摘要
以右旋糖酐和乙酰水杨酰氯为原料,合成了高分子偶联物右旋糖酐 阿司匹林,并用FTIR、1HNMR对其结构进行了表征。考察了缚酸剂、右旋糖酐重均相对分子质量、反应温度和物料比对酯化反应的影响。结果表明,三乙胺和吡啶均可作为该酯化反应的缚酸剂,而浓氢氧化钠水溶液则不适合;乙酰水杨酰基的接入率随右旋糖酐重均相对分子质量的增大而减小,但随乙酰水杨酰氯与右旋糖酐的质量比的增加而增大;当选用Mw=20 000的右旋糖酐、缚酸剂三乙胺,反应温度在 60℃左右、m(乙酰水杨酰氯) /m(右旋糖酐 ) =3. 06时,乙酰水杨酰基的接入率和其有效转化率分别为 9. 30%和 3 .07%。
In order to obtain a sustained release aspirin derivative having less side-effect on gastrointestinal tract,dextran-aspirin conjugate was prepared by coupling reaction between o-acetoxybenzoyl chloride and dextran.Its structure was characterized with FTIR and ~1HNMR.Influences of various factors,such as acid absorbent,molecular weight of dextran,reaction temperature and mass ratio of reactants,on this reaction were investigated.UV spectrum was applied to evaluate the drug-loading ratio of dextran-aspirin conjugate produced under different reaction conditions.The results show that both triethylamine and pyridine are effective acid absorbents in this reaction,while sodium hydroxide solution could not be used as acid absorbent.The drug-loading ratio of dextran-aspirin conjugate decreases with increase in average molecular weight of dextran,while increases with increase in mass ratio of o-acetoxybenzoyl chloride to dextran.Thus,reaction of o-acetoxybenzoyl chloride and dextran having average molecular weight of 20,000 in mass ratio of 3.06 was carried out at 60 ℃,using dimethyl sulphoxide as solvent and triethylamine as acid absorbent.Under these optimum reaction conditions,the drug-loading ratio about 9.30% and the converting efficency about 3.07% were attained.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2005年第3期205-208,共4页
Fine Chemicals