反应详情

温度

60 °C

25.7 g of the thus obtained 2,5-dimethyl-3-nitro-O-benzylphenol are added in portions during stirring to a mixture of 17 g freshly prepared potassium-tert.-butylate and 120 ml oxalic acid diethyl ester. After completion of the addition, the mixture is heated to 60° C. for two hours. After cooling, the composition is mixed with 200 ml ether and carefully acidified with diluted acetic acid. The ether phase is washed with neutral water, dried and evaporated. The still present oxalic ester is distilled off in the water jet vacuum at increased bath temperature. The residue is dissolved in ether and the solution is carefully mixed with ligroin. After aspirating and drying, there is obtained 30.6 g (~85° of theory) 2-benzyloxy-4-methyl-6-nitro-phenyl pyruvic acid ethyl ester; m.p. 80°-82° C.

1. additionAfter completion of the addition
2. temperatureAfter cooling
3. washThe ether phase is washed with neutral water
4. customdried
5. customevaporated
6. distillationThe still present oxalic ester is distilled off in the water jet vacuum
7. temperatureat increased bath temperature
8. dissolutionThe residue is dissolved in ether
9. additionthe solution is carefully mixed with ligroin
10. customdrying