24648-18-8

Upstream product

• 6289-46-9 dimethyl 2,5-dioxocyclohexane-1,4-dicarboxylate 
• 25186-39-4 2,5-Dichlor-3,6-dioxo-1,4-cyclohexadien-1,4-dicarbonsaeure-dimethylester 

Downstream Products

• 1065246-64-1 dimethyl 2,5-dichloro-3,6-diisopropoxyterephthalate 

Relevant academic research and scientific papers

Spectroscopic Studies of the Thermal Rearrangement Reaction of Dimethyl 3,6-Dichloro-2,5-dihydroxyterephthalate in the Solid State

The thermal rearrangement of the yellow (Y) isomer of dimethyl 3,6-dichloro-2,5-dihydroxyterephthalate in the solid state, which yields a white (W) isomer, has been investigated by a combination of Raman phonon spectroscopy and electronic emission spectro

Investigation of the polymorphs of dimethyl-3,6-dichloro-2,5-dihydroxyterephthalate by 13C solid-state NMR spectroscopy

Two of the three conformational polymorphs of dimethyl-3,6-dichloro-2,5-dihydroxyterephthalate are studied by solid-state NMR techniques. The structural differences between the polymorphs have previously been studied by X-ray. In these two polymorphs named white and yellow due to their color, the major structural difference is the torsional angle between the ester group and the aromatic ring. The yellow form has a dihedral angle of 4° between the plane of the aromatic ring and the plane of the ester group, while the white form has two different molecules per unit cell with dihedral angles of 70° and 85°. This change greatly affects the conjugation in the π-electronic system. In addition, there are differences in the hydrogen-bonding patterns, with the white form having intermolecular hydrogen bonds and the yellow form having intramolecular hydrogen bonds. In this work, the carbon isotropic chemical shift values and the chlorine electric field gradient (EFG) tensor information are extracted from the 13C MAS spectra, and the principal values of the chemical shift tensors of the carbons are obtained from 2D FIREMAT experiments. Quantum chemical calculations of the chemical shift tensor data as well as the EFG tensor are performed at the HF and DFT levels of theory on individual molecules and on stacks of three molecules to account for the important intermolecular interactions in the white form. The differences between the spectral data on the two polymorphs are discussed in terms of the known electronic and structural differences.

HIGH-AND LOW-POTENTIAL, WATER-SOLUBLE, ROBUST QUINONES

Substituted hydroquinones, 1,4-quinones, catechols, 1,2-quinones, anthraquinones, and anthrahydroquinones are disclosed herein. The substituted hydroquinones and catechols have the formula: while the substituted 1,4-quinones or 1,2-have the corresponding oxidized structure (1,4- benzoquinones and 1,2-benzoquinones). One or more of R1, R2, R3 and R4 include a sulfonate moiety, a sulfonimide moiety, or a phosphonate moiety, and any of R1, R2, R3 and R4 that do not include one of these moieties include an alkyl, a cycloalkyl, a thioether, a sulfoxide, a sulfone, a haloalkyl, a halogen, a nitrile, an imide, a pyrazole, or combinations thereof. The substituted anthraquinones have the formula: while the substituted anthrahydroquinones have the corresponding reduced structure. One or more of R1-R8 have a sulfonate or phosphate tethered to the ring by a thi other, amine, or ether including one or more alkyl groups. Any of R1-R8 that do not contain one of these moieties include an alkyl, a cycloalkyl, a thiother, a sulfoxide, a sulfone, a haloalkyl, a halogen, a hydroxyl, an alkoxyl, an ether, an amine, or hydrogen The substituted hydroquinones, 1,4-quinones, catechols, 1,2-quinones, anthraquinones, or anthrahydroquinones are soluble in water, stable in aqueous acid solutions, and have useful reduction potentials in the oxidized form. Accordingly, they can be used as redox mediators in emerging technologies, such as in mediated fuel cells or organic-mediator flow batteries.

2,5-Dihydroxyterephthalates, 2,5-dichloro-1,4-benzoquinone-3,6- dicarboxylates, and polymorphic 2,5-dichloro-3,6-dihydroxyterephthalates

Reaction of 2,5-dihydroxycyclohexa-1,4-diene-1,4-dicarboxylates with one equivalent of N-chlorosuccinimide cleanly gives 2,5-dihydroxyterephthalates; reaction with four equivalents of N-chlorosuccinimide gives 2,5-dichloro-l,4- benzoquinone-3,6-dicarboxylates instead. The latter compounds react with sodium dithionite to give 2,5-dichloro-3,6-dihydroxyterephthalates, which will find use in the study of polymorphic phase changes. Georg Thieme Verlag Stuttgart.