关于头孢地尼的合成? 美国专利4093723，7－aca反应完毕，冰水浴，用3mol/l的hcl调ph＝1.8，再用etoac萃取。 附送尼西上7位侧链英文文献 to a solution of 1.26 g. (15 mmol.) of sodium bicarbonate in 75 ml. of acetone and 50 ml. of water at 5.degree. was added 2.1 g. (5 mmol.) of 7-amino-3-[1-(2-sulfamoylethyl)tetrazol-5-ylthiomethyl]-3-cephem-4-carboxy lic acid. the solution was cooled to -10.degree. and a solution of 1.55 g. (5.5 mmol.) of d-o-dichloroacetylmandeloyl chloride in 25 ml. of acetone was added. the reaction mixture was stirred for 30 minutes in the cold while maintaining the ph at 7.2 by addition of aqueous sodium bicarbonate, then for 1.5 hours at 25.degree.. the mixture was extracted with ether and the aqueous phase was brought to ph 9.3 with 5% sodium carbonate and stirred for 1.5 hours at 25.degree.. the aqueous mixture was extracted with ether, the ph adjusted to 4.5 and the solution was again extracted with ether. the aqueous phase was acidified to ph 1.5 with dilute hydrochloric acid and it was extracted with ethyl acetate. evaporation of the extract to dryness gave a solid which was suspended in ethyl acetate and filtered. the filtrate was diluted with ether and petroleum ether to precipitate the title compound. 查看更多
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