Dehydrations, copper chloride

Experiment 36. — Supplies Test tubes, thermometer, 5 gm. each of fused calcium chloride, potassium nitrate, ammonium nitrate, dehydrated copper sulphate, i gm. each of sodium hydroxide and potassium hydroxide, and a few cubic centimeters of concentrated sulphuric acid. 

Measure 10 cc. of water into a test tube, take the temperature, add at one time 5 gm. of fused calcium chloride. As it dissolves, stir with the thermometer and observe the highest reading. Record in the proper place in the table below. Repeat successively with separate portions of water and the ammonium nitrate, potassium nitrate, -dehydrated copper sulphate, potassium hydroxide, sodium hydroxide, and concentrated sulphuric acid (add the acid to the water). Tabulate the results as follows —... 

Rahmes, M. H., Petroleum Refiner, 29, No. 8, 119 (1950). (New plant operating MEA, dehydration, caustic, and copper chloride units.)... 

Copper Chloride Cupric Chloride Dehydrate Eriochalcite (Anhydrous) ... 

Copper chloride dihydrate is an example of simple dehydration, which upon simple heating below the melting point is capable of losing its water of hydration ... 

Sour Gas—New Plant Operating ME., Dehydration, Caustic and Copper Chloride Units, Pet. Refiner, August, 1950, p. 118. 

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. 

The reaction is cataly2ed by all but the weakest acids. In the dehydration of ethanol over heterogeneous catalysts, such as alumina (342—346), ether is the main product below 260°C at higher temperatures both ether and ethylene are produced. Other catalysts used include siUca—alumina (347,348), copper sulfate, tin chloride, manganous chloride, aluminum chloride, chrome alum, and chromium sulfate (349,350). 

Butyl Ether. -Butyl ether is prepared by dehydration of -butyl alcohol by sulfuric acid or by catalytic dehydration over ferric chloride, copper sulfate, siUca, or alumina at high temperatures. It is an important solvent for Grignard reagents and other reactions that require an anhydrous, inert medium. -Butyl ether is also an excellent extracting agent for use with aqueous systems owing to its very low water-solubiUty. 

For example, the reaction of nitronates (123) with a zinc copper pair in ethanol followed by treatment of the intermediate with aqueous ammonium chloride a to give an equilibrium mixture of ketoximes (124) and their cyclic esters 125. Heating of this mixture b affords pyocoles (126). Successive treatment of nitronates (123) with boron trifluoride etherate and water c affords 1,4-diketones (127). Catalytic hydrogenation of acyl nitronates (123) over platinum dioxide d or 5% rhodium on aluminum oxide e gives a-hydroxypyrrolidines (128) or pyrrolidines 129, respectively. Finally, smooth dehydration of a-hydroxypyrrolidines (128) into pyrrolines (130f) can be performed. 

The conversion of 2-(o-chlorophenyl)-ethanol to dihydrobenzofurane was also promoted by copper(I) chloride in toluene in the presence of sodium hydride (3.44.), The choice of solvent was crucial to suppress undesired side reactions, such as dehydration or the loss of a formaldehyde fragment.54... 

The copper azide chloride, Cu(N3)a-3CuCla 6H,0 or Cu(Nj)a 3CuCla prepd by Straumanis Cirulis (Ref 16) expl at 207-8°. The hydrate cannot be dehydrated. Therefor the anhyd compd should be prepd from abs ale The general types of copper azide addn compds a)[Cu(N,) ] b)[Cu(N3)J c)... 

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