Cupric Chloride Oxide

The direct oxidation of ethylene is used to produce acetaldehyde (qv) ia the Wacker-Hoechst process. The catalyst system is an aqueous solution of palladium chloride and cupric chloride. Under appropriate conditions an olefin can be oxidized to form an unsaturated aldehyde such as the production of acroleia [107-02-8] from propjiene (see Acrolein and derivatives). 

Cupric chloride or copper(II) chloride [7447-39 ], CUCI2, is usually prepared by dehydration of the dihydrate at 120°C. The anhydrous product is a dehquescent, monoclinic yellow crystal that forms the blue-green orthohombic, bipyramidal dihydrate in moist air. Both products are available commercially. The dihydrate can be prepared by reaction of copper carbonate, hydroxide, or oxide and hydrochloric acid followed by crystallization. The commercial preparation uses a tower packed with copper. An aqueous solution of copper(II) chloride is circulated through the tower and chlorine gas is sparged into the bottom of the tower to effect oxidation of the copper metal. Hydrochloric acid or hydrogen chloride is used to prevent hydrolysis of the copper(II) (11,12). Copper(II) chloride is very soluble in water and soluble in methanol, ethanol, and acetone. 

Cupri-. cupric, copper(II). -azetst, n. cupric acetate, copper(II) acetate, -carbonat, n. cupric carbonate, copper(II) carbonate, -chlorid, n. cupric chloride, copper(II) chloride. -hydroxyd, n. cupric hydroxide, cop-per(II) hydroxide. -ion, n. cupric ion, copper(II) ion. -ozalat, n. cupric oxalate, copper(II) oxalate, -oxyd, n. cupric oxide, copper(II) oxide. -salz, n. cupric salt, copper(II) salt, -suifat, n. cupric sulfate. copper(II) sulfate, -sulfid, n. cupric sulfide, copper(II) sulfide, -verbihdung, /. cupric compound, copper(II) compound, -wein-saure, /. cupritartaric acid. 

The hydrolytic step (Part D) uses conditions described by Narasaka, Sakashita, and Mukaiyama.11 It was necessary to modify the original stoichiometry, since the recommended molar ratio of substrate cupric chloride cupric oxide (1 2 4) gave only a 57% yield of 3-bcnzoylindole. 

Instead of copper one can use zinc, iron, stannous chloride, or cuprous chloride, the last-named two being oxidized to stannic and cupric chloride respectively. The reactions are carried out at low temperature ( — 10 to — 20°C) in acetone or ethyl acetate (Nesmeyanov et al., 1934 a). 

The oxidative dimerization of the anion of methyl phenyl sulfone (from a Grignard reagent) in ethereal solution in the presence of cupric chloride in 5% yield has been reported47. Despite the reported48 poor stability of the a-sulfonyl C-centered radicals, Julia and coworkers49 provoked the dimerization (in 13 to 56% yields) of the lithiated carbanion of alkyl phenyl sulfones using cupric salts as oxidants. The best results are obtained with cupric triflates in THF-isobutyronitrile medium (56% yield for R = H). For allyl phenyl sulfones the coupling in the 3-3 mode is predominant. 

The process can be operated under moderate conditions (50-130 °C and 3-10 bar) in a single reactor. Regeneration of cupric chloride occurs in a separate oxidizer. 

The reaction shows a first-order dependence on substrate concentration but, except at very low concentration, is zero-order with respect to oxidant moreover, the zero-order rate coefficient is the same as that observed with oxidations by iodine, cupric chloride and silver nitrate. The reaction is acid-catalysed. The oxidation is completely analogous to the halogenation of ketones and involves a slow tautomeric equilibrium followed by rapid oxidation, viz. 

The oxidation of N, A-dimethylaniline by aerated, ethanolic cupric chloride to give a mixture of products including methyl and crystal violets is simple second-order when an excess of amine is used Presumably Cu(I) is re-oxidised by dissolved oxygen, for otherwise the observed linearity of log [residual amine] versus time plots would not be found as Cu(II) disappears. Under nitrogen the kinetics are complex, but a new optical absorption (472 and 1007 nm) appears immediately on mixing the reactants. This absorption decays whilst a new one at 740 nm develops. The latter absorption originates from a 1 1 complex formulated... 

