Benzamide: Properties, Uses & Lab FAQs

Benzamide is the simplest aromatic amide, widely used as a chemical intermediate and reference standard in organic synthesis, pharmaceutical research, and biochemical studies.

Chemical Formula

C₇H₇NO

Molecular Weight

121.14 g/mol

CAS Number

55-21-0

Melting Point

Approximately 128–130 °C

Appearance

White crystalline solid

Solubility

Slightly soluble in water; soluble in ethanol, acetone, and chloroform

SKU (Aladdin)

B110551

What Is Benzamide and What Are Its Key Chemical Properties?

Benzamide (CAS 55-21-0) is the amide derivative of benzoic acid, with the molecular formula C₇H₇NO and a molecular weight of 121.14 g/mol. It appears as a white crystalline solid at room temperature and carries a faint, characteristic aromatic odor.

Key physicochemical properties include a melting point of approximately 128–130 °C and slight solubility in water, with considerably better solubility in polar organic solvents such as ethanol, acetone, and chloroform. The amide bond in benzamide is relatively stable toward hydrolysis under neutral aqueous conditions but can be cleaved under strongly acidic or basic conditions at elevated temperatures.

Structurally, the planar amide linkage conjugated with the phenyl ring makes benzamide a useful model compound for studying amide resonance and hydrogen-bonding interactions in crystal engineering and computational chemistry.

What Are the Primary Research and Industrial Applications of Benzamide?

Benzamide serves multiple roles across chemistry and biology:

• Organic synthesis intermediate: Benzamide is a versatile building block for preparing pharmaceuticals, agrochemicals, and specialty chemicals. It participates in reactions such as Beckmann rearrangement, directed C–H activation, and condensation reactions to form heterocyclic scaffolds.
• Directed C–H functionalization: The amide group in benzamide acts as a powerful directing group in transition-metal-catalyzed C–H bond activation, enabling regioselective functionalization of the aromatic ring. This application has attracted significant interest in modern synthetic methodology.
• Pharmaceutical relevance: The benzamide motif is embedded in numerous drug molecules, including antipsychotics, antiemetics, and antifungal agents, making benzamide itself a key reference standard and precursor in medicinal chemistry programs.
• Biochemical research: Benzamide and its derivatives have been investigated as PARP (poly ADP-ribose polymerase) inhibitors, relevant to cancer biology research.
• Reference standard: High-purity benzamide is used as a melting-point calibration standard and as an analytical reference in HPLC and NMR method development.

How Should Benzamide Be Stored and Handled Safely in the Laboratory?

Storage: Benzamide should be stored in a tightly sealed container in a cool, dry, well-ventilated area away from strong oxidizers, acids, and bases. Storage at room temperature (15–25 °C) under inert atmosphere is recommended for long-term preservation of purity. Protect from moisture to prevent gradual hydrolysis.

Handling precautions: Although benzamide has relatively low acute toxicity, standard laboratory personal protective equipment (PPE) should be used, including gloves, safety glasses, and a laboratory coat. Avoid generating dust, and work in a fume hood when handling significant quantities or when heating the compound.

Disposal: Dispose of benzamide-containing waste in accordance with local institutional and governmental chemical waste regulations. Do not pour down the drain without verifying local permissibility.

First aid: In case of skin or eye contact, flush immediately with copious water. If inhaled, move to fresh air. Consult the Safety Data Sheet (SDS) for full hazard information before use.

How Can Benzamide Purity and Identity Be Verified?

Several analytical techniques are routinely used to confirm the identity and purity of benzamide:

• Melting point determination: Benzamide has a well-established melting point of approximately 128–130 °C. A sharp, reproducible melt within this range is a strong indicator of high purity.
• HPLC: Reverse-phase HPLC with UV detection (typically at 225–254 nm) provides quantitative purity assessment. Aladdin's benzamide (B110551) is characterized for purity by HPLC prior to release.
• NMR spectroscopy: ¹H NMR in DMSO-d₆ or CDCl₃ shows characteristic signals for the phenyl protons (δ ~7.4–8.0 ppm) and the amide NH₂ protons (broad signal, δ ~7.5–8.0 ppm). ¹³C NMR confirms the carbonyl carbon at approximately δ 167 ppm.
• IR spectroscopy: Strong amide I and amide II bands (C=O stretch near 1660 cm⁻¹ and N–H bend near 1590 cm⁻¹) are diagnostic.
• Mass spectrometry: ESI or EI-MS shows a molecular ion at m/z 121 consistent with C₇H₇NO.

Ordering and Availability of Benzamide from Aladdin Scientific

Aladdin Scientific supplies benzamide under SKU B110551. The product is available in multiple pack sizes to suit laboratory-scale research through larger preparative needs. Each lot is quality-controlled for purity and accompanied by a Certificate of Analysis (CoA).

To place an order, visit the Aladdin Scientific website, search by product name or SKU B110551, select your required quantity, and proceed through the standard checkout process. Institutional purchase orders are accepted, and volume pricing may be available — contact Aladdin's sales team for quotations on bulk quantities.

For technical questions about specifications, alternative grades, or custom packaging, contact Aladdin Scientific's technical support team via the website or email. Safety Data Sheets (SDS) and Certificates of Analysis are available for download from the product page.

Frequently asked questions

What solvents are suitable for dissolving benzamide in lab experiments?

Benzamide is slightly soluble in cold water but dissolves readily in warm water, ethanol, methanol, acetone, chloroform, and dimethyl sulfoxide (DMSO). For aqueous biological assays, DMSO stock solutions are commonly prepared and then diluted into aqueous buffer, keeping the final DMSO concentration low to minimize interference.

Is benzamide safe to handle, and what PPE is required?

Benzamide has relatively low acute toxicity, but it should be treated as a chemical hazard requiring standard precautions. Researchers should wear nitrile gloves, safety glasses, and a laboratory coat when handling it. Dust generation should be minimized, and operations involving larger quantities or heating should be performed in a ventilated fume hood. Always consult the current Safety Data Sheet (SDS) before use.

Can benzamide be used as a directing group in C–H activation reactions?

Yes. The amide nitrogen in benzamide coordinates to transition metals such as palladium, rhodium, and ruthenium, directing metalation to the ortho position of the phenyl ring. This makes benzamide a classic substrate and model compound for studying and developing directed C–H functionalization methodologies, including C–H arylation, alkylation, and annulation reactions.

What is the shelf life of benzamide, and how should it be stored long-term?

When stored properly in a tightly sealed container at room temperature in a cool, dry environment away from moisture and incompatible materials, benzamide is stable for multiple years. Exposure to moisture can lead to slow hydrolysis over extended periods. Checking purity by melting point or HPLC before critical experiments is recommended if the material has been stored for a long time.

What analytical grade or purity is available for Aladdin's benzamide (B110551)?

Aladdin Scientific's benzamide (SKU B110551) is supplied as a high-purity reagent grade product. The exact purity specification is stated on the product Certificate of Analysis (CoA), which is available from the Aladdin website or upon request. Researchers requiring a specific purity threshold for critical applications should verify the CoA before placing an order.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley: New York, 1992.
2. Colby, D. A.; Bergman, R. G.; Ellman, J. A. Rhodium-Catalyzed C–C Bond Formation via Heteroatom-Directed C–H Bond Activation. Chem. Rev. 2010, 110, 624–655. doi:10.1021/cr900005n
3. Rouleau, M.; Tan, A.; Bhattacharya, G.; Bhattacharya, S. Benzamide class of PARP inhibitors. Expert Opin. Ther. Pat. — general reference; specific citation details require verification.
4. Lide, D. R. (Ed.) CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2003.

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