89280-34-2

Basic information

• Product Name: 1H-Pyrazole-4-sulfonic acid, 3,5-dimethyl-
• Synonyms: 1H-Pyrazole-4-sulfonic acid,3,5-dimethyl;3,5-Dimethyl-4-pyrazolesulfonic acid;3,5-Dimethyl-1H-pyrazol-4-sulfonsaeure;3,5-dimethylpyrazole-4-sulfonic acid
• CAS NO: 89280-34-2
• Molecular Formula: C5H8N2O3S
• Molecular Weight: 176.196
• Mol File: 89280-34-2.mol
• Article Data: 1

Chemical Properties

• Density: 1.514±0.06 g/cm3(Predicted)
• CAS DataBase Reference: 1H-Pyrazole-4-sulfonic acid, 3,5-dimethyl-(CAS DataBase Reference)
• NIST Chemistry Reference: 1H-Pyrazole-4-sulfonic acid, 3,5-dimethyl-(89280-34-2)
• EPA Substance Registry System: 1H-Pyrazole-4-sulfonic acid, 3,5-dimethyl-(89280-34-2)

Safety Data

• Hazardous Substances Data: 89280-34-2(Hazardous Substances Data)

Usage

Structure

A derivative of pyrazole (a five-membered aromatic ring with two nitrogen atoms) with a sulfonic acid group and two methyl groups attached to the 3 and 5 positions.

Usage

Commonly used as a building block in organic synthesis, particularly in the production of pharmaceuticals and agrochemicals.

Acidity

Strong acid due to the presence of the sulfonic acid group.

Applications

Useful intermediate for the preparation of dyes, pigments, and other organic compounds.

Analytical chemistry

Serves as a reagent for the determination of certain metal ions in solution.

Upstream product

• 67-51-6 3,5-dimethyl-1H-pyrazole 
• 108-24-7 acetic anhydride 

Relevant articles and documents

3,5-Dimethylpyrazole promoted sulfonation of acetic anhydride by H 2SO4 to sulfoacetic acid and methanedisulfonic acid, and crystal structures of the complexes with Co2+, Zn2+, Ba2+, Pb2+ and Cs+

Sulfuric acid can sulfonate acetic anhydride (but not acetic acid) to sulfoacetic acid, and also to methanedisulfonic acid in the presence of 3,5-dimethylpyrazole. Under the experimental conditions employed, sulfonation of 3,5-dimethylpyrazole with concentrated sulfuric acid in acetic anhydride/acetic acid as solvent leads to a mixture of approximately 47 mol% 3,5-dimethylpyrazole-4-sulfonic acid, 34 mol% sulfoacetic acid and 19 mol% methanedisulfonic acid, as determined by 1H NMR spectroscopy. The Co2+, Zn2+, Ba2+ and Pb2+ complexes of the sulfoacetate ligand, as well as the Cs+ complex of the methanedisulfonate ligand were isolated upon crystallization of the compounds obtained from the reaction of the above ligand mixture with the corresponding metal oxide or carbonate in water. Single-crystal X-ray crystallography of Co(O3SCH2CO2)(H2O)3, Zn(O3SCH2CO2)(H2O)3, Ba(O3SCH2CO2)(H2O), Pb(O 3SCH2CO2)(H2O) and Cs 2(O3SCH2SO3) reveals a variety of new coordination modes of the two sulfonated ligands within those structures.