反应 #1543066

反应方程式

anisole

hydrochloric acid

aluminum trichloride

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

→

3,3-dibromo-2-methoxy-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid

溶剂

methylene chloride

Ethyl acetate

methylene chloride

反应条件

后处理

1. 1
   workup.ADDITIONwas added
2. 2
   其他the layers were separated
3. 3
   萃取The ethyl acetate layer was extracted with a 5% sodium hydrogen carbonate solution (2×20 mL)
4. 4
   其他the layers were separated
5. 5
   workup.ADDITIONfresh ethyl acetate (20 mL) and sodium chloride were added
6. 6
   其他the layers were again separated
7. 7
   洗涤The ethyl acetate layer was washed with a saturated salt solution
8. 8
   其他dried
9. 9
   其他evaporated to a dry residue

实验过程

To an ice-cooled suspension of aluminum trichloride (0.400 g; 0.003 mole) in methylene chloride (15 mL) in a nitrogen stream a solution of 2-methoxy-3,3-dibromo-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid benzyl ester (0.447 g; 0.001 mole) and anisole (0.648 g; 0.65 mL, 0.006 mole) in methylene chloride (15 mL) was added and then it was stirred for half an hour at room temperature. Ethyl acetate (15 mL) and 0.1N hydrochloric acid (5 mL) were added to the reaction mixture and the layers were separated. The ethyl acetate layer was extracted with a 5% sodium hydrogen carbonate solution (2×20 mL) and the layers were separated. The aqueous layer was acidified with 0.1N hydrochloric acid to pH 1, then fresh ethyl acetate (20 mL) and sodium chloride were added and the layers were again separated. The ethyl acetate layer was washed with a saturated salt solution, dried and evaporated to a dry residue to obtain 3,3-dibromo-2-methoxy-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid, which was identical to the one disclosed under 2a.

来源