Catechol carbonate

This enzyme [EC 1.14.12.1], also known as anthranilate hydroxylase, decarboxylating, catalyzes the reaction of anthranilate with NAD(P)H, dioxygen, and two water molecules to produce catechol, carbon dioxide, NAD(P)+, and ammonia. The enzyme requires an iron ion as a cofactor. 

Benzoate 1,2-dioxygenase [EC 1.14.12.10], also called benzoate hydroxylase, catalyzes the reaction of benzoate with dioxygen and NADH to generate catechol, carbon dioxide, and NAD+. This is a multiprotein system which contains a reductase which is an iron-sulfur flavoprotein (FAD) and an iron-sulfur oxygenase. 

The metabolism of aryldioxymethylene compounds to catechol, carbon monoxide and formic acid is consistent with hydroxylation of the carbene complex (Scheme 3) [5],... 

Besides VC, vinyl ethylene carbonate (VEC), phenylethylene carbonate (PhEC), ° phenylvinylene carbonate (PhVC), catechol carbonate (CC), - ally methyl carbonate (AMC), - allyl ethyl carbonate (AEC), vinyl acetate (VA), and other vinyl compounds, - - acryronitrile (AAN) - and 2-cyanofuran (CN-F), whose chemical structures are given in Fig. 4.10, showed the similar effect and no graphite exfoliation in PC solvent systems. 

Catechol Carbonate Ethylene Sulfite Propylene Sulfite... 

Wang C, Nakamura H, Komatsu H, Noguchi H, Yoshio M, Yoshitake H (1998) Suppression of electrochemical decomposition of propylene carbonate (PC) on a graphite anode in PC base electrolyte with catechol carbonate. DenM Kagaku oyobi Kogyo Butsuri Kagaku 66 286-292... 

Other Methods. A variety of other methods have been studied, including phenol hydroxylation by N2O with HZSM-5 as catalyst (69), selective access to resorcinol from 5-methyloxohexanoate in the presence of Pd/C (70), cyclotrimerization of carbon monoxide and ethylene to form hydroquinone in the presence of rhodium catalysts (71), the electrochemical oxidation of benzene to hydroquinone and -benzoquinone (72), the air oxidation of phenol to catechol in the presence of a stoichiometric CuCl and Cu(0) catalyst (73), and the isomerization of dihydroxybenzenes on HZSM-5 catalysts (74). 

The properties of 1,1-dichloroethane are Hsted ia Table 1. 1,1-Dichloroethane decomposes at 356—453°C by a homogeneous first-order dehydrochlofination, giving vinyl chloride and hydrogen chloride (1,2). Dehydrochlofination can also occur on activated alumina (3,4), magnesium sulfate, or potassium carbonate (5). Dehydrochlofination ia the presence of anhydrous aluminum chloride (6) proceeds readily. The 48-h accelerated oxidation test with 1,1-dichloroethane at reflux temperatures gives a 0.025% yield of hydrogen chloride as compared to 0.4% HCl for trichloroethylene and 0.6% HCl for tetrachloroethylene. Reaction with an amine gives low yields of chloride ion and the dimer 2,3-dichlorobutane, CH CHCICHCICH. 2-Methyl-l,3-dioxaindan [14046-39-0] can be prepared by a reaction of catechol [120-80-9] with 1,1-dichloroethane (7). 

Catechols can be protected as diethers or diesters by methods that have been described to protect phenols. However, formation of cyclic acetals and ketals (e.g., methylenedioxy, acetonide, cyclohexylidenedioxy, diphenylmethylenedioxy derivatives) or cyclic esters (e.g., borates or carbonates) selectively protects the two adjacent hydroxyl groups in the presence of isolated phenol groups. 

Cyclic carbonates have been used to a limited extent only (since they are readily hydrolyzed) to protect the catechol group in a polyhydroxy benzene. 

Polycarbonates were first prepared by Einhom in 1898 by reacting the dihydroxybenzenes, hydroquinone and resorcinol, separately with phosgene in solution in pyridine. The hydroquinone polycarbonate was an infusible and insoluble crystalline power whereas the resorcinol polymer was an amorphous material melting at about 200°C. The third dihydroxybenzene, catechol, yields a cyclic carbonate only, which is not surprising bearing in mind the proximity of... 

Using cesium carbonate in methanol, Kellogg and coworkers were able to convert catechol and pentaethylene glycol into benzo-18-crown-6 in 74% yield. They found that the cesium salts in these reactions were usually equal or superior to the potassium salts. 

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