反应详情

To a solution of triphenylphosphine (20.2 g, 77 mmol) in dry CH2Cl2 (80 mL) was added dropwise a solution of bromine (11.9 g, 77 mmol) in dry CH2Cl2 (40 mL). The stirring was continued for one hour and then a solution of compound of step 2 (23.2 g, 77 mmol) in dry CH2Cl2 (40 mL) was added dropwise. The resulting mixture left stirring for 12 hours. After removing the solvent the residue was taken up in ethyl acetate and washed with water. The organic extract was dried over MgSO4 and the solvent evaporated in vacuo. The residue was chromatographed over silica gel using toluene as eluant to give a yellow oil (21.0 g, 75 %); IR (film) 1600 cm-1, MS ((70eV): m/z 363 (M+,12.6), 129 (100).

1. waitThe resulting mixture left
2. customAfter removing the solvent the residue
3. washwashed with water
4. extractionThe organic extract
5. dry with materialwas dried over MgSO4
6. customthe solvent evaporated in vacuo
7. customThe residue was chromatographed over silica gel