반응 #355180
ord-f759e12b51c94cd484dcdffb329cb362
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후처리
- 1기타followed by in vacuo removal of solvents
- 2기타In the mean time, a solution was prepared in the usual manner
- 3workup.ADDITIONwas added in 5 minutes
- 4기타followed by in vacuo removal of dichloromethane
- 5workup.ADDITIONEthyl acetate was added
- 6기타The layers were separated
- 7추출extraction
- 8추출was extracted
- 9세척The combined extracts were washed with iced water
- 10건조dried over anhydrous magnesium sulfate
- 11농축concentrated in vacuo to small volume whereupon sodium α-ethylcapronate
- 12workup.ADDITIONwas added
- 13기타etc to obtain 8.0 g (62%) of the
실험 절차
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.