Ethyl 3-(2-chloroacetamido)benzoate: Properties & Applications
Ethyl 3-(2-chloroacetamido)benzoate: Properties & Applications
Ethyl 3-(2-chloroacetamido)benzoate is a bifunctional organic intermediate combining a reactive chloroacetamide electrophile with an ester-bearing aromatic scaffold, making it a versatile building block for medicinal chemistry and targeted organic synthesis.
- Chemical Name
- Ethyl 3-(2-chloroacetamido)benzoate
- SKU
- E697608
- Molecular Formula
- C₁₁H₁₂ClNO₃
- Molecular Weight
- 241.67 g/mol
- Key Functional Groups
- Chloroacetamide, aromatic amine (secondary amide), ethyl ester
- Primary Application
- Electrophilic building block in organic and medicinal chemistry synthesis
- Supplier
- Aladdin Scientific
Chemical Structure and Physicochemical Properties
Ethyl 3-(2-chloroacetamido)benzoate (molecular formula C₁₁H₁₂ClNO₃; MW approximately 241.67 g/mol) is an aromatic compound featuring three distinct functional elements: an ethyl ester group, a meta-positioned secondary amide linkage, and a chloromethyl carbonyl (chloroacetyl) moiety. The compound belongs to the chloroacetamide class of reactive intermediates, where the carbon–chlorine bond adjacent to the carbonyl provides significant electrophilic reactivity toward nucleophilic species such as amines, thiols, and hydroxyl groups.
The ethyl ester portion of the molecule contributes lipophilicity and can be subsequently hydrolyzed to the corresponding benzoic acid or transformed through transesterification and amide-bond-forming reactions, giving synthetic chemists multiple handles for downstream elaboration. The meta substitution pattern on the benzene ring avoids steric crowding between the two substituents, facilitating predictable reactivity in further functionalization steps.
The compound is typically encountered as a white to off-white crystalline solid. Owing to the reactive chloroacetamide group, the material should be stored in a cool, dry environment, away from moisture and nucleophilic contaminants, to preserve chemical integrity during storage.
Synthetic Utility and Reactivity
The defining synthetic feature of Ethyl 3-(2-chloroacetamido)benzoate is the electrophilic chloroacetamide group. The α-haloamide motif is well-established in organic synthesis as a versatile handle for S-alkylation, N-alkylation, and O-alkylation reactions. Reaction with thiol nucleophiles, for instance, affords thioether-linked conjugates that are frequently encountered in protease inhibitor design and covalent probe chemistry. Similarly, reaction with secondary amines leads to α-aminoacetamide derivatives of value in peptidomimetic synthesis.
The compound can serve as a key precursor in the preparation of diketopiperazine frameworks and other nitrogen-containing heterocycles when bifunctional nucleophiles are employed. The ethyl ester provides an orthogonal site of reactivity: it can be selectively hydrolyzed under basic conditions to reveal the free carboxylic acid for subsequent amide coupling, or reduced to a benzyl alcohol for further elaboration.
In the context of covalent fragment-based drug discovery, chloroacetamide-bearing fragments have gained traction as mild, selective warheads targeting cysteine residues in proteins. Ethyl 3-(2-chloroacetamido)benzoate and structurally related analogs thus represent entry points into the preparation of such targeted covalent fragments.
Applications in Medicinal Chemistry and Drug Discovery
Chloroacetamide-functionalized aromatic building blocks occupy an important niche in medicinal chemistry, particularly in programs targeting enzyme active sites that contain reactive cysteine residues. The combination of an electrophilic warhead and a structurally defined aromatic scaffold allows researchers to design compounds with both binding affinity and covalent reactivity in a controlled manner.
Ethyl 3-(2-chloroacetamido)benzoate is suitable for use as an intermediate in the synthesis of candidate molecules for kinase inhibitor programs, ubiquitin pathway modulators, and other covalent drug discovery initiatives. The meta-aminobenzoate template is also found in pharmacophore models for several validated biological targets, lending the compound additional relevance as a starting material for structure–activity relationship (SAR) exploration.
