阿莫西林杂质L的化学合成

阿莫西林是一种最常用的β-内酰胺抗生素,作为基本医疗系统中最重要药物之一被世界卫生组织基本药物标准清单收录。其杂质L,即:(2S,5R,6R)-6-((2S,5R,6R)-6-((R)-2-氨基-2-(4-羟基苯基)乙酰氨基)-3,3-二甲基-7-氧代-4-硫杂-1-氮杂双环[3.2.0]庚烷-2-甲酰胺)-3,3-二甲基-7-氧代-4-硫杂-1-氮杂双环[3.2.0]庚烷-2-甲酸(6-APA amoxicillin amide),由于含量少难以获取成为影响产品质量的因素之一,因此,我们以6-氨基青霉素烷酸和阿莫西林三水合物为原料,分别通过3步和1步转化为相应的中间体化合物3和6,并使用酰胺缩合试剂六氟磷酸苯并三唑-1-基-氧基三吡咯烷基磷(PyBOP)以76%的收率实现了化合物3和6的脱水缩合,得到的关键中间体化合物7在Pd/C催化条件下一步脱除苄基及两个苄氧羰基保护基,首次通过化学方法合成了β-内酰胺化合物阿莫西林杂质L,反应使用简单易得的原料,温和的反应条件,无需复杂的分离纯化处理,对以阿莫西林为代表的β-内酰胺类抗生素的过敏研究以及新型β-内酰胺抗生素的开发和作用机制研究等有着参考和借鉴意义。

Synthesis of Amoxicillin Inpurity L

Amoxicillin is a β-lactam antibiotic used for the treatment of a number of bacterial infections. It is on the World Health Organization's List of Essential Medicines, and one of the most important medications needed in a basic health system. The insufficient sources of its impurity L, i.e., (2S,5R,6R)-6-((2S,5R,6R)-6-((R)-2-amino-2-(4-hydroxyphenyl)acetamido)-3,3-dime-thyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxamido)-3,3-dimethyl-7-oxo-4-thia-1-azabicy-clo[3.2.0]heptane-2-carboxylic acid(6-APA amoxicilin amide), affect the quality control of the product. Herein, the first synthesis of amoxicillin impurity L, was reported by using a simple and efficient method. The starting materials of 6-aminopenicilanic acid and amoxycillin trihydrate were converted to intermediate compounds 3 and 6 through three-step and one-step reactions, respectively. By using benzotriazole-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate(PyBOP) as peptide coupling reagent, we successfully synthesized key intermediate 7 from compounds 3 and 6 in 76% yield, which was subsequently transformed to 6-APA amoxicillin amide by fully deprotection of benzyl and two carbobenzyloxy(Cbz) protecting groups. This method not only increases the source of the standard substance for quality control of amoxicillin, but also provides inspiration for novel β-lactam antibiotic and antiallergic research.