158669-22-8

Upstream product

• 39021-83-5 3,6-dimethoxy-o-xylene 
• 526-86-3 2,3-dimethyl-1,4-benzoquinone 
• 864514-96-5 2-chloro-5,6-dimethyl-4-methoxyphenol 
• 77-78-1 dimethyl sulfate 

Downstream Products

• 717122-46-8 N-[(6-chloro-2,5-dimethoxy-3,4-dimethylphenyl)methyl]-2,2,2-trifluoroacetamide 
• 864515-08-2 3-chloro-5,6-dimethyl-2-{[(2,2,2-trifluoroacetyl)amino]methyl}-2,5-cyclohexadiene-1,4-dione 

Relevant academic research and scientific papers

Cation Radicals as Intermediates in Aromatic Halogenation with Iodine Monochloride: Solvent and Salt Effects on the Competition between Chlorination and Iodination

Three distinct classes of substitutional reactivity can be discerned in the halogenation of a series of methyl-substituted methoxybenzenes (ArH) with iodine monochloride (ICl), namely, exclusive iodination, exclusive chlorination, and mixed iodination/chlorination.Spectral studies establish the prior formation of the charge-transfer complex which suffers electron transfer to afford the reactive triad .+,I.,Cl(-)> according to Scheme 1.Separate reactivity studies show that chlorination and iodination can result from the quenching of the aromatic cation radical by chloride and iodine (atom), respectively.Iodination versus chlorination thus represents the competition between radical-pair and ion-pair collapse from the reactive triad, and it is predictably modulated by solvent polarity and added salt.

A general synthesis of quinone ammonium salts

A three-step procedure has been developed to convert substituted p-dimethoxybenzenes to quinone ammonium salts. Five examples of quinone ammonium salts have been prepared with this procedure. In the first step, the aromatic species is reacted with N-(hydr

Radical cation mechanism of aromatic halogenation by halogens or iodine chloride in 1,1,1,3,3,3-hexafluoropropan-2-ol

The reaction between aromatic compounds ArH and halogenating agents, viz. iodine chloride, chlorine, bromine, iodine, N-bromosuccinimide and N-chlorosuccinimide, in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFP) has been investigated. EPR spectroscopy established that these reagents produced persistent radical cations ArH.+ from ArH with Erev(ArH.+/ArH) up to 1.6, 1.3, 1.4, 1.1, 1.5 and 1.2 V vs. Ag/AgCl, respectively. Cyclic voltammetry of the halogenating species shows that no effect of complexation with halide ion is observed in HFP, as expected from its capacity to drastically attenuate nucleophilic reactivity, and that the cathodic peak potentials Epc (referenced to the internal ferricinium/ferrocene redox couple) are significantly or remarkably higher in HFP than in acetonitrile. For N-bromosuccinimide, the difference amounts to almost 1 V. The persistency of the radical cations in HFP is such that the kinetics of reactions between a halogenating agent, such as iodine chloride or bromine, and ArH, such as 1,4-dimethoxybenzene [Erev(ArH.+/ArH) = 1.50 V vs. Ag/AgCl] or 1,4-dimethoxy-2,3-dimethylbenzene [Erev(ArH.+/ArH) = 1.16 V], have been studied at room temperature over periods of hours. The initial concentration of the radical cation corresponds to yields in the range of 40-100%, depending on the reaction conditions. It is thus possible to establish that the radical cation decays via two pathways, one being the well known oxidative substitution reaction with halide ion. The second mechanism involves halogen atom transfer from the halogenating agent (Cl atom from ICl, Br atom from bromine). In the case of the radical cation of 1,4-dimethoxy-2,3-dimethylbenzene reacting with bromide ion or bromine, the latter reaction is >102 times faster.