Description

(4R)-1-Boc-4-Methylthiol-L-Proline Methyl Ester CAS NO 1252640-75-7 is a high-purity, non-natural amino acid derivative featuring a Boc-protected amine and a thioether side chain. This compound is a critical chiral building block in the synthesis of complex bioactive molecules, particularly in pharmaceutical research and development. It is primarily utilized by medicinal chemists and process development scientists in the pharmaceutical and biotechnology industries for constructing peptide mimetics and novel drug candidates.

Application

• Pharmaceutical Intermediate: A key chiral synthon for the synthesis of protease inhibitors and other therapeutic peptides.
• Peptidomimetic Research: Used to introduce constrained proline analogs and thioether functionalities into peptide backbones to enhance metabolic stability and bioavailability.
• Drug Discovery: Serves as a versatile building block in combinatorial chemistry and library synthesis for high-throughput screening.
• Chemical Biology Probes: Employed in the development of activity-based probes and labeled compounds for studying enzyme mechanisms.
• Process Chemistry: Used in the scale-up and optimization of synthetic routes for active pharmaceutical ingredients (APIs).

Basic Information

Product Name	(4R)-1-Boc-4-Methylthiol-L-Proline Methyl Ester
CAS No.	1252640-75-7
Molecular Formula	C12H21NO4S
Molecular Weight	275.36 g/mol
Synonyms	1-Boc-4-(methylthio)-L-proline methyl ester; (4R)-1-(tert-Butoxycarbonyl)-4-(methylthio)-L-proline methyl ester; Methyl (4R)-1-[(2-methylpropan-2-yl)oxycarbonyl]-4-(methylsulfanyl)pyrrolidine-2-carboxylate; Boc-4-(MeS)-L-Pro-OMe; (4R)-4-(Methylthio)-1-[(tert-butoxy)carbonyl]pyrrolidine-2-carboxylic acid methyl ester; tert-Butyl (4R)-4-(methylthio)-2-(methoxycarbonyl)pyrrolidine-1-carboxylate
EINECS	Contact for details

Quality Control

Our (4R)-1-Boc-4-Methylthiol-L-Proline Methyl Ester is manufactured under strict quality management systems. Each batch undergoes comprehensive analytical testing, including HPLC for purity, chiral analysis for enantiomeric excess, and NMR for structural confirmation, to ensure it meets the stringent requirements for pharmaceutical R&D. Certificates of Analysis (COA) with full traceability are provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at 2-8°C or as indicated on the label. This material is hygroscopic (moisture-sensitive) and should be handled under an inert atmosphere or in a controlled, dry environment to maintain stability and purity.

Specification

Item	Specification
Appearance	White to off-white solid
Identification (IR)	Conforms to structure
Identification (HPLC)	Conforms to reference
Assay (HPLC)	≥98.0%
Chiral Purity (HPLC)	≥99.0% ee
Water Content (KF)	≤0.5%
Residue on Ignition	≤0.1%

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