反应 #355180
ord-f759e12b51c94cd484dcdffb329cb362
反应方程式
反应物
试剂
反应条件
后处理
- 1其他followed by in vacuo removal of solvents
- 2其他In the mean time, a solution was prepared in the usual manner
- 3workup.ADDITIONwas added in 5 minutes
- 4其他followed by in vacuo removal of dichloromethane
- 5workup.ADDITIONEthyl acetate was added
- 6其他The layers were separated
- 7萃取extraction
- 8萃取was extracted
- 9洗涤The combined extracts were washed with iced water
- 10干燥dried over anhydrous magnesium sulfate
- 11浓缩concentrated in vacuo to small volume whereupon sodium α-ethylcapronate
- 12workup.ADDITIONwas added
- 13其他etc to obtain 8.0 g (62%) of the
实验过程
A solution of crude benzyloxy (ethyloxy)phosphinyl isocyanate [(C6H5CH2O) (C2H5O)P(O)-NCO] in 30 ml of dry dichloromethane was prepared by reaction of 30 mmol of crude benzyloxy(ethoxy) phosphinylamide [(C6H5CH2O) (C2H5 0)P(O)--NH2 ] with phosgene in toluene in the presence of pyridine followed by in vacuo removal of solvents. According to an IR spectrum, the solution contained approximately 20 mmol of the isocyanate. In the mean time, a solution was prepared in the usual manner starting from 7.0 g (20 mmol) of D(-) ampicillin, 5.0 ml of BSA and 30 ml of dichloromethane. This solution was cooled down to 0°C whereupon the solution of the isocyanate was added in 5 minutes and according to thin-layer chromatograms, ampicillin was about two thirds converted into the desired penicillin. The reaction mixture was poured in iced water of pH 7.0, followed by in vacuo removal of dichloromethane. Ethyl acetate was added and the pH lowered to 3.5. The layers were separated and extraction was continued until the greatest part of the penicillin was extracted. The combined extracts were washed with iced water, dried over anhydrous magnesium sulfate, concentrated in vacuo to small volume whereupon sodium α-ethylcapronate was added, etc to obtain 8.0 g (62%) of the above named sodium salt in good state of purity.