Description

Cysteine,S-Methyl-, Ethyl Ester, Hydrochloride (9Ci) is a protected cysteine derivative, specifically the S-methyl ethyl ester hydrochloride salt. This compound is a crucial building block in peptide synthesis and pharmaceutical research, offering enhanced stability and solubility for complex chemical transformations. It is primarily needed by research institutions, pharmaceutical development labs, and fine chemical manufacturers engaged in the production of bioactive peptides, drug candidates, and specialized amino acid analogs.

Application

• Peptide Synthesis Intermediate: A key protected amino acid derivative for the solid-phase and solution-phase synthesis of complex peptides and proteins.
• Pharmaceutical Research & Development: Serves as a critical building block in the discovery and development of new drug candidates, particularly those targeting enzyme inhibition or protein-protein interactions.
• Biochemical Research: Used in studies of protein structure, function, and folding, as well as in the preparation of enzyme substrates and inhibitors.
• Fine Chemical Manufacturing: An intermediate in the production of specialized amino acid derivatives, chiral auxiliaries, and other high-value synthetic targets.
• Protecting Group Strategy: The S-methyl and ethyl ester groups provide orthogonal protection for the thiol and carboxylic acid functionalities, respectively, enabling selective deprotection during multi-step syntheses.

Basic Information

Product Name	Cysteine,S-Methyl-, Ethyl Ester, Hydrochloride (9Ci)
CAS No.	61786-58-1
Molecular Formula	C6H13NO2S • HCl
Molecular Weight	199.70 g/mol
Synonyms	S-Methyl-L-cysteine ethyl ester hydrochloride; Ethyl S-methyl-L-cysteinate hydrochloride; L-Cysteine, S-methyl-, ethyl ester, hydrochloride; S-Methylcysteine ethyl ester HCl; (2R)-2-Amino-3-(methylsulfanyl)propanoic acid ethyl ester hydrochloride; NSC 334365; Amino acid derivative C6H13NO2S•HCl
EINECS	Contact for details

Quality Control

Our Cysteine,S-Methyl-, Ethyl Ester, Hydrochloride is produced under strict quality management systems. Each batch undergoes rigorous analytical testing to ensure identity, purity, and consistency. We provide comprehensive Certificates of Analysis (COA) with each shipment, detailing key parameters such as assay, chiral purity, and impurity profiles. Our quality commitment supports applications in research and cGMP-compliant environments.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at controlled room temperature (15-25°C). This product is hygroscopic (moisture-sensitive) and must be kept under anhydrous conditions. For long-term storage, consider storing under an inert atmosphere.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥98.0%
Optical Rotation	Contact for details
Chiral Purity (HPLC)	≥99.0% ee
Water Content (KF)	≤1.0%
Residue on Ignition	≤0.1%
Heavy Metals	≤20 ppm

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