反应 #1543063

反应方程式

bromine

3,3-dibromo-alpha-(1-methylethylidene)-2-[(5-methyl-isoxazole-3-yl)-aminosulfinyl]-4-oxo-1-azetidine acetic acid benzyl ester

bromide

→

2,3,3-tribromo-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid benzyl ester

收率 47.6%

溶剂

chloroform

反应条件

后处理

1. 1
   其他(prepared according to J. Johar, M. Zupan and B. Sket, J. Chem. Soc. Perkin Trans. I, 2059, (1982))
2. 2
   workup.ADDITIONwas added
3. 3
   其他the filtrate was evaporated to dryness

实验过程

3,3-dibromo-alpha-(1-methylethylidene)-2-[(5-methyl-isoxazole-3-yl)-aminosulfinyl]-4-oxo-1-azetidine acetic acid benzyl ester (5.61 g; 0.01 mole) was dissolved in chloroform (120 mL), bromine on a polymer carrier (12.5 g; the content of bromide bound to the polymer matrix with polyvinylpyrrolidone was 26%, 0.02 mole) (prepared according to J. Johar, M. Zupan and B. Sket, J. Chem. Soc. Perkin Trans. I, 2059, (1982)) was added and it was stirred for 12 hours at room temperature. The polymer was sucked off and the filtrate was evaporated to dryness. The obtained product was passed through a Merck 60 silica gel column with methylene chloride and thereafter 2,3,3-tribromo-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid benzyl ester (2.36 g, 47.6%) was isolated, m.p. 68°-70° C.

来源