反应详情

38.5 ml of bromine dissolved in 110 ml of acetic acid are added dropwise onto a suspension of 159 g of the product of Example 1 in 1.6 l of acetic acid and 1.6 ml of hydrochloric acid, the reaction mixture is then stirred for 3 h at ambient temperature. The precipitate obtained is filtered, rinsed with water and then dissolved in dichloromcthane and dried over magnesium sulphate. The dichloromethane is evaporated off, the residue is taken up in pentane and filtered to give 100 g of the expected product. A second batch is obtained by pouring the filtrate of the reaction mixture onto an icc/water mixture, then by filtering off and by treating the precipitate as previously. The two batches are then combined and recrystallised from acetic acid.

1. customThe precipitate obtained
2. filtrationis filtered
3. washrinsed with water
4. dissolutiondissolved in dichloromcthane
5. dry with materialdried over magnesium sulphate
6. customThe dichloromethane is evaporated off
7. filtrationfiltered