The standard free energy change for this reaction is generally positive at all temperatures because oxides are invariably stabler than chlorides. An exception to this rule occurs in the case of copper because cupric chloride is more stable than cupric oxide. At 500 °C, the standard free energy change (AG°) for the reaction... 

In the manufacture of printed circuit boards, the unwanted copper is etched away by acid solutions of cupric chloride (Equation 1.1). As the copper dissolves, the effectiveness of the solution tails and it must be regenerated. The traditional way of doing this is to oxidize the cuprous ion produced with acidified hydrogen peroxide. During the process the volume of solution increases steadily and the copper in the surplus liquor is precipitated as copper oxide and usually landfilled. 

The remaining cuprous chloride is oxidized and also reacts with environmental water (or water vapor) to form more cupric chloride, as well as basic cupric chloride ... 

An improved synthesis of dithieno[3,2-A2, 3 -<7]thiophene 15a has been achieved from 2,3-dibromothiophene 304 (Scheme 57). Lithiation of 2,3-dibromothiophene 304 using -butyllithium followed by oxidative coupling with cupric chloride provided 3,3 -dibromo-2,2 -bithiophene 305 in 79% yield. Treatment of 305 with 2 equiv of -butyllithium in ether at —78 °C under nitrogen for 40 min and then adding benzenesulfonic acid thioanhydride and leaving the reaction mixture to reach room temperature afforded dithieno[3,2-A2, 3 -<7]thiophene 15a in 70% yield <2002TL1553>. 

Disubstituted 1,2,3-triazoles are usually minor components in the product mixtures obtained from reactions of triazole with electrophiles (see Section 5.01.5). The few regioselective syntheses of such compounds include a reaction of aminoacetophenones 1235 with hydrazines. The reaction with methylhydrazine proceeds well without any catalysis, but that with phenylhydrazine requires cupric chloride as a catalyst. It is assumed that hydrazone 1236 that forms in the first step is in a tautomeric equilibrium with its azo form 1237. However, it is not clear how bond formation between the nitrogen atoms and oxidation to the triazole system occurs. 4-Aryltriazoles 1238 are obtained in 50-66% yield (Scheme 205) <2003SC3513>. 

Palladium-catalyzed oxidation of hydrocarbons has been a matter of intense research for about four decades. The field was initiated by the development of the aerobic oxidation of ethylene to acetaldehyde catalyzed by palladium chloride and co-catalyzed by cupric chloride (the Wacker process, equation l)1. 

The catalyst, and the source of the oxygen, is cupric oxide dissolved in a molten mixture of cupric chloride and potassium chloride. Developed by Lummus Corporation. 

With the synthesis of novel [l,2,4]triazolo[4,3-A]pyridazine derivatives 385 from the pyridazylhydrazone 384, Doring et al. followed a well-established route (cf. Table 12, entry 11) <2005T5942>. The specificity of this study is, however, the use of cupric chloride as an oxidizing agent (which has not been used before). 

Oxidative cyclization of hydrazones to fused [l,2,4]triazoles by means of cupric chloride was already discussed above for a related pyridazine derivative. The same method was also applied successfully for ring closure of 428 to 429 in good to excellent yields (Scheme 53) <2005T5942>. 

Arsine reacts with cupric chloride solution to give cupric arsenide. Oxidation with stannic chloride, SnCR, forms hydrogen diarsenide, AS4H2. It reacts with dilute silver nitrate solution forming metallic silver. 

Treatment of 1,3-dimethyl-1,2,3-triazolium tosylate (490) with sodium hydride in dimethylformamide gives the ylide (491). Oxidation of this ylide (491) using oxygen and cupric chloride catalyst gave the meso-ionic l,2,3-triazol-4-one 176, Ri = R = Me, R - H. ... 

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