3-Acetoxy-4-nitrobenzoic acid - ≥95% , CAS No.51257-24-0

CAS: 51257-24-0 Cat. No.: A952908 Formule: C₉H₇NO₆ Poids moléculaire: 225.150

GRADE & PURITY ≥95%

Storage

Room temperature

Specifications

Spécifications et pureté

≥95%

Conditions de stockage de stockage

Room temperature

Pureté

≥95%

Noms et identifiants

Sourires canoniques

CC(=O)OC1=C(C=CC(=C1)C(=O)O)[N+](=O)[O-]

IUPAC Name

3-acetyloxy-4-nitrobenzoic acid

InChIKey

CXXFEUYSCNJQFE-UHFFFAOYSA-N

INCHI

1S/C9H7NO6/c1-5(11)16-8-4-6(9(12)13)2-3-7(8)10(14)15/h2-4H,1H3,(H,12,13)

Poids moléculaire

225.150

Propriétés chimiques et physiques

• Poids moléculaire: 225.150 g/mol
• XLogP3: 1.500
• Hydrogen Bond Donor Count: 1
• Hydrogen Bond Acceptor Count: 6
• Rotatable Bond Count: 3
• Exact Mass: 225.027 Da
• Monoisotopic Mass: 225.027 Da
• Topological Polar Surface Area: 109.000 Ų
• Heavy Atom Count: 16
• Formal Charge: 0
• Complexity: 310.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 0
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

Application Protocols

No tested biological application protocols (e.g., WB, IHC, IF, FC) are specified for this small-molecule reagent. For synthetic and analytical use:

• Preparing stock solutions: Dissolve in DMSO, DMF, or acetonitrile to a convenient concentration (e.g., 10–100 mM), filter if necessary through 0.22 µm PTFE, and store aliquots as appropriate.
• Reaction setup: Dry glassware and anhydrous solvents are advised for moisture-sensitive activations (acid chloride formation, carbodiimide couplings). Titrate base equivalents to minimize acetoxy cleavage.

Refer to primary literature for detailed, reaction-specific procedures involving 3-acetoxy-4-nitrobenzoic acid or close analogs.

Biological Roles

This compound is a small, synthetic nitroaromatic carboxylic acid used as a research chemical building block. No endogenous biological role is expected.

General context (literature-based; not product-specific claims):

• Functional group effects: The nitro group is strongly electron-withdrawing and can modulate acidity and lipophilicity of aromatic acids, properties often explored in SAR studies. The acetoxy group can function as a masked phenol, offering a handle for later deprotection to the corresponding hydroxy derivative.
• Biotransformations: In biological systems, aryl acetates can undergo esterase-mediated hydrolysis to phenols; nitro groups can be reduced by nitroreductases under certain conditions. These are generic observations and not claims of in vivo activity or suitability for clinical use.

No biological testing data, targets, or activities are provided for this item. It is supplied strictly for research use only.

Buffer Applications

Not typically applicable. 3-Acetoxy-4-nitrobenzoic acid is a hydrophobic, substituted aromatic acid used as a synthetic building block rather than a buffering agent. While carboxylic acids can, in principle, form conjugate acid/base pairs, this compound’s low aqueous solubility and additional reactive functionality (acetoxy, nitro) make it impractical for preparing laboratory buffers. For buffer needs, select dedicated buffering systems (e.g., acetate, phosphate, Tris) with well-characterized pKa and solubility profiles.

Green Alternatives

Context: This product is a solid building block rather than a process solvent. Greener considerations mainly concern choice of reagents, solvents, and transformations used with it.

Greener choices (literature/general):

• Solvents: Prefer lower-toxicity, more sustainable solvents where feasible.
  • Ethyl acetate, 2-MeTHF, CPME, and propylene carbonate are greener alternatives to chlorinated solvents; water/IPA mixtures may work for crystallizations.
  • For polar media, consider NBP or Cyrene as greener alternates to DMF/DMSO, subject to performance.
• Coupling reagents: Avoid benzotriazole-based additives (HOBt/HOAt) due to explosivity; use OxymaPure with EDC or COMU/BTFFH alternatives while managing waste.
• Activation strategies: Redox-active ester (RAE) formation followed by photoredox decarboxylative couplings can reduce need for stoichiometric metal halides.
• Reductions: If reducing the nitro group, catalytic hydrogenation (H2, Pd/C) can be cleaner than metal–acid reductions, provided selectivity toward the acetoxy is maintained.

