Guangzhou Baiyunshan Chemical Pharmaceutical Factory

An improved process for the preparation of 7-aminodesacetoxycephalosporanic acid from penicillin G potassium was presented.The ring expansion rearrangement and enzymic hydrolysis steps were modified.The yields of these two steps were 91.6% and 89.7%, resp.The new process could simplify the procedure, reduce the cost, and decrease the environment pollution compared with the old method.

One column-switching technique for improving the determination of high mol. weight impurities in cephalosporins by gel chromatog. was presented.The detection time was shortened from 3-4 h to 0.5 h.The working life of chromatog. column was prolonged by 2-3 folds by adding the cotton filter layer in.The method was simple, effective, and reliable.

5-Androstene-3β-ol-17-one-3-acetate is a key intermediate to synthesize many steroids products, such as dehydroepiandrosterone, nandrolone decanoate, estradiol, norethisterone of androgen, estrogen and progesterone.Based on the experiment research, the best process was using hydrochloric acid to replace phosphorus oxychloride.As a reaction catalyst, the quality ratio of added hydrochloric acid and material I was 0.5:1.Toluene and acetone are found successfully to replace benzene, and the quality ratio of added toluene and acetone and material I was 2.5:2.5:1.We improved to achieve green synthesis, and increased yield.