4-Oxo-8-propyl-4H-pyrano[3,2-b]pyran-2-carboxylic Acid 1945950-21-9 98% Yellow to Orange Solid API Intermediate / Pharmaceutical Building Block

1. Product Overview

4-Oxo-8-propyl-4H-pyrano[3,2-b]pyran-2-carboxylic Acid (CAS 1945950-21-9) is a fused bicyclic pyran-4-one derivative bearing a propyl side chain at the 8-position and a carboxylic acid moiety at the 2-position. This unique scaffold belongs to the pyrano[3,2-b]pyran class of oxygen-containing heterocycles, which are recognized for their diverse biological activities, including anti-inflammatory, antimicrobial, and anticancer properties. The presence of the enone system (α,β-unsaturated ketone) and the carboxylic acid provides multiple handles for further derivatization, making it a valuable intermediate in pharmaceutical synthesis and medicinal chemistry.

2. Key Features and Benefits

• Dual Reactive Sites: The carboxylic acid at C-2 enables amide/ester coupling, while the C-4 carbonyl participates in nucleophilic addition or reduction reactions, allowing for versatile structural elaboration.

• Electron-Deficient Enone System: The α,β-unsaturated ketone moiety is susceptible to Michael addition with thiols, amines, or enolates, facilitating the construction of complex molecular architectures.

• Lipophilic Side Chain: The 8-propyl substituent enhances membrane permeability (predicted LogP ~2.8) and modulates the electronic properties of the bicyclic core.

• High Purity: Supplied at ≥98% (HPLC), ensuring minimal impurities for sensitive pharmaceutical applications.

• Stable Solid Form: Yellow to orange crystalline solid with good storage stability under recommended conditions.

3. Major Applications

• Pharmaceutical Intermediate: Used in the synthesis of drug candidates targeting inflammatory diseases, cancer, and infectious diseases, leveraging the pyranopyran core's known bioactivity.

• Medicinal Chemistry: Serves as a scaffold for structure-activity relationship (SAR) studies, particularly in the development of novel anti-inflammatory agents and kinase inhibitors.

• Natural Product Synthesis: The pyrano[3,2-b]pyran skeleton is found in various bioactive natural products; this compound can serve as a starting material for total synthesis or analog preparation.

• Materials Science: The conjugated enone system may find applications in organic electronics or as a building block for functional dyes and fluorescent probes.

4. Technical Specifications

Item Description
Product Name 4-Oxo-8-propyl-4H-pyrano[3,2-b]pyran-2-carboxylic Acid
Synonyms 8-Propyl-4-oxo-4H-pyrano[3,2-b]pyran-2-carboxylic acid; 4-Oxo-8-propylpyrano[3,2-b]pyran-2-carboxylic acid
CAS Number 1945950-21-9
Molecular Formula C₁₂H₁₂O₅
Molecular Weight 236.22 g/mol
MDL Number MFCD29907174
Assay (Purity) ≥98% (HPLC)
Appearance Yellow to orange crystalline solid or powder
Melting Point ~180–210 °C (decomposes, predicted based on analogous pyran-4-ones)
Boiling Point ~398.5 °C (Predicted)
Density ~1.35 g/cm³ (Predicted)
pKa (Carboxylic Acid) ~3.5 ± 0.3 (Predicted)
Calculated LogP ~2.8
Polar Surface Area (PSA) ~76.7 Ų
Solubility Soluble: DMSO (>50 mg/mL), DMF, Methanol (slightly), Ethanol (slightly).
Slightly Soluble:Acetone, THF, Acetonitrile.
Practically Insoluble:Water (free acid form); soluble as sodium/potassium salt in aqueous buffer.
Spectral Data (Predicted) ¹H NMR (DMSO‑d₆): δ 0.95 (t, J≈7.3 Hz, 3H, CH₃), 1.65 (sextet, J≈7.3 Hz, 2H, CH₂), 2.60 (t, J≈7.3 Hz, 2H, CH₂), 6.35 (s, 1H, ArH), 7.80 (s, 1H, ArH), 12.5 (br s, 1H, COOH).
¹³C NMR (DMSO‑d₆):δ 13.5 (CH₃), 22.5 (CH₂), 35.0 (CH₂), 110–165 (aromatic/olefinic), 165.5 (COOH), 180.0 (C=O, pyran-4-one).
SMILES CCCC1=CC(=O)OC2=C(C(=O)O)C=CC(=O)O12
InChI Key QVDEMJETIGJXLV-UHFFFAOYSA-N
Storage (Powder) 2–8 °C, sealed, protected from light and moisture; stable ≥18–24 months
Solution Stability DMSO stocks stable at -20°C for 1–3 months; avoid repeated freeze-thaw
HS Code 2932.99.90