Example comparison (general):

• DMF vs. Cyrene: Cyrene offers lower toxicity/biodegradability but different polarity/boiling point; solubility and reactivity must be re-optimized.
• DCM vs. EtOAc: EtOAc is biodegradable with lower environmental impact; often a drop-in for extractions and some reactions.

Trade-offs: Greener solvents may alter rates/selectivity (e.g., acetoxy stability in alcohols). Perform small-scale trials to confirm performance.

Pharmaceutical Uses

No pharmacopeial grade or excipient role is specified for this item; refer to CoA/Spec Sheet. This compound is a research-grade building block and is not offered for clinical or therapeutic use.

General formulation context (informational):

• As a functionalized benzoic acid, it may be used in discovery chemistry to prepare analog libraries. Any discussion of API or excipient use would require defined grades, compendial compliance (e.g., USP/Ph. Eur.), impurity profiles, and stability studies—none of which are specified here.

Therefore, limit use to non-clinical laboratory research.

Physical Properties

Item-specific specifications: Not specified for this item; refer to CoA/Spec Sheet for lot-specific values (e.g., melting point, elemental analysis, water content, residual solvents).

Literature/general reference values (for planning only; not product specifications):

• State at ambient conditions: Typically a crystalline nitroaromatic carboxylic acid solid.
• Approximate molecular weight: ~225.16 g/mol (for C9H7NO6).
• Acid–base: Contains a benzoic acid moiety (typical pKa for para-substituted nitrobenzoic acids ~2.2–3.5, literature range; electron-withdrawing nitro lowers pKa vs benzoic acid). Exact pKa for this specific substitution pattern not verified here.
• Solubility tendencies: Expected low solubility in water; better solubility in polar aprotic organic solvents (e.g., acetonitrile, DMF, DMSO, acetone, ethyl acetate) and in alcohols upon heating; deprotonated forms dissolve in basic aqueous media. Quantitative solubilities are not established here.

Do not treat these literature notes as acceptance criteria. For critical work (e.g., crystallization design, HPLC prep), determine actual mp/solubility with a small test or consult the CoA.

Quality and Grades

Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.

Guidance for interpreting grades (general information):

• Analytical/AR grade: Emphasizes low inorganic/organic impurities suitable for quantitative analysis.
• Reagent grade: Suitable for general synthetic applications.
• HPLC grade or LC–MS grade (for solvents/volatiles): Specifies very low UV background and trace impurities; typically not applicable to solid building blocks like this, unless stated.
• Purity reporting: For organic solids, purity may be by HPLC/GC area% or qNMR; residual solvents, water (KF), and identity (1H/13C NMR, IR, MS) are common.
• Stabilizers: None indicated for this item. If a stabilizer were present, it would be disclosed on the CoA; stabilizers can affect reactivity (e.g., base-sensitive or nucleophile-sensitive steps).

Recommendations:

• For sensitive synthetic sequences (e.g., late-stage functionalization, medicinal chemistry SAR), request a current CoA for assay, related substances, and residual solvents.
• If chromatography-grade purity or metal traces are critical, specify acceptance criteria at purchase; metal content and UV-cutoff are Not specified for this item; refer to CoA/Spec Sheet.

Reaction and Applications

Use-case context: 3-Acetoxy-4-nitrobenzoic acid is an electrophile-rich, functionalized aromatic acid valuable as a building block in organic synthesis and medicinal chemistry research. No manufacturer applications were provided; the following are literature-style possibilities consistent with its functionality.

Potential applications (literature/general):

• Protecting-group strategy: The 3-acetoxy substituent can serve as a phenolic protecting group. Deprotection to the 3-hydroxy derivative is typically achieved with mild base (e.g., K2CO3/MeOH) or aminolysis, enabling late-stage diversification.
• Cross-coupling after activation: The 4-nitro group is a strong electron-withdrawing group facilitating SEAr deactivation but enabling SNAr at suitably activated positions if additional leaving groups are introduced. Alternatively, convert the acid to acid chloride (SOCl2, (COCl)2) or to redox-active esters (e.g., NHP esters) for decarboxylative couplings (Ni/photoredox).
• Amide/ester formation: The carboxylic acid can be coupled to amines or alcohols using carbodiimides (EDC/HOBt, DIC, or DCC) or uronium reagents (HATU, TBTU). Control base strength to avoid acetyl migration or hydrolysis.
• Nitration chemistry handle: The nitro group can be reduced (e.g., Fe/AcOH, catalytic hydrogenation) to the corresponding aniline to access 4-amino analogs, enabling diazotization or cross-coupling after conversion to aryl diazonium salts (literature practice; verify compatibility with acetoxy).
• Late-stage diversification: Directed ortho-metalation is discouraged by strong deactivation; however, decarboxylative borylation/arylation via activated esters offers alternatives to access 3-acetoxy-4-nitroaryl derivatives.

