Molekula
3-Methyl-1-(4-sulfophenyl)-2-pyrazolin-5-one
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
3-Methyl-1-(4-sulfophenyl)-2-pyrazolin-5-one, also known as 4-(3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonic acid, is a pyrazolone sulfonic acid used as an organic building block and as an azo coupling component in the manufacture of yellow azo dyes. This chemical has a CAS number of 89-36-1, a molecular formula of C10H10N2O4S, and a molecular weight of 254.26 g/mol. It is stored at ambient conditions but requires careful handling due to its Danger classification. Molekula supplies 3-Methyl-1-(4-sulfophenyl)-2-pyrazolin-5-one from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
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25 g — £43.10 per pack ex VAT · £51.72 inc. VAT
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Specifications
| Property | Value |
|---|---|
| Appearance | Pale yellow powder |
| Solubility | Clear solution (in Na2CO3) |
| Assay (HPLC) | ≥99.0% |
| Insoluble Matter | ≤0.2% |
| Iron (Fe) | ≤0.002% |
| Lead (Pb) | ≤0.001% |
| Mercury (Hg) | ≤0.0001% |
| Arsenic (As) | ≤0.0001% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Transport Class | 8 |
| Packing Group | II |
| Acidity | Acid |
Identification
| Property | Value |
|---|---|
| SKU | 32793754 |
| CAS Number | 89-36-1 |
| IUPAC Name | 4-(3-methyl-5-oxo-4H-pyrazol-1-yl)benzenesulfonic acid |
| Molecular Formula | C10H10N2O4S |
| Molecular Weight | 254.26 |
| Exact Mass | 254.0361 |
| SMILES | CC1=NN(C(=O)C1)C2=CC=C(C=C2)S(=O)(=O)O |
| InChIKey | CWJQQASJVVAXKL-UHFFFAOYSA-N |
| InChI | InChI=1S/C10H10N2O4S/c1-7-6-10(13)12(11-7)8-2-4-9(5-3-8)17(14,15)16/h2-5H,6H2,1H3,(H,14,15,16) |
| PubChem CID | 66638 |
| UN Number | UN3261 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 2933199000 |
| Tariff Code | 2933199090 |
Safety & GHS
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Corrosive
GHS05
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Health Hazard
GHS07
Hazard statements
- H314 (sub cat. 1B) Causes severe skin burns and eye damage
- H317 May cause an allergic skin reaction
- H412 Harmful to aquatic life with long lasting effects
Precautionary statements
- P260 Do not breathe dust/fume/gas/mist/vapours/spray
- P273 Avoid release to the environment
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P303+361 IF ON SKIN (or hair): Remove immediately all contaminated clothing. Rinse with water/shower
- P304+340 IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
Documents
Safety Data Sheets (SDS)
Available in English, English (US), French, German, Italian, Portuguese, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- 1-(4-sulphophenyl) 3-methyl-2-pyrazolin-5-one
- 3-Methyl-1-(sulfophenyl)-2-pyrazolin-5-on
- 4-(3-Methyl-5-oxo-2-pyrazolin-1-yl)benzenesulphonic acid
- 4-(3-methyl-5-oxo-2-pyrazolinyl)benzenesulfonic acid
- 4-(3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl)benzene-1-sulfonic acid
- 4-(3-Methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonic acid
- 4-(3-methyl-5-oxo-4H-pyrazol-1-yl)benzenesulfonic acid
- 4-(3-methyl-5-oxo-4H-pyrazol-1-yl)benzenesulonic acid
- Benzenesulfonic acid, p-(3-methyl-5-oxo-2-pyrazolin-1-yl)-
- Pyrazoline G
Frequently asked questions
What is 3-Methyl-1-(4-sulfophenyl)-2-pyrazolin-5-one (CAS 89-36-1) commonly used for?
This compound is primarily used as a coupling agent in azo dye synthesis for textiles, leather, and paper, as well as in analytical chemistry for pH indicators and spectrophotometric assays.
What is the molecular formula and molecular weight of this product?
The molecular formula is C₁₀H₁₀N₂O₄S, and the molecular weight is 254.26 g/mol.
How should this chemical be stored?
Store at ambient temperature in a tightly sealed container, away from moisture and direct sunlight. Follow standard chemical storage practices for hazardous materials.
What purity grades are available for this product?
We supply this product in technical grade (95%+ purity) and analytical/pharmaceutical grade (98%+ purity). Let us know your specific application for recommendations.
Can Molekula supply this product in bulk quantities?
Yes, we offer bulk packaging options (e.g., 5 kg, 25 kg, and 100 kg drums) for industrial and commercial customers. Minimum order quantities may apply—contact us for details.
What documentation is provided with an order of this chemical?
Each order includes a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS/SDS), and batch-specific documentation for traceability. Custom packaging certificates are available upon request.
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Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.