Copper sulfate pentahydrate oxidant

Potassium permanganate adsorbed on copper sulfate pentahydrate oxidizes dithiol 112 into 1,2-dithiepane 113 (Equation 35) <1998S1587>. 

The use of sofid supports in conjunction with permanganate reactions leads to modification of the reactivity and selectivity of the oxidant. The use of an inert support, such as bentonite (see Clays), copper sulfate pentahydrate, molecular sieves (qv) (151), or sifica, results in an oxidant that does not react with alkenes, but can be used, for example, to convert alcohols to ketones (152). A sofid supported permanganate reagent, composed of copper sulfate pentahydrate and potassium permanganate (153), has been shown to readily convert secondary alcohols into ketones under mild conditions, and in contrast to traditional permanganate reactivity, the reagent does not react with double bonds (154). 

Zinc. Next to sodium, zinc is the most used reductant. It is available in powder, dust, and granular (mossy) forms. Zinc gets coated by a l er of zinc oxide which must be removed to activate it before it can reduce effectively. It can easily be activated by shaking 3 to 4 min. in a 1% to 2% hydrochloric acid solution. This means for every 98 ml of water volume, add 2 ml of coned hydrochloric acid. Then wash this solution with water, ethatiol, acetone, and ether. Ot activation can be accomplished by washing zinc in a solution of anhydrous zinc chloride (a very small amount) in ether, alcohol, or tetrahydrofuran. Another way is to stir 180 g of zinc in a solution of 1 g copper sulfate pentahydrate. Personally, I like the HCl acid method. 

Zinc dust is frequently covered with a thin layer of zinc oxide which deactivates its surface and causes induction periods in reactions with compounds. This disadvantage can be removed by a proper activation of zinc dust immediately prior to use. Such an activation can be achieved by a 3-4-minute contact with very dilute (0.5-2%) hydrochloric acid followed by washing with water, ethanol, acetone and ether [/55]. Similar activation is carried out in situ by a small amount of anhydrous zinc chloride [156 or zinc bromide [157 in alcohol, ether or tetrahydrofuran. Another way of activating zinc dust is by its conversion to a zinc-copper couple by stirring it (180g) with a solution of 1 g of copper sulfate pentahydrate in 35 ml of water [/55]. 

The role of the supports in the reactions just described is not clear. Even less clear is the function of copper sulfate pentahydrate, in the presence of which oxidations with solid potassium permanganate result in excellent yields of ketones. Traces of water are essential. Primary alcohols, on the other hand, give poor yields of aldehydes and acids [844 (equation 255). 

COPPER SULFATE PENTAHYDRATE (7758-98-7) Violent reaction with strong bases, hydroxylamine, magnesium. Contact with potassium chlorate is potentially explosive. Incompatible with acetylene. Aqueous solution is an acid incompatible with sulfuric acid, caustics, ammonia, aliphatic amines, alkanolamines, amides, alkylene oxides, epichlorohydrin, organic anhydrides, isocyanates, vinyl acetate. 

Copper(II) sulfate monohydrate [10257-54-2] CuS04-H2 0, which is almost white in color, is hygroscopic and packaging must contain moisture barriers. This product is produced by dehydration of the pentahydrate at 120—150°C. Trituration of stoichiometric quantities of copper(II) oxide and sulfuric acid can be used to prepare a material of limited purity. The advantages of the monohydrate as opposed to the pentahydrate are lowered freight cost and quickness of solubilization. However, these advantages are offset by the dustiness of the product and probably less than one percent of copper sulfate is used in the monohydrate form. 

The synthesis of 7-methoxyindole was accomplished starting from 1-acetylindoline (34). Regioselec-tive intr uction of iodine was achieved using thallium trifluoroacetate, then potassium iodide. Deacetylation and oxidation to the indole (35), followed by reaction with sodium methoxide in DMF, gave the 7-methoxyindole (36) in 48% overall yield (Scheme 13). More recently, Somei et al have reported that treating the intermediate thallium species with copper(II) sulfate pentahydrate gives directly the l-acetyl-2,3-dihydro-7-hydroxyindole (37) in 42% yield (Scheme 14). It remains to be seen whether this is a general process. 

Ketones are also produced from amines by oxidation with KMn04 supported on copper(II) sulfate pentahydrate in dichloromethane. Bridged alkenes such as norbornene are cleaved with the same reagent. This method is an alternative to ozonolysis. ... 

The use of a reducing agent, most commonly sodium ascorbate, introduced by Fokin and coworkers [6], is a convenient and practical alternative to oxygen-free conditions. Its combination with a copper(II) salt, such as the readily available and stable copper(II) sulfate pentahydrate or copper(ll) acetate, has become the method of choice for preparative synthesis of 1,2,3-triazoles. Water appears to be an ideal solvent, capable of supporting copper(l) acetylides in their reactive state, especially when they are formed in situ. The aqueous ascorbate procedure often furnishes triazole products in nearly quantitative yield and greater than 90% purity, without the need for ligands or protection of the reaction mixture from oxygen (Scheme 10.2C). Of course, copper(I) salts can also be used in combination with ascorbate, wherein it converts any oxidized copper(ll) species back to the catalytically active -Hi oxidation state. 

Busan 1030 Copper naphthenate Copper 8-qulnollnolate Cupric sulfate pentahydrate DIacetone alcohol, DIdecyIdImonlum chloride Glyceryl losinate Lead naphthenate Magnesium sllbofluorlde Methyl rosinate. Mineral spirits Noramium DA.50 Paraffin-, Pentaerythrltyl hydrogenated rosinate. Sodium chromate Sodium fluoride Tdbutyltln oxide, VM P naphtha Zbc naphthenate... 

Calcium D-pantothenate Cholecalciferol Choline chloride Copper carbonate (ic) Cupric sulfate pentahydrate Ferrous fumarate Magnesium gluconate Magnesium sulfate anhydrous Manganese carbonate Manganese oxide (ous) Manganese sulfate (ous) Menadione DL-Methionine L-Methionine MSG Niacinamide D-Panthenol Potassium iodide Retinol Tocopherol D-a-Tocopherol DL-a-Tocopherol d-o-Tocopheryl acetate animal feed ingredient Casein Com (Zea mays) meal Lactose Sodium sulfate Whey animal feed supplement Ammonium acetate Ammonium perchlorate Calcium phosphate monobasic anhydrous Calcium pyrophosphate Cobalt phosphate (ous)... 

Copper oxide (ic) Cupric sulfate anhydrous Cupric sulfate pentahydrate Lithium bromide Nickel... 

The solvent-free potassium permanganate promoted oxidation of alcohols into the corresponding carbonyl derivatives has been examined by Luu et al. (2008). Secondary alcohols were oxidized very efficiently to the corresponding ketones at ambient temperature by KMnO absorbed on a fourfold molar amount of copper (II) sulfate pentahydrate. The reaction rate was enhanced considerably by ultrasonic irradiation also, but drastically in the presence of microwave irradiation, may be due... 

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