反应详情

288 g of ethyl pyruvate, 250 g of benzylurethane, 2.5 g of p-toluenesulphonic acid and 1 g of hydroquinone are introduced into 2.5 l of toluene and refluxed for 9 h in a water separator. The reaction solution is then filtered through silica gel and washed with 500 ml of toluene. The filtrate is treated with 1 g of hydroquinone and concentrated to the greatest possible extent on a rotary evaporator. 376 g of ethyl N-benzyloxycarbonyl-2-amino-acrylate are obtained as an oil, which according to HPLC has a purity of about 90%.

1. filtrationThe reaction solution is then filtered through silica gel
2. washwashed with 500 ml of toluene
3. additionThe filtrate is treated with 1 g of hydroquinone
4. concentrationconcentrated to the greatest possible extent on a rotary evaporator