Always evaluate stability of the acetoxy group under the chosen conditions.

Reaction Conditions

General literature guidance (not product specifications):

• Amide coupling: EDC·HCl (1.1–1.5 equiv) + Oxyma (1.1–1.5 equiv) with DIPEA (2–3 equiv) in DMF or NMP, 0–25 °C, 1–16 h. Alternatively HATU (1.1 equiv)/DIPEA in DMF at 0–25 °C. Monitor for acetoxy stability; avoid strong nucleophiles that could cleave the acetate.
• Acid chloride formation: (COCl)2 (1.5–2.0 equiv) with catalytic DMF in DCM or toluene, 0–25 °C, 1–3 h; then acylation of nucleophile at 0–25 °C. Ensure exclusion of water.
• Acetoxy deprotection: K2CO3 or Na2CO3 in MeOH/THF (or MeOH alone), 0–25 °C, minutes to hours; or aminolysis with primary amines. Work under mild conditions to avoid saponifying newly formed esters elsewhere.
• Nitro reduction: H2 (1–3 atm), Pd/C (5–10 wt%), EtOAc or EtOH, 20–40 °C, 1–6 h; or Fe/AcOH or SnCl2/HCl at reflux as alternatives. Validate selectivity versus potential acetate cleavage.
• RAE-mediated decarboxylation: Convert to NHP ester (DIC, NHP, DMAP, DCM), then Ni/photoredox with appropriate partners (e.g., borylation with B2pin2), blue LEDs, rt to 40 °C, 4–16 h.

Solvent and base choices strongly influence chemoselectivity given the presence of both acid and ester functions. Conduct small-scale trials and monitor by LC–MS or HPLC.

Safety and Handling

Item-specific hazard data: Not specified for this item; refer to the product SDS for authoritative GHS classification, signal word, H/P statements, and pictograms.

General laboratory safety guidance for nitroaromatic carboxylic acids (informational only):

• Hazards: Nitroaromatics and organic acids can be irritating to skin, eyes, and respiratory tract. Dust may cause mechanical irritation. Avoid inhalation of particulates and contact with skin/eyes.
• PPE: Use lab coat, appropriate gloves (e.g., nitrile), and splash-resistant eye protection. Handle powders in a fume hood or with local exhaust to minimize dust exposure.
• Incompatibilities: Avoid strong reducing agents (which may reduce nitro groups), strong bases (can form salts; exotherm on neutralization), strong oxidizers, and reactive acylation/deacylation catalysts if stability is critical. Store away from heat and ignition sources.
• First aid (overview): If inhaled, move to fresh air; seek medical attention if symptoms persist. For skin/eye contact, rinse with water for at least 15 minutes and remove contaminated clothing. If ingested, rinse mouth; do not induce vomiting; seek medical attention.
• Fire response: Use CO2, dry chemical, or foam. Nitroaromatics may decompose under fire conditions releasing NOx; firefighters should wear self-contained breathing apparatus.

Always defer to the SDS for the specific product and follow institutional EHS policies.

Solvent Selection

Applicability: This product is a polar, aromatic carboxylic acid bearing an acetoxy and nitro substituent. It is best handled as a solid and dissolved in suitable organic solvents or in basic aqueous media as its carboxylate salt.

General solvent behavior (literature-based):

• Polar aprotic solvents: DMSO, DMF, NMP, acetonitrile, and acetone typically provide good solubility for reaction setup and analytical stock solutions.
• Esters/ethers: Ethyl acetate and THF often dissolve nitroaryl acids; solubility may improve on gentle heating.
• Alcohols: Methanol, ethanol, and isopropanol can dissolve upon warming; be mindful of potential transesterification of the acetoxy under strongly basic or acidic conditions.
• Aqueous media: Poor solubility at neutral pH; readily solubilized by converting to its carboxylate with bases (e.g., NaHCO3/Na2CO3) for extractions or reactions.

Selection tips:

• For nucleophilic substitutions or coupling reactions, prefer polar aprotics (DMF/DMSO) for rate enhancement and solubility.
• For workups and crystallizations, ethyl acetate/hexanes or EtOAc/IPA mixtures are common starting points; adjust based on empirical solubility tests.
• Avoid highly basic alcoholic conditions if preserving the acetoxy group is essential; consider milder bases in aprotic media.

