AE-Active Ester (Chinese name: AE-活性酯) is one of the most important side-chain intermediates in the production of semi-synthetic cephalosporin antibiotics. Chemically, it is the S-benzothiazol-2-yl thioester of 2-methoxyimino-2-(2-aminothiazol-4-yl)acetic acid, which reacts with 7-aminocephalosporanic acid (7-ACA) under coupling conditions to form the active side chain of third- and fourth-generation cephalosporins.
Thanks to its methoxyimino group and activated thioester moiety, AE-Active Ester offers excellent reactivity and regioselectivity in side-chain condensation, helping manufacturers achieve high coupling yields while keeping related-substance levels low. It is a foundational raw material for a wide range of clinically essential antibiotics and is produced at scale by leading API suppliers in China.
Chemical Properties
Chemical & Pharmaceutical Properties
AE-Active Ester Structural Formula
Specification Parameters
Each batch of AE-Active Ester is released against a comprehensive in-house specification covering purity, key related substances, clarity, and color metrics. Typical release limits are as follows:
| Test Item | Specification |
|---|---|
| Purity | ≥ 99.00% |
| Aminothiazole Oxime Acid | ≤ 0.20% |
| AE-Active Ester trans-Isomer | ≤ 0.20% |
| Dibenzothiazyl Disulfide (DM) | ≤ 0.30% |
| Free Aminothiazole Oxime Acid | ≤ 0.20% |
| Clarity | ≤ No. 1 |
| Turbidity | ≤ 6.0 NTU |
| Absorbance (A425) | ≤ 0.580 |
| Absorbance (A450) | ≤ 0.150 |
| Loss on Drying | ≤ 0.20% |
Packaging
In-Stock Supply Available
Application Fields
- Core cephalosporin side chain: One of the most important side-chain intermediates for semi-synthetic cephalosporin antibiotics, coupling with the 7-ACA nucleus to form the active molecule.
- Third-/fourth-generation APIs: Key intermediate for synthesizing cefotaxime sodium, ceftriaxone sodium, cefpirome, and cefepime — widely used third- and fourth-generation semi-synthetic cephalosporins.
- Main antibiotic raw material: A primary raw material for producing ceftriaxone (头孢三嗪), cefotaxime sodium, and other essential anti-infective pharmaceutical products.
For detailed technical documentation, COA, or to discuss bulk supply and custom specifications of AE-Active Ester, please contact our technical team. Taikomed maintains stable inventory and provides one-stop technical service from intermediate supply to process support.