Zinc mercuric chloride

Zinc/mercuric chloride Ethylene derivatives from ketones... 

Method 2 (Martin, 1942). A mixture of 200 g. of zinc wool, 15 g. of mercuric chloride, 10 ml. of concentrated h3 drochloric acid and 250 ml. of water is stirred or shaken for 5 minutes. The aqueous solution is decanted, and the amalgamated zinc is covered with 150 ml. of water and 200 ml. of concentrated hydrochloric acid. The material to be reduced, usually about 0-3-0-4 mole, is then added immediately, and the reaction is commenced. 

The amine (Imol) is added to a solution of anhydrous zinc chloride (Imol) in concentrated hydrochloric acid (42mL) in ethanol (200mL, or less depending on the solubility of the double salt). The solution is stirred for Ih and the precipitated salt is filtered off and recrystallised from ethanol. The free base is recovered by adding excess of 5-ION NaOH (to dissolve the zinc hydroxide that separates) and is steam distilled. Mercuric chloride in hot water can be used instead of zinc chloride and the salt is crystallised from 1% hydrochloric acid. Other double salts have been used, e.g. cuprous salts, but are not as convenient as the above salts. 

The exchange of aromatic protons can be effected in the absence of any -OH or —NH2 activating group during the course of a Clemmensen reduction in deuteriochloric and deuterioacetic acid mixture (see section Ill-D). This reaction has been carried out with various tricyclic diterpenes and is best illustrated by the conversion of dehydroabietic acid into its 12,14-d2-labeled analog (40 -+ 41).Amalgamated zinc is reportedly necessary for the exchange reaction since the results are less satisfactory when a zinc chloride-mercuric chloride mixture is used. 

The reduction of 2-methyl-1,2,3,4-tetrahydro-y-carboline (92) with zinc and hydrochloric acid in the presence of mercuric chloride gives the indolenine derivative, 2-methyl-l,2,3,4,4a,9b-hexahydro-y-carbo-line (93). A related compound, 4,9b-diethyl-2-methyl-l,2,3,4,4a,9b-hexahydro-y-carboline (96), was obtained by catalytic hydrogenation of 95, which was prepared by Fischer ring closure of the phenyl-hydrazone 94. The stereochemistry of the B/C ring junction in these... 

B. Amalgamated, Zinc [Mercury alloy (Hg, Zn)]. Zinc powder (206 g., 3.15 moles) is placed in a 1-1. beaker, covered with 250 ml. of aqueous 10% hydrochloric acid, and stirred for 2 minutes. The acid is then decanted and replaced by distilled water, the mixture is stirred, and the supernatant is decanted. Washing is continued in this way until the water is neutral to litmus. A warm solution of 40 g. (0.15 mole) of mercuric chloride [Mercury chloride (HgCl2)] in 250 ml. of distilled water is then poured onto the zinc, and the mixture is stirred gently for 10 minutes. After filtration, the powder is washed with 250 ml. of distilled water, five 250-ml. portions of 95% ethanol, and five 250-ml. portions of anhydrous ether. Drying under vacuum gives 196 g. of zinc amalgam. 

The amalgamated zinc may be prepared by adding 1500 g. of clean granulated zinc to 600 ml. of 5% mercuric chloride solution. After standing for 2 hours with occasional shaking, the liquid is decanted and the zinc is used immediately. 

Alternatively,21500 g. of granulated zinc is added to a solution of 62.5 g. of mercuric chloride and 62.5 ml. of concentrated hydrochloric acid in 1875 ml. of water. The mixture is shaken for about 5 minutes, the liquid decanted, and the zinc used immediately. 

Boliden/Norzink A method for removing mercury vapor from zinc smelter off-gases by scrubbing with a solution of mercuric chloride ... 

An aluminium-mercury couple acts in the same way as zinc dust. This aluminium amalgam, prepared by the action of mercuric chloride on aluminium (preferably granulated), is also suitable for reducing substances dissolved in ether or alcohol the water which is required is slowly added drop by drop. (The method is that of H. Wislicenus.) The extent of the reduction varies according to the nitro-compound concerned, but corresponds approximately to the effect of zinc dust in a neutral medium. Consequently reduction usually does not proceed beyond the hydroxylamine stage. 

