Description

S-(tert-Butylthio)-L-Cysteine Hydrate is a specialized, protected derivative of the amino acid L-cysteine. This compound is of significant value in pharmaceutical research and development, primarily serving as a key chiral building block and a reagent for introducing sulfur-containing functional groups. It is essential for scientists and manufacturers in the pharmaceutical, biotechnology, and fine chemical synthesis sectors who require high-purity intermediates for peptide synthesis and the development of novel active pharmaceutical ingredients (APIs).

Application

• Pharmaceutical Intermediate: A critical chiral building block in the synthesis of complex drug candidates and active pharmaceutical ingredients (APIs).
• Peptide Synthesis: Used in solid-phase and solution-phase peptide chemistry to incorporate a protected cysteine residue with a tert-butylthio (S-tBu) protecting group.
• Bioconjugation & Protein Engineering: Serves as a reagent for site-specific modification of proteins and antibodies, enabling the creation of antibody-drug conjugates (ADCs) and other bioconjugates.
• Chemical Biology Research: Employed as a tool compound to study enzyme mechanisms, protein folding, and redox biology involving thiol groups.
• Catalyst & Ligand Preparation: Used in the preparation of chiral ligands and catalysts for asymmetric synthesis.
• Reference Standard: Serves as a high-purity analytical standard for quality control and method development in pharmaceutical laboratories.

Basic Information

Product Name	S-(tert-Butylthio)-L-Cysteine Hydrate
CAS No.	313223-16-4
Molecular Formula	C7H15NO2S2 • xH2O
Molecular Weight	209.33 (Anhydrous basis)
Synonyms	L-Cysteine, S-(1,1-dimethylethyl)thio-, hydrate; S-tert-Butylthio-L-cysteine hydrate; (R)-2-Amino-3-((tert-butylthio)thio)propanoic acid hydrate; S-t-Butylthio-L-cysteine hydrate; S-(tert-Butylmercapto)-L-cysteine hydrate; NSC 339586 hydrate; Protected L-cysteine derivative; Cysteine S-tBu ether hydrate
EINECS	Contact for details

Quality Control

Our S-(tert-Butylthio)-L-Cysteine Hydrate is manufactured under strict quality management systems. Each batch undergoes comprehensive analytical testing, including chiral purity verification by HPLC, to ensure it meets the stringent requirements for pharmaceutical R&D and cGMP applications. A detailed Certificate of Analysis (COA) providing specifications for identity, assay, chiral purity, and related substances is provided with every shipment.

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 must be kept under anhydrous conditions. For long-term storage, consider storing under an inert atmosphere such as nitrogen or argon.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 98.0% (anhydrous basis)
Chiral Purity (HPLC)	≥ 99.0% (L-isomer)
Water Content (KF)	≤ 2.0%
Residue on Ignition	≤ 0.1%
Heavy Metals	≤ 10 ppm

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