Beyond covalent biology, the compound is useful as a bifunctional linker precursor in the preparation of antibody–drug conjugates (ADCs) and PROTACs, where orthogonal reactivity of the ester and the α-haloamide can be exploited sequentially. Researchers engaged in chemical biology and chemical proteomics may also employ this compound to generate activity-based probes.
Handling, Storage, and Safety Considerations
As with all α-haloamide reagents, Ethyl 3-(2-chloroacetamido)benzoate should be handled with appropriate laboratory precautions. The compound is a potential skin and eye irritant; personal protective equipment including chemical-resistant gloves, safety goggles, and a laboratory coat should be worn during handling. Operations generating dust or aerosols should be conducted in a well-ventilated fume hood.
For storage, keep the material in a tightly sealed container under cool (2–8 °C is advisable for long-term storage), dry conditions and away from strong nucleophiles, bases, and oxidizing agents. Exposure to moisture can lead to hydrolysis of the α-chloro group, degrading the reagent and reducing yield in downstream reactions. The compound should be allowed to equilibrate to room temperature before opening the container to prevent condensation-related degradation.
Disposal of waste material containing this compound should comply with local regulations for halogenated organic waste. Researchers should consult the Safety Data Sheet (SDS) provided by Aladdin Scientific for complete hazard information, first-aid measures, and disposal guidance specific to this product (SKU E697608).
Frequently asked questions
What is Ethyl 3-(2-chloroacetamido)benzoate used for in research?
It is primarily used as an electrophilic building block in organic and medicinal chemistry. Its reactive chloroacetamide group enables alkylation of nucleophiles such as thiols and amines, making it useful for synthesizing heterocycles, covalent drug candidates, activity-based probes, and bifunctional linkers for ADCs and PROTACs.
How should Ethyl 3-(2-chloroacetamido)benzoate be stored to maintain stability?
The compound should be stored in a tightly sealed container under cool, dry conditions, ideally at 2–8 °C for long-term storage. It should be kept away from moisture, strong nucleophiles, bases, and oxidizing agents, as exposure to these can cause degradation of the reactive chloroacetamide group. Allow the container to equilibrate to room temperature before opening to avoid condensation.
Can the ethyl ester group in this compound be selectively modified without affecting the chloroacetamide?
Yes, the ethyl ester and the chloroacetamide group offer orthogonal reactivity under appropriate conditions. The ethyl ester can be selectively hydrolyzed under mild basic aqueous conditions to give the free carboxylic acid, which can then be used in amide coupling reactions, while the chloroacetamide remains available for subsequent nucleophilic alkylation steps. Careful control of reaction conditions is required to achieve selectivity.
Is Ethyl 3-(2-chloroacetamido)benzoate suitable for cysteine-targeted covalent probe synthesis?
Yes, chloroacetamide groups are recognized as mild, selective electrophilic warheads for cysteine residues and are widely employed in covalent fragment-based drug discovery. Ethyl 3-(2-chloroacetamido)benzoate provides a convenient aromatic scaffold onto which this warhead is installed, making it a suitable starting material or intermediate for cysteine-targeted probe and inhibitor synthesis.
References
- Gehringer, M.; Laufer, S. A. Emerging and Re-Emerging Warheads for Targeted Covalent Inhibitors: Applications in Medicinal Chemistry and Chemical Biology. J. Med. Chem. 2019, 62, 5673–5724. doi:10.1021/acs.jmedchem.8b01153
- Tuley, A.; Fast, W. The Taxonomy of Covalent Inhibitors. Biochemistry 2018, 57, 3326–3337. doi:10.1021/acs.biochem.8b00315
- Mah, R.; Thomas, J. R.; Shafer, C. M. Drug Discovery Considerations in the Development of Covalent Inhibitors. Bioorg. Med. Chem. Lett. 2014, 24, 33–39. doi:10.1016/j.bmcl.2013.10.003
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