All solvent choices should be validated experimentally for your specific substrate loadings and temperature profile.

Storage and Reconstitution

Item-specific storage (from Product Data):

• Storage conditions: Room temperature.
• Shipped in: Not specified for this item; refer to CoA/Spec Sheet.
• Appearance: Not specified for this item; refer to CoA/Spec Sheet.

General guidance for this compound class:

• Keep container tightly closed in a dry, well-ventilated place. Protect from moisture and prolonged exposure to strong light or heat.
• If preparing solutions: Use dry, oxygen-free solvents when needed for sensitive transformations. For DMSO/DMF stock solutions, store in amber vials at 2–8 °C or at −20 °C for long-term, if compatible; allow to equilibrate to room temperature before opening to minimize condensation. Avoid repeated freeze–thaw by aliquoting.
• Stability notes: The acetoxy group can hydrolyze under basic aqueous conditions and at elevated temperatures. Avoid strong acids/bases during storage. Carboxylic acid is generally stable under ambient conditions when kept dry.

For definitive shelf-life and retest period, consult the CoA for the specific lot.

Structure and Identity

Item-specific (from Product Data):

• SKU: A952908
• Product name: 3-Acetoxy-4-nitrobenzoic acid
• CAS: 51257-24-0
• PubChem CID: 18188084
• InChIKey: 56531 (as provided)
• Storage: Room temperature
• Research use: For research use only

Literature/computed identity (for reference; not item specifications):

• Molecular formula (literature): C9H7NO6
• Molecular weight (literature): ~225.16 g/mol
• Representative SMILES (literature): O=C(O)c1ccc(N+[O-])c(OC(=O)C)c1

Structural features (general description):

• Aromatic ring: Monosubstituted benzoic acid core (benzenoid ring).
• Functional groups: One carboxylic acid (–CO2H) at C1; one nitro group (–NO2) at the para position relative to the acid (4-position); one acetoxy substituent (–O–C(=O)–CH3) at the meta position (3-position) relative to the acid.
• Connectivity (2D description): Starting from the benzoic acid carbonyl carbon as C1, positions: 1 = –CO2H, 3 = –O–C(=O)–CH3, 4 = –NO2; the remaining ring positions are unsubstituted hydrogens.
• Stereochemistry: None (achiral aromatic carboxylic acid); no stereocenters.

Notes:

• Any structure identifiers above labeled “literature” are provided for contextual reference. Consult the Certificate of Analysis (CoA) for lot-specific identifiers and confirmatory spectra (NMR/IR/MS) where applicable.

Synthetic Utility

Functional handles and their reactivity (literature/general):

• Carboxylic acid: Amenable to standard activation for amide or ester formation (EDC/Oxyma, HATU, DPPA/Curtius for isocyanates, CDI for anhydrides). Converting to acid chlorides ((COCl)2, SOCl2) enables acylations; formation of N-hydroxyphthalimide esters opens decarboxylative cross-couplings (Ni/photoredox) to install C–C, C–B, or C–S bonds.
• Acetoxy group: Serves as a phenolic protecting group; removal under basic or aminolytic conditions reveals the 3-hydroxy-4-nitrobenzoic acid for further derivatization (e.g., etherification or carbamate formation). Under strongly nucleophilic conditions, avoid transesterification or cleavage unless desired.
• Nitro group: Can be chemoselectively reduced to an aniline (4-amino), unlocking diazotization (Balz–Schiemann), Sandmeyer variants, or Buchwald–Hartwig couplings after appropriate activation. It also modulates ring electronics, discouraging electrophilic aromatic substitutions but potentially enabling SNAr on suitably activated positions.

Retrosynthetic value:

• Serves as a protected phenolic acid intermediate enabling orthogonal manipulations: undertake acid-coupling steps while temporarily masking the phenol, then deprotect late-stage.

Typical downstream transformations:

• Amide libraries via HATU/DIPEA in DMF.
• Decarboxylative borylation from RAE under Ni/photoredox to access aryl boronates.
• Selective nitro reduction with H2/Pd in EtOAc or EtOH, monitoring to preserve the acetoxy.

Adjust conditions to maintain acetoxy integrity when required.

Target Specificity

Not applicable. This product is a small-molecule research chemical, not a biological macromolecule or affinity reagent. No antigen/epitope, clone, isotype, or species reactivity data are relevant or provided for this item.