5-Cl-ICA-OEt is an amino acid ester derivative featuring a chlorinated indole-containing side chain (5-chloro substituted) connected to an amino acid core and capped as the ethyl ester (OEt), placing it in the class of non-proteinogenic, structurally modified amino acid esters used for chemical synthesis and labeling workflows. The molecule contains an esterified carboxyl group and a free amino functionality (as indicated by the "ICA" core naming), with the 5-chloro substituent providing a defined halogenated aromatic handle that can influence reactivity and analytical behavior. In research and synthesis, such amino acid ester forms are employed as protected/activated carboxyl equivalents for stepwise assembly of more complex amino acid and peptide derivatives, as well as substrates or building blocks in structure-activity studies and analytical method development where the halogenated indole motif and ester stability are relevant.
CAT No: CP25858
CAS No:4792-67-0
Synonyms/Alias:4792-67-0;Ethyl5-chloro-1H-indole-2-carboxylate;Ethyl5-chloroindole-2-carboxylate;Ethyl5-chloro-2-indolecarboxylate;5-Chloroindole-2-carboxylicAcidEthylEster;ETHYL-5-CHLOROINDOLE-2-CARBOXYLATE;LWKIFKYHCJAIAB-UHFFFAOYSA-N;5-chloro-2-IndolecarboxylicAcidEthylEster;5-chloro-1H-indole-2-carboxylicacidethylester;1H-Indole-2-carboxylicacid,5-chloro-,ethylester;NSC94209;PubChem7173;ACMC-1AOIF;AC1L2VEJ;AC1Q3MRQ;SCHEMBL42366;KSC494S4P;138096_ALDRICH;IND030;CTK3J4947;LWKIFKYHCJAIAB-UHFFFAOYSA-;ZINC56441;MolPort-000-147-488;BB_SC-9377;2-CARBETHOXY-5-CHLOROINDOLE
Chemical Name:5-Chloroindole-2-carboxylic acid ethyl ester, 98%
5-Cl-ICA-OEt is an ethyl ester derivative of a chlorinated indole-3-carboxylic acid scaffold, providing an activated carboxylate for downstream organic synthesis and derivatization workflows. The presence of the ester functionality supports controlled reactivity during intermediate preparation, while the 5-chloro substitution and indole core make it a useful platform for building substituted heteroaryl carboxylate derivatives used in chemical biology and medicinal chemistry programs. Researchers typically handle this compound as a synthetic intermediate rather than a proteinogenic amino acid, leveraging its defined aromatic substitution pattern to access structure-defined analog series.
1. Pharmaceutical Intermediate Synthesis
5-Cl-ICA-OEt is used as a heteroaryl carboxylate intermediate in medicinal chemistry and small-molecule discovery chemistry, where the indole-3-carboxylate motif is a common starting point for analog development. Teams developing substituted indole carboxylic acid derivatives rely on the ethyl ester form to enable stepwise functional group manipulation before converting to the corresponding acid or alternative activated derivatives for further coupling chemistry. The defined 5-chloro substitution supports consistent SAR (structure-activity relationship) exploration across series, particularly when downstream targets require a fixed halogen pattern on the indole ring.
2. Heteroaryl Ester Derivatization
5-Cl-ICA-OEt is frequently selected for preparing a range of indole-3-carboxylate derivatives through ester-to-derivative transformations used in synthetic libraries. Synthetic chemistry groups use the ester functionality as a handle for controlled downstream conversion to alternative carboxylate forms (for example, acid, amide, or other activated carboxyl derivatives) depending on the coupling strategy required by the target scaffold. The aromatic indole core and the 5-chloro substituent help maintain structural integrity during derivatization, supporting the generation of well-defined substituted heteroaryl building blocks for screening collections and reference material preparation.
3. SAR Analog Library Building
5-Cl-ICA-OEt supports analog library construction in hit-to-lead and lead-optimization workflows by providing a structurally constrained starting point with a chlorinated indole framework. Medicinal chemistry researchers use this type of intermediate to rapidly generate series of closely related compounds that differ at the carboxylate-derived substitution level, enabling systematic evaluation of how carboxylate functionality influences physicochemical properties and structure-activity trends. Because the compound is already an ester, it fits common library workflows that require standardized intermediate handling prior to final functional group installation.
4. Chemical Biology Probe Precursors
5-Cl-ICA-OEt can serve as a precursor for chemical biology reagent development when an indole-3-carboxylate motif is used as a recognition or scaffold element in probe design. Researchers preparing tagged or derivatized indole carboxylate probes often begin from ester intermediates to manage reactivity and compatibility with subsequent functional group installation steps (such as conversion to coupling-ready carboxyl derivatives). The 5-chloro substitution provides an additional handle for tuning scaffold electronics and maintaining a defined substitution pattern across probe analogs used in binding studies, enrichment experiments, or mechanistic chemical biology tool development.
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