Description

5-Nitro-o-toluenesulfonic acid (CAS No. 121-03-9) is a high-purity sulfonic acid derivative with the molecular formula C₇H₇NO₅S. This compound, also known by its IUPAC name 2-methyl-5-nitrobenzenesulfonic acid, is a versatile organic intermediate widely used in chemical synthesis and industrial applications. Its structure features a nitro group and a sulfonic acid group on a toluene backbone, making it valuable for electrophilic substitution reactions and as a precursor for dyes, pharmaceuticals, and agrochemicals.

Our product is rigorously tested for purity, stability, and consistency, ensuring optimal performance in research and manufacturing processes. It is supplied as a fine crystalline powder with excellent solubility in polar solvents such as water, ethanol, and dimethyl sulfoxide (DMSO). Proper storage in a cool, dry place is recommended to maintain its integrity.

Applications include use as a sulfonating agent, catalyst, or intermediate in organic synthesis. Suitable for researchers and industrial chemists seeking reliable and high-quality reagents for advanced chemical transformations.

Properties

• CAS Number: 121-03-9
• Complexity: 314
• IUPAC Name: 2-methyl-5-nitro-benzenesulfonic acid
• InChI: InChI=1S/C7H7NO5S/c1-5-2-3-6(8(9)10)4-7(5)14(11,12)13/h2-4H,1H3,(H,11,12,13)
• InChI Key: ZDTXQHVBLWYPHS-UHFFFAOYSA-N
• Exact Mass: 217.00449350
• Molecular Formula: C7H7NO5S
• Molecular Weight: 217.20
• SMILES: CC1=C(C=C(C=C1)[N+](=O)[O-])S(=O)(=O)O
• Topological: 109
• Monoisotopic Mass: 217.00449350
• Physical Description: Water or Solvent Wet Solid; Dry Powder
• Color/Form: PRISMS OR PLATES FROM WATER
• Melting Point: 133.5 °C
• Flash Point: Flash point > 133 °C
• Solubility: VERY SOL IN WATER, ALCOHOL, ETHER, CHLOROFORM
• Synonyms: 2-METHYL-5-NITROBENZENESULFONIC ACID, 121-03-9, 4-Nitrotoluene-2-sulfonic acid, p-Nitrotoluene-o-sulfonic acid, 5-Nitro-o-toluenesulfonic acid, Pntos, 4-Nitro-2-toluenesulfonic acid, 5-Nitro-2-methylbenzenesulfonic acid, o-Toluenesulfonic acid, 5-nitro-, Kyselina 4-nitrotoluen-2-sulfonova, NSC 9580, JBO1Z0PMOH, UNII-JBO1Z0PMOH, HSDB 5470, 2-Toluenesulfonic acid, 5-nitro, EINECS 204-445-3, p-nitrotoluol-o-sulfonic acid, BRN 2216176, p-nitrotoluene-o-sulphonic acid, 5-nitro-o-toluenesulphonic acid, 4-mitro-2-toluenesulphonic acid, DTXSID4026975, CHEBI:67120, NSC-9580, 2-methyl-5-nitrobenzenesulphonic acid, 5-nitro-2-methylbenzenesulphonic acid, DTXCID506975, EC 204-445-3, 3-11-00-00173 (Beilstein Handbook Reference), 2-TOLUENESULFONIC ACID, 5-NITRO-, 204-445-3, 4-Nitrotoluene-2-sulphonic acid, Benzenesulfonic acid, 2-methyl-5-nitro-, 4-Nitrotoluene-2-sulfonic Acid Hydrate, 5-Nitro-o-toluenesulfonic acid; NSC 9580; PNTOS, CAS-121-03-9, Kyselina 4-nitrotoluen-2-sulfonova [Czech], p-Nitrotoluolsulfosaure, 2-methyl-5-nitrobenzene-1-sulfonic acid, WLN: WSQR B1 ENW, p-Nitrotoluene-o-sulfonicacid, SCHEMBL709336, SCHEMBL9322217, p-nitrotoluene-2-sulphonic acid, CHEMBL3183957, ZDTXQHVBLWYPHS-UHFFFAOYSA-, NSC9580, CS-M3300, Tox21_202190, Tox21_303151, SBB056747, AKOS003241755, NCGC00249182-01, NCGC00257106-01, NCGC00259739-01, BS-22427, 4-nitrotoluene-2-sulfonic acid, AldrichCPR, DB-041599, N0277, NS00003565, ST50981581, 2-METHYL-5-NITROBENZENESULFONIC ACID [HSDB], Q27135631, 4-Nitrotoluene-2-sulfonic acid 10 microg/mL in Acetonitrile, InChI=1/C7H7NO5S/c1-5-2-3-6(8(9)10)4-7(5)14(11,12)13/h2-4H,1H3,(H,11,12,13)

Application

5-Nitro-o-toluenesulfonic acid is primarily used as a key intermediate in the synthesis of dyes, pigments, and pharmaceuticals due to its reactive nitro and sulfonic acid functional groups. It serves as a sulfonating agent in organic reactions and can act as a catalyst or co-catalyst in esterification and condensation processes. Researchers also utilize this compound in the development of specialty chemicals and agrochemicals, leveraging its electrophilic properties for functionalization of aromatic systems.

Safety and Hazards

GHS Hazard Statements

• H302: Harmful if swallowed [Warning Acute toxicity, oral]
• H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]
• H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

Precautionary Statements

• P260, P264, P264+P265, P270, P280, P301+P317, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P321, P330, P363, P405, and P501

Hazard Classes and Categories

• Acute Tox. 4 (80.1%)
• Skin Corr. 1B (19%)
• Skin Irrit. 2 (81%)
• Skin Sens. 1B (80.1%)
• Eye Dam. 1 (80.5%)

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