Amoxicillin sodium

26787-78-0

34642-77-8

Synthesis of (2S,5R,6R)-6-((R)-2-amino-2-(4-hydroxyphenyl)acetamido)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid as sodium salt. 7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid in the following general steps: Example 1: Preparation of sterile sodium amoxicillin using methyl acetate as solvent. The specific operations were as follows: 1. amoxicillin trihydrate (50 g) was dissolved in a solvent mixture of methyl acetate (92 mL), triethylamine (34 g) and methanol (52 mL). 2. The reaction mixture was stirred continuously at a temperature of 0-5°C until a clarified solution was formed, followed by filtration through a sterile filtration system. 3. sodium 2-ethylhexanoate (34 g) was dissolved in a solvent mixture of methyl acetate (92 mL) and methanol (52 mL) and filtered through a sterile filtration system. 4. The sodium 2-ethylhexanoate solution prepared in Step 3 was slowly added to the amoxicillin trihydrate solution from Step 2, maintaining the reaction temperature between 0-5°C. 5. After 80 minutes of reaction, methyl acetate (10 mL) was added to promote precipitation of the product. 6. The precipitate was collected by filtration, washed with methyl acetate (240 mL) and dried at a temperature lower than 50 °C, resulting in sterile sodium amoxicillin. Product yield was >90%.