3453-84-7

Basic information

• Product Name: PSEUDOCUMENE-5-SULFONIC ACID
• Synonyms: pseudocumene-5-sulfonicacid;2,4,5-TRIMETHYLBENZENSULFONIC ACID;2,4,5-TRIMETHYLBENZENESULFONIC ACID;1,2,4-Trimethyl-5-benzenesulfonic acid;Benzenesulfonic acid, 2,4,5-triMethyl-;NSC 163978
• CAS NO: 3453-84-7
• Molecular Formula: C₉H₁₂O₃S
• Molecular Weight: 200.257
• EINECS: 200-258-5
• Mol File: 3453-84-7.mol
• Article Data: 4

Chemical Properties

• Melting Point: 110.5-112℃
• Appearance: /
• Density: 1.243
• Refractive Index: 1.545
• Storage Temp.: 2-8°C
• CAS DataBase Reference: PSEUDOCUMENE-5-SULFONIC ACID(CAS DataBase Reference)
• NIST Chemistry Reference: PSEUDOCUMENE-5-SULFONIC ACID(3453-84-7)
• EPA Substance Registry System: PSEUDOCUMENE-5-SULFONIC ACID(3453-84-7)

Safety Data

• Hazard Codes: C
• Statements: 34
• Safety Statements: 26-27-36/37/39-45
• Hazardous Substances Data: 3453-84-7(Hazardous Substances Data)

Usage

Chemical Properties

White or light yellow crystalline powder

InChI:InChI=1/C9H12O3S/c1-6-4-8(3)9(5-7(6)2)13(10,11)12/h4-5H,1-3H3,(H,10,11,12)

Upstream product

• 95-63-6 1,2,4-Trimethylbenzene 
• 7664-93-9 sulfuric acid 
• 4681-78-1 2,3,5,6-tetramethylbenzene-1-sulfonic acid 
• 52890-52-5 2,4,5-trimethylbenzophenone 

Downstream Products

• 7664-93-9 sulfuric acid 
• 5469-19-2 1-bromo-2,4,5-trimethylbenzene 
• 51307-74-5 5-sulfonyl-1,2,4-benzenetricarboxylic acid 
• 17851-27-3 1-ethyl-2,4,5-trimethylbenzene 
• 13059-46-6 2,4,5-trimethyl-3,6-dinitro-benzenesulfonic acid 
• 58138-52-6 2-hydroxy-4,5-dimethylbenzoic acid 
• 95-63-6 1,2,4-Trimethylbenzene 
• 13250-07-2 phenyl-(2,4,5-trimethyl-phenyl)-sulfone 
• 92890-80-7 2,4,5-trimethylsulphonyl chloride 
• 4961-03-9 5-hydroxy-1,2,4-benzenetricarboxylic acid 
• 82940-81-6 3-bromo-2,4,5-trimethylbenzenesulfonic acid 
• 496-78-6 2,4,5-trimethylphenol 
• 95111-55-0 2,5-dibromo-3,4,6-trimethyl-phenol 
• 15460-08-9 2-bromo-3,4,6-trimethyl-phenol 

Relevant articles and documents

Aromatic isomerization and related reactions. Part 61. Reactions of the tetra- and pentamethylbenzenesulfonic acids and hexamethylbenzene in concentrated sulfuric acid; the mechanism of the Jacobsen reaction

The chemical behaviour of the sulfonic acids of pentamethylbenzene (PMB) and the three tetramethylbenzenes (TeMB's( in concentrated aqueous sulphuric acid has been studied quantitatively using 1H AND 13C NMR and UV spectroscopy.PMB-sulfonic acid yields (protonated) hexamethylbenzene (HMB) and the 2,3,4,5- and 2,3,4,6-TeMB-1-sulfonic acids in an initial ratio of 9/1/8 up to a substrate conversion of 36percent; the ratio of HMB to the TeMB-1-sulfonic acids remains 1/1 and the only subsequent reaction is the relatively slow conversion of the 2,3,4,6- into the 2,3,4,5-TeMB-1-sulfonic acid which is the only stable TeMB-1-sulfonic acid isomer in concentrated sulfuric acid. 2,3,5,6-TeMB-1-sulfonic acid yields, as initial products, 2,3,5- and 2,4,5-trimethylbenzene(TrMB)-1-sulfonic acid together with PMB-1-sulfonic acid in a ratio of ca. 1/3/4.The subsequent products are the 2,3,4,6- and 2,3,4,5-TeMB-1-sulfonic acids, of which the former slowly isomerizes to the latter, together with some HMB. 2,3,4,6-TeMB-1-sulfonic acid yields the stable 2,3,4,5-isomer.It is proposed that the conversion proceeds via inter-molecular trans-methylations involving 1,3,5-TrMB and PMB as intermediates, the concentrations of which, however, are below the limits of NMR detection.Based on (i) the desulfonation-sulfonation equilibrium data of the TrMB-, TeMB- and PMB-sulfonic acids, (ii) the strong rate decrease for the conversion of both 2,3,4,6- and 2,3,5,6-TeMB-1-sulfonic acid in 98.4percent H2SO4 in the presence of added cyclohexane and (iii) the very strong electron-withdrawing and meta-directing effect of the SO3-/SO3H substituent, it is proposed that all the conversions proceed inter-molecularly, that the trans-methylating reagent is the polymethylbenzene (and not the corresponding sulfonate) and that the substrate undergoing methylation is most likely to be once again the polymethylbenzene rather than its sulfonate ion.

Synthesis, structure and proton conductivity of 2,4,5-trimethylbenzenesulfonic acid dihydrate

2,4,5-Trimethylbenzenesulfonic acid dihydrate was isolated in the monocrystalline state. Crystal and molecular structures of the compound were determined by X-ray diffraction analysis and vibrational spectroscopy. The compound crystal system is monoclinic