Top 10 Manufacturers of Pharmaceutical Intermediate CAS No. 90357-53-2 in 2025

Understanding (2R,3S)-3-Phenylisoserine Methyl Ester Hydrochloride (CAS No. 90357-53-2)

CAS No. 90357-53-2, known as (2R,3S)-3-Phenylisoserine methyl ester hydrochloride, is a highly specialized chiral intermediate used in the synthesis of Docetaxel (Taxotere)—a leading anti-cancer medication used in the treatment of breast cancer, non-small cell lung cancer, prostate cancer, and other solid tumors.

This compound represents the esterified and salt-formed version of 3-phenylisoserine, making it more soluble and reactive in key coupling steps during taxane production. The (2R,3S) configuration ensures the pharmacologically active stereochemistry required for effective microtubule inhibition in cancer cells.

Importance of CAS No. 90357**-53-2 in Pharmaceutical Manufacturing**

Core Intermediate in Docetaxel Synthesis

As part of the Docetaxel side chain, this intermediate plays a central role in assembling the final cytotoxic compound with optimal activity.

Improved Reactivity for Coupling Reactions

The methyl ester form facilitates downstream esterification steps, while the hydrochloride salt enhances solubility and stability.

Strict Stereochemical Requirements

Only the (2R,3S) enantiomer is used in API synthesis due to its alignment with receptor binding and therapeutic effect.

Optimized for Semi-Synthetic Processes

Used in taxane semi-synthesis from natural precursors such as 10-DAB (10-deacetylbaccatin III), it enables high-yield API production.

Demand from CDMOs and Oncology Pipelines

This intermediate is in consistent demand from contract manufacturers and pharmaceutical companies working on cancer therapeutics.

Top 10 Manufacturers of CAS No. 90357-53-2

1. Lonza Group

• Location: Basel, Switzerland

• Overview: Lonza delivers high-purity chiral intermediates under GMP, including taxane building blocks like CAS 90357-53-2 for oncology APIs.

• Specialty: Scalable and compliant synthesis of cytotoxic intermediates.

2. Bachem AG

• Location: Bubendorf, Switzerland

• Overview: Bachem specializes in the production of stereochemically defined amino acid derivatives and oncology intermediates.

• Specialty: Advanced peptide and esterified intermediates with salt forms.

3. Eastfine

• Location: Changzhou City, Jiangsu Province, China

• Overview: Eastfine supplies CAS No. 90357-53-2 with high enantiomeric purity, strong batch consistency, and full regulatory documentation for global export.

• Specialty: Oncology-grade intermediates for semi-synthetic APIs like Docetaxel.

4. CordenPharma

• Location: Plankstadt, Germany

• Overview: CordenPharma produces high-potency intermediates and GMP-compliant taxane side chains for clinical and commercial supply.

• Specialty: Oncology-focused CDMO with full route development.

5. Almac Group

• Location: Craigavon, Northern Ireland

• Overview: Almac offers cGMP synthesis of esterified and protected intermediates for cancer drug development and commercial manufacturing.

• Specialty: Route optimization for small- to mid-volume oncology intermediates.

6. Olon S.p.A.

• Location: Milan, Italy

• Overview: Olon supports taxane production with tailored building blocks like CAS 90357-53-2, manufactured in EU GMP-certified facilities.

• Specialty: Consistent intermediate supply for injectable oncology APIs.

7. Pharmaron UK

• Location: Hoddesdon, United Kingdom

• Overview: Pharmaron’s UK operations offer contract synthesis of taxane-related intermediates for early- and late-stage development.

• Specialty: Flexible manufacturing with emphasis on purity and speed.

8. Carbogen Amcis

• Location: Bubendorf, Switzerland

• Overview: Carbogen Amcis delivers custom synthesis of cytotoxic intermediates, including esterified chiral acids and their salts.

• Specialty: Contained GMP manufacturing of highly potent intermediates.

9. Enzymaster Life Sciences

• Location: Düsseldorf, Germany

• Overview: Enzymaster uses enzyme-driven processes to produce optically pure chiral intermediates like 90357-53-2 with excellent yield and sustainability.

• Specialty: Biocatalytic routes for green and scalable chiral synthesis.

10. Seqens Group

• Location: Ecully, France

• Overview: Seqens produces Docetaxel intermediates under GMP, with capabilities in crystallization, salt formation, and analytical validation.

• Specialty: Custom manufacturing for oncology intermediates in Europe.

Trends in the Pharmaceutical Intermediates Market

Taxane API Expansion

Docetaxel remains a frontline treatment for multiple cancers. Intermediate demand continues as new generic and combination formulations emerge globally.

Salt Form Optimization

Intermediates like CAS 90357-53-2 are increasingly preferred in hydrochloride salt form for better stability and solubility during synthesis and transport.

Chiral Synthesis Innovation

New asymmetric synthesis and enzymatic methods are improving yield and reducing waste in taxane intermediate manufacturing.

Focus on Quality and Regulatory Support

Oncology intermediates face strict scrutiny from the FDA, EMA, and PMDA, requiring detailed impurity profiling and consistent quality control.

Outsourcing of Specialized Synthesis

Many pharmaceutical companies are outsourcing the production of intermediates to experienced CDMOs to save time and ensure regulatory compliance.

Conclusion

CAS No. 90357-53-2, or (2R,3S)-3-Phenylisoserine Methyl Ester Hydrochloride, is a highly valuable intermediate in the synthesis of Docetaxel, a globally used cancer treatment. With its Boc-protected ester form and high chiral purity, it supports efficient and reliable oncology drug production.

Manufacturers like Lonza, Bachem, Eastfine, and others continue to play a key role in ensuring the pharmaceutical industry’s access to this critical building block under rigorous international standards.