5. Storage and Handling

• Storage: Store in a tightly sealed container at 2–8 °C, protected from light and moisture. For long-term storage (>12 months), a desiccator is recommended. The enone system is stable under these conditions but may be sensitive to strong nucleophiles or prolonged exposure to high humidity.

• Handling: Allow vial to reach room temperature before opening to prevent condensation. Dissolve in anhydrous DMSO, DMF, or MeOH as required. For aqueous work, the carboxylic acid can be neutralized with dilute NaOH or KHCO₃ to form a water-soluble salt.

• Solution Preparation: Prepare stock solutions in anhydrous DMSO (10–50 mM). The compound may require gentle warming (≤50 °C) and sonication for complete dissolution. Protect from light.

• Freeze-Thaw: Aliquot DMSO stocks upon preparation. Minimize freeze-thaw cycles; discard any precipitated or discolored solution.

6. Safety Summary (Full SDS Highlights)

• GHS Classification: GHS07 – Warning

• Signal Word: Warning

• Hazard Statements:

• H302: Harmful if swallowed.

• H315: Causes skin irritation.

• H319: Causes serious eye irritation.

• H335: May cause respiratory irritation.

• Precautionary Statements:

• P261: Avoid breathing dust/mist/vapors. Use only in a well-ventilated area or fume hood.

• P264: Wash hands, forearms, and face thoroughly after handling.

• P270: Do not eat, drink, or smoke in areas where this material is used.

• P271: Use only outdoors or in a well-ventilated area.

• P280: Wear protective gloves (nitrile), safety glasses with side shields, and lab coat.

• P301+P312: IF SWALLOWED: Call a POISON CENTER or physician if you feel unwell.

• P302+P352: IF ON SKIN: Wash with plenty of soap and water.

• P304+P340: IF INHALED: Remove person to fresh air and keep comfortable for breathing.

• P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing.

• P330: Rinse mouth if swallowed.

• P337+P313: If eye irritation persists: Get medical advice/attention.

• P403+P233: Store in a well-ventilated place. Keep container tightly closed.

• P501: Dispose of contents/container in accordance with local, regional, and national regulations.

• First Aid Measures:

• Inhalation: Remove to fresh air. If breathing difficult, administer oxygen and seek medical attention.

• Skin Contact: Immediately wash with plenty of soap and water. Remove contaminated clothing. Seek medical advice if irritation or rash develops.

• Eye Contact: Flush immediately with copious lukewarm water for at least 15 minutes. Remove contact lenses if possible. Seek medical attention.

• Ingestion: Rinse mouth. Do NOT induce vomiting. Give water to drink if conscious. Seek medical advice.

• Fire-Fighting Measures:

• Suitable Extinguishing Media: Water spray, alcohol-resistant foam, dry chemical, or CO₂.

• Special Hazards: Combustion may produce irritating/acrid smoke (CO, CO₂).

• Protective Equipment: Wear self-contained breathing apparatus (SCBA) and full protective clothing.

• Spill Response:

• Avoid dust generation. Sweep up and place in a suitable closed container for disposal. Do not allow entry to drains or waterways. Ventilate area after cleanup.

• Handling & Storage:

• Handle in fume hood. Keep container closed when not in use. Store cool (2–8 °C), dry, and away from strong oxidizers and strong bases.

• Intended Use: For laboratory research and development ONLY. Not for human or veterinary therapeutic, diagnostic, or food use.

Pls input...