Bromine → 2,6-dibromo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-5-one

Participants

Reaction Conditions

Reaction Steps

Example 3, 2-Bromo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-5-one (1.5 g, 5.9 mmol) was dissolved Et2O (25 mL), cooled to 0° C. and bromine (0.35 mL, 6.6 mmol) was added dropwise. The solution was stirred at 24° C. until TLC indicated reaction complete (2-18 h; scale dependent). The solvent was removed by rotory evaporation and the crude product applied to a 25 (M) Biotage® silica gel column. Gradient elution from 50-100% B (A=Hexanes; B=10% EtOAc/hex) over 500 mL and gave 2,6-dibromo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-5-one 700 mg, and 1.5 g of a second fraction containing dibromide (1:1). RT=2.2 minutes (condition 1).

Provenance & Evidence