反应详情

A solution of 89.1 ml of 2-bromopropionyl bromide in 95 ml of methylene chloride and a solution of 61.13 g of pyridine in 95 ml of methylene chloride are added dropwise to a suspension of 140 g of spiro[2,3-dihydro-4H-1,3-benzoxazine-2,1'-cyclohexan]-4-one in 190 ml of methylene chloride under nitrogen atmosphere at -5° C. during about 45 minutes. Then the mixture is stirred at a room temperature for 6 hours. The reaction mixture is poured into 500 ml of water and the mixture is extracted with methylene chloride. The extract is washed, dried and evaporated to remove the solvent and the residue obtained is crystallized from methanol and the crystals are collected by filtration to obtain 197.3 g of 3-(2-bromopropionyl)-spiro[2,3-dihydro-4H-1,3-benzoxazine-2,1'-cyclohexan]-4-one.

1. extractionthe mixture is extracted with methylene chloride
2. washThe extract is washed
3. customdried
4. customevaporated
5. customto remove the solvent
6. customthe residue obtained
7. customis crystallized from methanol
8. filtrationthe crystals are collected by filtration