3,5-Dichloro-L-Phenylalanine

3,5-Dichloro-L-Phenylalanine is a halogenated, proteinogenic amino acid derivative in which the phenylalanine aromatic side chain bears two chlorine substituents at the 3- and 5-positions, with the amino acid backbone retaining the L-configuration indicated in the name. The molecule contains a free α-amino group and a free α-carboxyl group, and its dichloro-substituted benzyl side chain provides increased hydrophobicity and altered electronic properties relative to unsubstituted phenylalanine while remaining compatible with peptide bond formation as an amino acid building block. In synthetic peptide chemistry and chemical biology, it is used to introduce a chlorinated aromatic residue for structure-activity studies, conformational or binding investigations, and the preparation of modified peptides and protein analogues for analytical characterization.

Designed for biological research and industrial applications, not intended for individual clinical or medical purposes.

CAT No: CP12501

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M.W/Mr.
234.08

3,5-Dichloro-L-Phenylalanine is a halogenated L-phenylalanine building block featuring two chlorine substituents on the aromatic ring, which strongly influences electronic properties and hydrophobic character while preserving the amino acid backbone for downstream derivatization. This non-proteinogenic amino acid is commonly used in peptide and peptidomimetic research where aromatic substitution patterns are used to probe structure-activity relationships, tune physicochemical behavior, and introduce steric/electronic effects at a defined position. Its stereodefined L-configuration also supports consistent incorporation into synthetic peptide sequences and related medicinal chemistry intermediates.

1. Peptidomimetic Building Block

3,5-Dichloro-L-Phenylalanine is used by medicinal chemistry and peptide chemistry groups to construct peptidomimetics and substituted peptide analogs that incorporate a halogenated aromatic side chain at a defined residue position. The dichloro substitution provides a practical handle for studying how ring electronics and hydrophobicity affect conformation, receptor/target engagement, and overall lead optimization during structure-activity relationship campaigns. Researchers frequently select this amino acid when they need a non-natural aromatic variant that remains compatible with standard amino acid coupling workflows and supports systematic comparison against other substituted phenylalanine analogs.

2. Protein Labeling Probes

3,5-Dichloro-L-Phenylalanine is also applied in chemical biology workflows that require an unnatural aromatic amino acid for residue-level labeling strategies, particularly when halogenated phenylalanine analogs are used to introduce a distinct chemical motif into peptides or proteins for subsequent detection or enrichment. In practice, it serves as a defined building block for preparing labeled peptide standards and probe materials used in binding studies, proteomics sample preparation optimization, and method development where a distinguishable aromatic signature is advantageous. The presence of two chlorine atoms helps differentiate the labeled material in analytical workflows such as LC-MS by providing a characteristic mass pattern and improved chromatographic behavior relative to unsubstituted phenylalanine derivatives.

3. Pharmaceutical Intermediate Synthesis

3,5-Dichloro-L-Phenylalanine is used as a pharmaceutical intermediate building block for preparing halogenated aromatic fragments that appear in small-molecule and peptide-derived drug candidates. Process and R&D chemists rely on its amino acid functionality as a controlled starting point for generating substituted aromatic intermediates, including derivatives used in medicinal chemistry libraries and route scouting. The dichloro pattern is particularly valuable when a development team needs to preserve a specific substitution pattern through multiple downstream transformations while maintaining stereochemical integrity of the amino acid-derived scaffold for late-stage assembly steps.

4. Analytical Reference Standards

3,5-Dichloro-L-Phenylalanine is frequently employed as an analytical reference material for LC-MS method development and quantitative workflows involving halogenated amino acid derivatives. Laboratories use it to verify retention time and fragmentation behavior of substituted phenylalanine species, to calibrate or qualify analytical runs, and to support identification of dichloro-substituted aromatic residues in peptide mixtures. Because the molecule contains two chlorine atoms, it provides a robust mass signature that is useful for confirming selectivity of detection in complex matrices encountered during peptide synthesis monitoring, degradation studies, and analytical method validation.

Abbr
H-Phe(3,5-Cl2)-OH

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