摘要
本文在制得青霉素 G亚砜的基础上 ,完成了重排酸的扩环反应 ,重点探讨了扩环反应的最优化条件。青霉素 G亚砜与 N,N′-双 (三甲基甲硅基 )脲 (BSU)在 5 5℃下反应 ,得到亚砜的酯化物。加入催化剂吡啶乙酰溴 ,回流条件下发生扩环反应。最后加水脱去酯基 ,加酸析出产物重排酸。通过正交实验可得出以下结论 :当 N,N′-双 (三甲基甲硅基 )脲 -亚砜为 2 .5 :1,乙酰溴 -亚砜为 0 .4:1,吡啶 -乙酰溴为 1.5 :1,回流时间为 3.5 h,酸化 p H值为 1.8时 ,扩环反应结果最好 ,总收率可达 76 % ,纯度 97%以上。
In the present paper, the synthetic process of rearranging acid from penicillin G sulphoxide is investigated and synthetic conditions are determined. Penicillin G sulphoxide is esterified by N,N′ bistrimethylsilyl urea (BSU) under the temperature 55℃ with a molar ratio 2.5∶1 between BSU and sulphoxide, and the ester obtained is ring enlarged in the toluene under refluxing with the exist of catalyst pyridine acetyl bromide. Then the product is hydrolyzed to remove the protecting group and precipitated by addition of dilute sulfic acid. It is found that when the molar ratio of sulphoxide, pyridine and acetyl bromide is 1∶0.6∶0.4, the catalytic effect on the ring enlargment is the best, and the yield and purity of the final product can reach 76% and 97% respectively at a pH of 1.8 in toluene under refluxing for about 3.5h.
出处
《中国抗生素杂志》
CSCD
北大核心
2000年第3期178-180,共3页
Chinese Journal of Antibiotics
关键词
7-ADCA
7-苯乙酰氨基脱乙酰氧基头孢烷酸
合成
phenylacetamido desacetoxycephalosporanic acid
Pyridine acetyl bromide
N
N' bistrimethylsilyl urea (BSU)
Purification