Preparation of the Zinc Amalgam. —Granulated zinc in thin pieces or, still better, zinc foil 0-15 to 0-25 mm. thick and cut into small strips, is left for one hour with frequent shaking in contact with an equal weight of 5 per cent aqueous mercuric chloride solution. The solution is then poured off and the metal washed once with fresh water. 

The zinc is amalgamated in the reaction flask by covering it with a solution of 4 g. of mercuric chloride in 300 cc. of water. Occasional agitation during one-half hour is sufficient for amal-... 

Gutzeit test analy chem A test for arsenic zinc and dilute sulfuric acid are added to the substance, which is then covered with a filter paper moistened with mercuric chloride solution a yellow spot forms on the paper if arsenic is in the sample. gut,sTt, test ... 

Mossy zinc is activated by converting to zinc amalgam by brief immersion in amalgam solution. (Use 40 g mossy zinc immersed in 4 g mercuric chloride, 4 ml concentrated HCl acid, and 40 ml of water.) This type of amalgam can be used with powdered zinc also. 

Another Zinc Reduction. Prepare or activate the zinc as follows 400 g of mossy zinc is treated with 800 ml of 5% aqueous solution of mercuric chloride for 1 hour. Decant the solution off and use the zinc right away. Add. 834 mole of compound to be reduced to the zinc amalgam, followed by as much HCl acid (.834 mole) diluted in as much water as is required to cover all the zinc. Reflux for 6 hours while adding small portions of dilute HCL acid. Cool, separate the upper, wash free of acid (a few portions of dilute sodium hydroxide), dry and distill to get about a 79% yield of product. 

In a one-liter flask fitted with a reflux condenser, 400 g (5,3 mol, 3.2 equivalent) of mossy zinc is treated with 800 ml of a 5% aqueous solution of mercuric chloride for 1 hour. The solution is decanted then 100 g (0.835 mol) of acetophenone is added followed by as much hydrochloric acid diluted with the same volume of water as is needed to cover all the zinc. The mixture is refluxed for 6 hours during which time additional dilute hydrochloric acid is added in small portions. After cooling the upper layer is separated, washed free of acid, dried and distilled to give 70g (79%) of ethylbenzene, b.p. 135-136°. 

Zinc dust (10 g) is shaken vigorously with a solution of 0.8 g of mercuric chloride and 0.5 ml of concentrated hydrochloric acid in 10ml of water for 5 minutes. The supernatant liquid is decanted, 20 ml of water and 2 ml of concentrated hydrochloric acid is added to the residue, and 5 g of chromic chloride is added portionwise with swirling in a current of carbon dioxide. The dark blue solution is kept under carbon dioxide until used. 

Zinc enolate 4, prepared from acetylene ether pyridine i-oxide, mercuric chloride, and zinc, adds to aldehydes to form a-chloro-3-hydroxy esters 5 in good yields ( ). Subsequent treatment with base gives trans-epoxyesters, one of which 6 is converted to 2-amino-2-deoxy-D-ribose stereoselectively in good yields (O. 

We read in the experimental section A mixture of 300 g of 1-benzoyl-5-keto-l,2,2a,3,4,5-hexahydrobenz[cd]indole (2), 300 g of activated zinc, 1.0 g of mercuric chloride, 6 L of dry benzene and 90 g of methyl bromoacetate (la) was prepared in a 12 L, 3-neck flaskfittedwith a stirrer, reflux condenser and heating mantle. The mixture was heated under reflux and stirred, and after an induction period of 10-30 minutes the reaction started, and the solution became cloudy. After 3.5 hours 90 g of methyl bromoacetate and 20 g of zinc were added, and after five hours, 75 g of the bromoester and 60 g of zinc were added. Refluxing and stirring were maintained for a total of six hours, after which the reaction mix was allowed to cool and stand overnight . 

Vanadium predpitates the metal from solutions of salts of gold, silver, platinum, and iridium, and reduces solutions of mercuric chloride, cupric chloride and ferric chloride to mercurous chloride, cuprous chloride, and ferrous chloride, respectively. In these reactions the vanadium passes into solution as the tetravalent ion. No precipitation or reduction ensues, however, when vanadium is added to solutions of divalent salts of zinc, cadmium, nickel, and lead. From these reactions it has been estimated that the electrolytic potential of the change, vanadium (metal)—>-tetravalent ions, is about —0 3 to —0 4 volt, which is approximately equal to the electrolytic solution pressure of copper. This figure is a little uncertain through the difficulty of securing pure vanadium.5... 

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