1,5-dimethylthieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (3.0 g, 8.14 mmol) in DCM (30 mL) at 0° C. was added NBS (1.6 g, 8.95 mmol). The reaction was stirred at 0° C. for 2 h then diluted with DCM (100 mL) and washed with water (2×50 mL). The organic layer was dried over Na2SO4 and concentrated to a residue which was purified by chromatography PE/EA (1:1) to give 6-bromo-3-(3-(tert-butyldimethylsilyloxy) propyl)-1,5-dimethylthieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (3.4 g, 93.4% yield) as a white solid. LCMS: MH+ 448 and TR=2.917 min.

Provenance & Evidence