反应详情

A mixture of tri-n-butylphosphine (5.7 g, 28.4 mmol) in toluene (50 mL) was added dropwise to a mixture of α,α'-dibromo-p-xylene (15 g, 56.8 mmol, 2 eq.) in 200 mL of toluene under argon gas. The reaction mixture was allowed to stir for several days at room temperature under argon, after which time the tri-n-butylphosphonium bromide salt had crystallized out of solution. The crystals were filtered and washed three times each with 50 mL portions toluene and hexanes, then air dried: 1H NMR (CDCl3) δ 0.93 (t, 9H), 1.45 (m, 12H), 2.40 (m, 6H), 4.33-4.37 (d, 2H), 4.47 (s, 2H), 7.37-7.40 (d, 2H), 7.46-7.49 (dd, 2H).

1. customafter which time the tri-n-butylphosphonium bromide salt had crystallized out of solution
2. filtrationThe crystals were filtered
3. washwashed three times each with 50 mL portions toluene and hexanes
4. customair dried