反応 #355180
ord-f759e12b51c94cd484dcdffb329cb362
反応方程式
反応物
試薬
反応条件
後処理
- 1その他followed by in vacuo removal of solvents
- 2その他In the mean time, a solution was prepared in the usual manner
- 3workup.ADDITIONwas added in 5 minutes
- 4その他followed by in vacuo removal of dichloromethane
- 5workup.ADDITIONEthyl acetate was added
- 6その他The layers were separated
- 7抽出extraction
- 8抽出was extracted
- 9洗浄The combined extracts were washed with iced water
- 10乾燥dried over anhydrous magnesium sulfate
- 11濃縮concentrated in vacuo to small volume whereupon sodium α-ethylcapronate
- 12workup.ADDITIONwas added
- 13その他etc to obtain 8.0 g (62%) of the
実験手順
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.