Chemists have worked with piperidine-based structures since the late 1800s, when research into alkaloids and their synthetic derivatives really started to take off. The piperidine ring shows up in a broad array of natural bioactive compounds. By the early 20th century, chemical manufacturers refined routes to access basic and elaborated piperidine structures. Ethyl 4-oxopiperidine-1-carboxylate entered the industry toolkit as a useful intermediate for pharmaceuticals and agrochemicals as attention grew toward heterocycles that could be easily modified. Over decades, more practical and scalable methods made these molecules more accessible and appealing for routine laboratory and pilot-scale use.
Chemists prize Ethyl 4-oxopiperidine-1-carboxylate not just for its core ring system but for the way the ketone and ester groups add versatility. It opens up routes to a variety of final compounds depending on the transformations required. Manufacturers that deliver this intermediate typically serve drug discovery teams, medicinal chemistry groups, and sometimes materials researchers looking for new polymer building blocks. Demand for the compound reflects its value as a scaffold for custom small-molecule synthesis.
Ethyl 4-oxopiperidine-1-carboxylate usually shows up as a light yellow to transparent oily liquid or sometimes a low-melting solid, depending on storage and purity. Odorless or faintly sweet, it dissolves readily in common solvents: ethyl acetate, dichloromethane, or even a bit in ethanol. Its most characteristic feature—a reactive ketone at the 4-position—means it gets involved in nucleophilic addition and condensation reactions. The ester can be cleaved or transformed for further tailoring, so researchers can adapt it for new targets. Its boiling point lands in the middle range for organic liquids, allowing simple distillation when purification is required. Moisture doesn’t break it down quickly, but it performs best with careful storage away from acid, base, or sunlight.
Suppliers focus on critical quality measures: clear labeling with CAS number (877718-18-8), lot identification, purity percentage, residual solvent profile, and expiry or retest date. Many vendors confirm analytical specs by NMR, GC-MS, or HPLC, targeting a purity of 95% or higher. For labs synthesizing analogs or scaling up new drug leads, knowing the optical rotation, melting or boiling point, and impurity levels makes a world of difference in planning. Proper labeling also covers handling risk, storage conditions (room temperature, sealed from air and light), and regulatory classification.
Most synthetic routes start from cheap, accessible raw materials. Chemists typically select N-protected piperidone derivatives, perform a selective oxidation or acylation at the 4-position, then introduce the ethyl ester using a standard esterification or transesterification step. Traditional work-up includes extraction, washing, and distillation or flash chromatography to clean up the product. Pilot-scale production bridges batch and continuous flow setups, depending on the needs of end users. Experienced chemists always look for routes that minimize hazardous byproducts and improve yield.
The core structure lends itself to plenty of downstream chemistry. That carbonyl group at the 4-position is a hotspot for nucleophilic attack—think reductive amination, aldol-type reactions, or conjugate additions. The ethyl ester has its own charm, offering a handle for hydrolysis or transformation to amides, acids, or even other esters. Medicinal chemists often use the scaffold to introduce new substituents, exploiting the ring’s rigidity and the orthogonal modification points. Carefully chosen reagents and conditions allow building diverse libraries to test for new bioactive compounds.
Anyone searching for this compound in chemical databases encounters several names: Ethyl 1-piperidinecarboxylate-4-one, Piperidine-1-carboxylic acid, 4-oxo-, ethyl ester, or simply 4-Oxopiperidine-1-carboxylic acid ethyl ester. Each naming style reflects a different perspective—whether the focus is on the ring, the ester, or the overall functionalization. Catalog entries may also refer to it by internal numbering systems or as part of a “building block” or “starting material” collection.
Lab workers treat this intermediate with standard organic precautions: nitrile gloves, chemical splash goggles, and fume hood work. While it doesn’t carry extreme toxicity or volatility at room temperature, its ketone group can react with strong oxidants or reducing agents, sometimes producing unexpected byproducts. Frequent risks involve inhalation of vapors during rota-evaporation or accidental skin contact in the event of a spill. Material Safety Data Sheets list environmental and disposal guidelines, urging collection in organic waste containers and avoidance of wastewater drains. Some facilities automate handling to cut down on exposure.
Drug development teams rely heavily on substituted piperidine intermediates for creating new lead candidates. Ethyl 4-oxopiperidine-1-carboxylate has found roles in CNS-targeted molecules, pain modulators, and even antiviral scaffolds. Chemists in crop science appreciate its ring stability and modifiability, often reengineering it for new plant protectants or growth regulators. A handful of researchers explore its use in preparing specialty polymers or advanced materials. Most of its demand originates from sectors that can exploit its aromatic-free, non-planar backbone and ease of customization for structure-activity relationship studies.
Every year, new publications and patents cite this compound as a core building block. Research teams often tweak the initial structure, seeking enhanced target affinity or metabolic stability in biologically active molecules. Automated synthesis platforms benefit from the reproducibility of reactions based on this scaffold, supporting high-throughput screening. Collaborative projects between academia and biotech startups push its chemistry into new areas, seeking catalytically-efficient, green modifications. Published research continues to refine preparation methods that avoid noxious reagents or intermediate purification bottlenecks.
Data on toxicity remains limited since most exposure happens in controlled lab settings. Experienced toxicologists perform classic dose-response tests in rodents and assess absorption, distribution, metabolism, and excretion properties when needed. Most acute and sub-chronic results classify it as low hazard for skin or inhalation, though some ketones in this class can act as mild mucosa irritants at high concentrations. No evidence links it with carcinogenicity or reproductive toxicity under standard use, but prudent chemistry means minimizing exposure, especially in unventilated spaces.
More synthetic and medicinal work will demand these types of core intermediates as discovery pipelines look for novel shapes beyond flat aromatics. As green chemistry gains a bigger foothold, scalable routes with less hazardous reagents or recyclable solvents carry more weight in selection decisions. Digital chemistry and AI-aided drug design favor easily modifiable, diverse building blocks—which puts compounds like Ethyl 4-oxopiperidine-1-carboxylate in the front line for new reaction exploration. Industry regulations and safety standards keep pushing for better hazard labeling and safer handling, making suppliers who invest in training and improved documentation stand out. The next years will likely see this molecule show up in even more patents for medicines, crop protectants, or material science innovations.
