反应详情

260 g (2.3 moles) of potassium tert.-butylate are added a little at a time to 200 g (1.05 moles) of N-benzylideneglycine ethyl ester and 90.5 ml (1.05 moles) of 1,2-dibromoethane in 900 ml of dry diethyl ether and 300 l of dry dimethylsulfoxide, so that the well-stirred mixture remains at from 25° to 35° C. The mixture is stirred at room temperature overnight and excess base is then neutralized by addition of 4N hydrochloric acid. The mixture is diluted with 1.5 l of water and the ethereal phase is separated off, washed with twice 300 ml of water, dried with sodium sulfate and evaporated to give 155 g (68%) of ethyl N-benzylidene-1-aminocyclopropanecarboxylate as an oil.

1. customremains at from 25° to 35° C
2. customthe ethereal phase is separated off
3. washwashed with twice 300 ml of water
4. dry with materialdried with sodium sulfate
5. customevaporated