1-(4-Ethylphenyl)thiourea: Properties, Synthesis & Applications

1-(4-Ethylphenyl)thiourea is an aryl-substituted thiourea compound of growing interest in synthetic organic chemistry and biological research due to its versatile reactivity and potential pharmacological properties.

Chemical Name

1-(4-Ethylphenyl)thiourea

SKU

E1071772

Molecular Formula

C9H12N2S

Molecular Weight

180.27 g/mol

Functional Class

Aryl thiourea derivative

Key Functional Groups

Thiourea (-NH-C(=S)-NH2), para-ethylphenyl ring

Primary Research Uses

Organic synthesis intermediate, chelation chemistry, biological activity screening

Chemical Structure and Physical Properties

1-(4-Ethylphenyl)thiourea belongs to the class of monosubstituted aryl thioureas, characterized by a thiourea functional group (–NH–C(=S)–NH₂) directly attached to a para-ethyl-substituted phenyl ring. Its molecular formula is C₉H₁₂N₂S, corresponding to a molecular weight of approximately 180.27 g/mol.

The compound typically presents as a white to off-white crystalline solid at room temperature. The thiourea moiety confers both hydrogen-bond donor and acceptor capabilities through its N–H groups and the thiocarbonyl sulfur atom, making the molecule highly amenable to supramolecular interactions and coordination chemistry. The para-ethyl substituent on the phenyl ring influences the electron density of the aromatic system and the overall lipophilicity of the molecule relative to unsubstituted phenylthiourea analogues.

Thiourea derivatives generally display moderate solubility in polar aprotic and protic solvents such as DMSO, DMF, and ethanol, while showing limited solubility in nonpolar solvents. Specific physical constants such as melting point and solubility profile for E1071772 should be confirmed against the certificate of analysis provided with each lot.

Synthesis and Preparation Routes

Aryl thioureas such as 1-(4-Ethylphenyl)thiourea are most commonly prepared by the condensation of the corresponding aryl amine—in this case, 4-ethylaniline—with ammonium thiocyanate or with thiocarbamoylating agents such as benzoyl isothiocyanate followed by hydrolysis, or directly with ammonium thiocyanate under acidic conditions.

The simplest and most scalable route involves reacting 4-ethylaniline with ammonium thiocyanate in an aqueous acidic medium. The amine is first protonated to form its salt, which then undergoes a Mumm-type rearrangement or direct condensation with thiocyanate anion to yield the aryl thiourea product after neutralization and recrystallization.

Alternative routes include reaction of 4-ethylaniline with carbon disulfide in the presence of ammonia, or use of thiophosgene-derived intermediates, though these are less commonly employed at laboratory scale due to toxicity and handling considerations. Purification is typically achieved by recrystallization from ethanol or ethanol/water mixtures, affording the product in good yield and high purity.

Biological Activity and Research Applications

Thiourea derivatives as a chemical class have attracted sustained interest in medicinal chemistry and pharmacological research owing to their broad spectrum of biological activities. Aryl thioureas have been reported to exhibit antimicrobial, antifungal, anticancer, and enzyme-inhibitory properties in various in vitro screening studies. The specific substitution pattern on the aromatic ring modulates potency, selectivity, and pharmacokinetic profile.

1-(4-Ethylphenyl)thiourea, as a para-alkyl-substituted aryl thiourea, may serve as a useful scaffold or intermediate in the development of bioactive compounds. Thioureas are known inhibitors of certain metalloenzymes and have been explored as pharmacophores targeting carbonic anhydrase, urease, and various kinases. Additionally, the compound's ability to chelate metal ions makes it relevant to coordination chemistry studies and the development of metal-based catalysts or sensors.

In synthetic chemistry, 1-(4-Ethylphenyl)thiourea can function as a building block for the preparation of heterocyclic compounds such as benzimidazoles, thiazolines, and aminothiazoles through condensation reactions with appropriate electrophiles. It may also serve as an organocatalyst or ligand precursor in asymmetric synthesis applications.

Researchers are advised to consult primary literature for specific biological activity data relevant to their application, as the exact pharmacological profile of 1-(4-Ethylphenyl)thiourea specifically may require dedicated experimental validation.

Handling, Storage, and Safety Considerations

As with all thiourea-containing compounds, standard laboratory safety precautions should be observed when handling 1-(4-Ethylphenyl)thiourea. Thioureas in general may exhibit mild to moderate irritant properties toward skin, eyes, and the respiratory tract. Personal protective equipment including nitrile gloves, safety glasses, and a laboratory coat should be worn at all times during handling.

The compound should be stored in a tightly sealed container away from moisture, heat, and direct light. Storage at room temperature in a cool, dry environment is generally appropriate for solid aryl thioureas, though researchers should consult the specific storage recommendations stated on the product label or certificate of analysis for E1071772.

Disposal of thiourea-containing waste should be carried out in accordance with local institutional and regulatory guidelines for organic chemical waste. Users should consult the Safety Data Sheet (SDS) for E1071772, available from Aladdin Scientific, for complete hazard classification, first-aid measures, and disposal instructions prior to use.

Frequently asked questions

What is 1-(4-Ethylphenyl)thiourea used for in research?

1-(4-Ethylphenyl)thiourea is primarily used as a synthetic intermediate for the preparation of heterocyclic compounds and as a scaffold in medicinal chemistry research. It may also serve as a ligand precursor in coordination chemistry and as an organocatalyst in asymmetric synthesis.

How should 1-(4-Ethylphenyl)thiourea (E1071772) be stored?

The compound should be stored in a tightly sealed container in a cool, dry place away from moisture and direct sunlight. Specific storage conditions for E1071772 should be confirmed by consulting the product label or the certificate of analysis provided by Aladdin Scientific.

What solvents are suitable for dissolving 1-(4-Ethylphenyl)thiourea?

Aryl thiourea derivatives typically dissolve well in polar solvents such as DMSO, DMF, and ethanol. Solubility in water and nonpolar solvents is generally limited. Researchers should determine solubility experimentally for their specific application and consult the SDS or technical datasheet for guidance.

Is 1-(4-Ethylphenyl)thiourea related to thyroid peroxidase inhibition?

Certain thiourea derivatives are known to inhibit thyroid peroxidase and have been studied as antithyroid agents. While aryl thioureas as a class share structural features with known antithyroid compounds, specific inhibitory activity of 1-(4-Ethylphenyl)thiourea against thyroid peroxidase would require experimental confirmation. Researchers should review relevant primary literature before drawing conclusions.

References

1. Schofield, K. (1967). Heteroaromatic Nitrogen Compounds: Pyrroles and Pyridines. Plenum Press. [General reference for thiourea chemistry and heterocyclic synthesis]
2. Rao, A. et al. (2006). Synthesis and biological evaluation of thiourea derivatives as antimicrobial agents. European Journal of Medicinal Chemistry. [Representative study on aryl thiourea biological activity; specific relevance to 1-(4-Ethylphenyl)thiourea not confirmed]
3. Aladdin Scientific. Product Datasheet: 1-(4-Ethylphenyl)thiourea, SKU E1071772. [Primary product documentation; consult current lot CoA for verified physical data]

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