Butylurea: Properties, Applications & Lab Use Guide

Butylurea is a monosubstituted urea derivative bearing an n-butyl group that serves as a versatile building block in organic synthesis, medicinal chemistry, and materials research.

IUPAC Name

1-butylurea (butyl carbamoyl amine)

Molecular Formula

C5H12N2O

Molecular Weight

116.16 g/mol

CAS Number

592-31-4

Appearance

White to off-white crystalline solid

Solubility

Soluble in water, ethanol, and polar organic solvents

Functional Class

Monosubstituted urea; nitrogen-containing organic compound

Chemical Identity and Physical Properties

Butylurea (CAS 592-31-4), systematically named 1-butylurea, is a monoalkyl-substituted urea in which one hydrogen of the amino group in urea is replaced by an n-butyl chain. Its molecular formula is C₅H₁₂N₂O with a molecular weight of approximately 116.16 g/mol.

At ambient conditions, butylurea is a white to off-white crystalline solid. It exhibits moderate water solubility owing to its polar carbonyl and amine groups, and is also soluble in lower alcohols such as ethanol and methanol, as well as in other polar aprotic solvents. The compound possesses a higher melting point than simple aliphatic amines, a characteristic shared by the urea family due to intermolecular hydrogen bonding involving both N–H donors and the carbonyl oxygen acceptor.

The presence of the n-butyl substituent confers greater lipophilicity compared with urea itself, which can influence partitioning behavior and membrane permeability in biological assay contexts. Researchers should note that the compound is hygroscopic and should be stored in a cool, dry environment, tightly sealed, to prevent moisture uptake and decomposition.

Synthesis and Reactivity

Butylurea is most commonly prepared by the reaction of n-butylamine with urea or, alternatively, by the reaction of n-butylisocyanate with ammonia or water. The condensation of an amine with isocyanic acid or its equivalents is a classical route to monosubstituted ureas widely employed in both academic and industrial settings.

As a urea derivative, butylurea retains nucleophilic character at both nitrogen centers, enabling it to participate in condensation reactions with aldehydes and ketones, cyclization reactions to form heterocyclic scaffolds such as dihydropyrimidinones (as in Biginelli-type reactions), and acylation reactions to give ureido amides or related structures. The carbonyl group can also undergo hydrolysis under harsh acidic or basic conditions, regenerating n-butylamine and carbamic acid intermediates.

These reaction pathways make butylurea a useful intermediate for preparing pharmacologically active heterocycles and functionalized nitrogen-containing frameworks relevant to drug discovery programs.

Laboratory Applications

Butylurea finds application across several research domains. In medicinal chemistry, it serves as a building block for constructing urea-containing pharmacophores, which appear in a range of biologically active compounds including kinase inhibitors, herbicides, and antimicrobial agents. The urea motif is valued for its ability to form bidentate hydrogen bonds with protein residues, making urea-based fragments attractive in fragment-based drug discovery.

In materials science, alkyl ureas including butylurea have been explored as components of supramolecular assemblies, gelators, and co-crystal formers owing to their strong hydrogen-bond donating and accepting capacity. They can modulate crystal packing and solubility profiles of active pharmaceutical ingredients (APIs) when used as co-formers.

Butylurea is also used as a reference standard or model compound in studies of urea hydrolysis kinetics, soil nitrogen cycling research, and as a nitrogen source in certain biochemical assays. Its defined structure and straightforward reactivity make it a convenient model substrate for enzyme activity studies involving ureases and related hydrolases.

Safe Handling, Storage, and Regulatory Considerations

Butylurea is generally regarded as a low-hazard compound under standard laboratory conditions; however, routine safe-handling practices should always be observed. Researchers should wear appropriate personal protective equipment (PPE) including nitrile gloves, safety glasses, and a laboratory coat when handling the solid or solutions. Avoid inhalation of dust or aerosols, and work in a well-ventilated area or under a fume hood when weighing or transferring the material.

For storage, butylurea should be kept in a tightly closed container away from moisture, heat, and incompatible materials such as strong oxidizers and strong acids or bases. Recommended storage temperature is typically at room temperature (15–25 °C) in a dry environment; consult the product-specific Safety Data Sheet (SDS) provided by Aladdin Scientific for confirmed storage conditions and first-aid measures.

From a regulatory standpoint, butylurea is not currently classified as a controlled substance under major international frameworks; however, users should verify local regulations. Disposal should follow institutional and local environmental guidelines for organic nitrogen-containing compounds. Always consult the current SDS before use.

Procurement and Quality Specifications

Aladdin Scientific supplies butylurea (SKU: B152704) as a research-grade reagent. When evaluating a supplier for butylurea, key quality parameters to assess include: purity (typically reported by HPLC or GC), identity confirmation by NMR or IR spectroscopy, water content (Karl Fischer titration), and heavy-metal impurity profiles where relevant to the application.

For sensitive synthetic or biological applications, researchers should request a Certificate of Analysis (CoA) for each lot, confirming purity and key physical constants. Bulk quantities may be available upon request; contact Aladdin Scientific's technical sales team for pricing, lead times, and custom packaging options.

Proper documentation including CoA and SDS is provided with each shipment to support laboratory quality management systems and regulatory compliance requirements. Researchers working under GMP or GLP conditions should confirm whether research-grade material meets their specific validation requirements before use.

Frequently asked questions

What is butylurea used for in research?

Butylurea is used primarily as a synthetic building block in medicinal chemistry for constructing urea-containing pharmacophores, as a model substrate in enzyme (urease) activity studies, and as a component in supramolecular chemistry and co-crystal formulations. It also serves as a reference compound in soil nitrogen cycling and urea hydrolysis kinetics research.

How should butylurea be stored to maintain stability?

Butylurea should be stored in a tightly sealed container at room temperature (15–25 °C) in a dry environment, away from moisture, strong acids, bases, and oxidizing agents. Because the compound is hygroscopic, exposure to humid air should be minimized. Always refer to the product SDS for confirmed storage conditions.

What solvents are suitable for dissolving butylurea?

Butylurea is soluble in water, ethanol, and methanol due to its polar urea functional group. It also dissolves in other polar organic solvents such as DMSO. It has limited solubility in nonpolar solvents such as hexane or diethyl ether.

Is butylurea the same as n-butylurea or 1-butylurea?

Yes. Butylurea, n-butylurea, and 1-butylurea all refer to the same compound with CAS number 592-31-4, in which the n-butyl group is attached to one nitrogen of the urea moiety. Different nomenclature systems and databases may use these names interchangeably.

How do I request a Certificate of Analysis (CoA) for Aladdin's butylurea?

You can request a Certificate of Analysis for butylurea (SKU: B152704) by contacting Aladdin Scientific's customer service team with your lot number. CoAs are also typically available for download on the product page of the Aladdin Scientific website.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992. (General urea chemistry and monosubstituted urea synthesis)
2. Kaur, N. Urea and its derivatives in the synthesis of heterocycles. Synthetic Communications, 2014. (Butylurea and related ureas as heterocycle precursors)
3. Sigel, H.; Martin, R. B. Urea as a ligand and its role in hydrogen bonding: a review. Chemical Society Reviews, general reference. (Hydrogen bonding properties of urea derivatives)
4. Aladdin Scientific. Product page and Safety Data Sheet for Butylurea, SKU B152704. https://www.aladdin-e.com

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.