Description

S-tert-Butylmercapto-L-Cysteine is a specialized, sulfur-containing derivative of the amino acid L-cysteine. This compound is a valuable chiral building block and protective agent in advanced organic synthesis, particularly for the pharmaceutical industry. Its primary value lies in its ability to introduce the tert-butylthio (S-t-Bu) protecting group, which is stable under a wide range of reaction conditions yet can be selectively removed. Key industries that utilize this chemical include pharmaceutical R&D and manufacturing, where it is essential for the synthesis of peptides, complex drug intermediates, and other bioactive molecules.

Application

• Pharmaceutical Intermediate: A critical chiral synthon in the synthesis of active pharmaceutical ingredients (APIs), especially those containing modified cysteine residues.
• Peptide Synthesis: Used as a protected cysteine derivative in solid-phase and solution-phase peptide synthesis to prevent unwanted disulfide bond formation during assembly.
• Protecting Group Chemistry: Serves as a source of the S-tert-butyl (S-t-Bu) protecting group for thiols in multi-step organic syntheses.
• Bioconjugation & Protein Engineering: Facilitates site-specific modifications of proteins and antibodies by providing a handle for thiol-based coupling reactions.
• Research & Development: Employed in academic and industrial R&D labs for exploring new synthetic methodologies and developing novel therapeutic compounds.
• Precursor for Chelating Agents: Can be used in the development of specialized ligands and chelating agents due to its sulfur and nitrogen donor atoms.

Basic Information

Product Name	S-tert-Butylmercapto-L-Cysteine
CAS No.	30044-51-0
Molecular Formula	C7H15NO2S2
Molecular Weight	209.33 g/mol
Synonyms	L-Cysteine, S-(1,1-dimethylethyl)thio-; (R)-2-Amino-3-((tert-butylthio)thio)propanoic acid; S-tert-Butylthio-L-cysteine; tert-Butyl L-cysteinate sulfide; S-t-Butylmercaptocysteine; NSC 334365; 2-Amino-3-(tert-butylsulfanyl)thiopropanoic acid
EINECS	Contact for details

Quality Control

Our S-tert-Butylmercapto-L-Cysteine is manufactured under strict quality management systems. Each batch undergoes rigorous analytical testing to ensure high chemical purity, correct stereochemistry, and batch-to-batch consistency. We provide comprehensive Certificates of Analysis (COA) with each shipment, detailing key parameters such as assay, enantiomeric purity, and impurity profiles. Our quality commitment aligns with cGMP principles for pharmaceutical-grade intermediates, ensuring reliability for critical synthesis applications.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated place at a controlled room temperature (15-25°C). This product is hygroscopic (moisture-sensitive) and should be handled in a dry environment to prevent degradation. Keep away from strong oxidizing agents.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 98.0%
Optical Rotation [α]	Contact for details
Loss on Drying	≤ 1.0%
Heavy Metals	≤ 20 ppm
Residue on Ignition	≤ 0.1%
Related Substances (HPLC)	Individual impurity ≤ 0.5%; Total impurities ≤ 2.0%

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