反応 #96235

反応方程式

N-bromosuccinimide

t-butyl 7-formamido-3-methyl-3-cephem-4-carboxylate-1-oxide

acetic acid

→

t-butyl 3-bromomethyl-7-formamido-3-cephem-4-carboxylate-1-oxide

収率 28.5%

溶媒

dichloromethane

反応条件

後処理

1. 1
   洗浄After a total exposure of 4 hours, the reaction mixture was then washed 3 times with water
2. 2
   workup.ADDITIONThe organic phase was treated with activated carbon
3. 3
   乾燥dried over magnesium sulfate
4. 4
   その他evaporated to dryness
5. 5
   ろ過after filtration
6. 6
   workup.ADDITIONa 4:1 mixture of dichloromethane and acetone as eluent

実験手順

27 g of N-bromosuccinimide were added portionwise to an ice-cold solution of 30 g of t-butyl 7-formamido-3-methyl-3-cephem-4-carboxylate-1-oxide in 1600 ml of a 1:1 mixture of acetic acid and dichloromethane under exposure to light of two tungsten lamps of 150 W over 3 hours. After a total exposure of 4 hours, the reaction mixture was then washed 3 times with water, a saturated solution of sodium bicarbonate and again with water. The organic phase was treated with activated carbon, dried over magnesium sulfate and evaporated to dryness after filtration. The residue was subjected to preparative high pressure chromatography using a 4:1 mixture of dichloromethane and acetone as eluent to obtain by evaporation to dryness of the suitable fractions 10.7 g of t-butyl 3-bromomethyl-7-formamido-3-cephem-4-carboxylate-1-oxide having the following characteristics:

出典