3349-15-3

Upstream product

• 527-53-7 1,2,3,5-Tetramethylbenzene 

Downstream Products

• 27021-17-6 3-bromo-2,4,5,6-tetramethyl-benzyl chloride 
• 6590-88-1 1-bromo-2,3,4,6-tetramethyl-5-nitro-benzene 
• 4674-21-9 4,6-dibromo-1,2,3,5-tetramethylbenzene 
• 4681-79-2 2,3,4,5-tetramethylbenzene-1-sulfonic acid 
• 671788-60-6 3-bromo-2,4,5,6-tetramethyl-benzyl iodide 
• 16372-48-8 2,3,4,6-tetramethylbenzoyl chloride 
• 16372-55-7 2,3,4,6,2',3',4',6'-octamethyl-benzophenone 
• 16372-61-5 2,3,4,6,2',3',4',6'-Octamethyl-benzhydrol 
• 54509-72-7 2-iodo-1,3,4,5-tetramethylbenzene 
• 2408-38-0 2,3,4,6-tetramethylbenzoic acid 

Relevant academic research and scientific papers

Selective Nuclear Halogenation of Polymethylbenzenes with Alumina-Supported Copper(II) Halides

The halogenation of polymethylbenzenes with alumina-supported copper(II) halides under heterogeneous conditions in nonpolar solvents gave nuclear-halogenated compounds selectively in high yields; no side-chain-halogenated compounds were formed.

ETUDE CINETIQUE DE LA REACTION DE BROMINATION DANS LE SO2 LIQUIDE. REACTIVITES DU BENZENE, DES POLYMETHYLBENZENES ET D'ANISOLES SUBSTITUES. DETERMINATION DES REACTIVITES RELATIVES ET CALCUL DES FACTEURS DE VITESSE PARTIELLE

Absolute rate constants for the bromination of a series of anisoles and polymethylbenzenes, have been measured in liquid sulfur dioxide at -23 +/- 2 deg C.Rate constants for benzene and toluene were determined by extrapolation as: 9.6E-7 and 4.2E-4 l mol-1 mn-1 respectively.Under these conditions, the bromination of anisole provides 0.56percent ortho- and 98.99percent para-bromoanisole, and the rate relative to benzene is 6.98E8/1.00.These date lead to the partial rate factors for the methoxy group: οOMef = 1.1E7 and pOMef = 4.12E9.The value mOMef = 1.4 is calculated from the rate constant for p-dimethoxy benzene, 10 l mol-1 mn-1.Similarly, in the case of bromination of toluene, a relative rate of 443/1.00, and an isomer distribution of 16percent ortho- and 84percent para, permit the calculation of partial rate for the methyl group:οMef = 212 mMef = 6.4 pMef = 2232 > correlations log k = f(Σ?+), established for the bromination of anisoles and polymethylbenzenes, exhibit large values for their slopes (ρAnisoles+ = -10.51; ρ+polymethylbenzenes = -9.5), and indicate satisfactory additivity of substituent effects.It appears that the + M effect of the methoxy group is less strong in this solvent than it is in water or acetic acid.Despite its low dielectric constant, (D = 17.5 at -20 deg C), liquid sulfur dioxide appearars to be quite a favourable medium for electrophilic aromatic substitution.Thus, for identical experimental conditions, the rate constants for bromination are 1E2 to 1E4 lower than those observed in water, but 1E3 to 1E5 larger than those in acetic acid.