反应 #1543065

反应方程式

bromine

3,3-dibromo-alpha-(1-methylethylidene)-2-[benzylaminosulfinyl]-4-oxo-1-azetidine acetic acid benzyl ester

bromine

→

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

收率 55.0%

溶剂

chloroform

反应条件

后处理

1. 1
   workup.ADDITIONwas added
2. 2
   其他the filtrate was evaporated to dryness

实验过程

3,3-dibromo-alpha-(1-methylethylidene)-2-[benzylaminosulfinyl]-4-oxo-1-azetidine acetic acid benzyl ester (5.7 g; 0.01 mole) was dissolved in chloroform (120 mL), bromine on a polymer carrier (18.75 g; the content of bromine bound to the polymer matrix with polyvinylpyrrolidone was 26%, 0.03 mole) was added and it was stirred at room temperature for 48 hours. Then the polymer was sucked off and the filtrate was evaporated to dryness. The evaporated residue was passed through a silica gel column with methylene chloride to isolate 2,3,3-tribromo-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid benzyl ester (2.73 g; 55.0%), which was subjected to a reaction with silver tetrafluoroborate in methanol analogously to the reaction described under 1a. After isolation 3,3-dibromo-2-methoxy-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid benzyl ester with spectroscopic data identical to those disclosed under 1a was obtained.

来源