Description

L-Cysteine, 2-Methyl-, Ethyl Ester (9Ci) is a specialized, high-purity derivative of the amino acid cysteine, designed for advanced research and synthesis applications. This compound is valued for its role as a key chiral building block and protecting group in the synthesis of complex peptides and pharmaceutical intermediates. It is primarily utilized by researchers and manufacturers in the pharmaceutical, biotechnology, and fine chemical sectors for developing novel therapeutic agents and biochemical tools.

Application

• Pharmaceutical Intermediate: A critical chiral synthon for the synthesis of novel peptide-based drugs and active pharmaceutical ingredients (APIs).
• Biochemical Research: Used in proteomics and enzymology studies as a substrate analog or a reagent for protein modification.
• Peptide Synthesis: Serves as a protected cysteine derivative in solid-phase and solution-phase peptide synthesis to prevent unwanted side reactions.
• Fine Chemical Production: Employed in the manufacture of specialized catalysts, ligands, and other high-value fine chemicals.
• Reference Standard: Used as an analytical standard in quality control laboratories for method development and validation.

Basic Information

Product Name	L-Cysteine, 2-Methyl-, Ethyl Ester (9Ci)
CAS No.	158785-71-8
Molecular Formula	C6H13NO2S
Molecular Weight	163.24 g/mol
Synonyms	L-2-Methylcysteine Ethyl Ester; Ethyl (2R)-2-Amino-3-mercapto-2-methylpropanoate; (R)-2-Amino-3-mercapto-2-methylpropionic Acid Ethyl Ester; 2-Methyl-L-cysteine Ethyl Ester; NSC 332008; L-β-Methylcysteine Ethyl Ester; Ethyl L-2-Methylcysteinate
EINECS	Contact for details

Quality Control

Our L-Cysteine, 2-Methyl-, Ethyl Ester (9Ci) is manufactured under strict quality management systems. Each batch undergoes comprehensive analytical testing, including chiral purity verification and impurity profiling, to ensure it meets the stringent requirements for research and synthesis. A detailed Certificate of Analysis (COA) is provided with every shipment, confirming identity, purity, and compliance with relevant specifications.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). This material is hygroscopic (moisture-sensitive) and should be handled in a dry environment to prevent degradation. For long-term storage, consider using desiccants.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 98.0%
Chiral Purity (HPLC)	≥ 99.0% ee
Loss on Drying	≤ 1.0%
Residue on Ignition	≤ 0.1%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.