Magnesium sulfate, decomposition

To a suspension of 3.0 g of 7-[D-(-)-a-amino-p-hydroxyphenylacetamido] -3-[5-(1-methyl-1,2,3,4-tetrazolyl)thiomethyl] -A3arboxylic acid in 29 ml of water was added 0.95 g of anhydrous potassium carbonate. After the solution was formed, 15 ml of ethyl acetate was added to the solution, and 1.35 g of 4-ethyl-2,3-dioxo-1 -piperazinocarbonyl chloride was added to the resulting solution at 0°C to 5°C over a period of 15 minutes, and then the mixture was reacted at 0°C to 5°C for 30 minutes. After the reaction, an aqueous layer was separated off, 40 ml of ethyl acetate and 10 ml of acetone were added to the aqueous layer, and then the resulting solution was adjusted to a pH of 2.0 by addition of dilute hydrochloric acid. Thereafter, an organic layer was separated off, the organic layer was washed two times with 10 ml of water, dried over anhydrous magnesium sulfate, and the solvent was removed by distillation under reduced pressure. The residue was dissolved in 10 mi of acetone, and 60 ml of 2-propanol was added to the solution to deposit crystals. The deposited crystals were collected by filtration, washed with 2-propanol, and then dried to obtain 3.27 g of 7-[D-(-)-a-(4-ethyl-2,3-dioxo)-1 -piperazinocarbonylamino)-p-hydroxyphenylacetamido] -3-[5-(1 -methyl-1,2,3,4-tetrazolyl)thiomethyl]-A product forms crystals, MP 1BB°C to 190°C (with decomposition). 

Recently, the influence of the preparation method of various MgO samples on their catalytic activity in the MPV reaction of cyclohexanone with 2-propanol has been reported 202). The oxides were prepared by various synthetic procedures including calcination of commercially available magnesium hydroxide and magnesium carbonate calcination of magnesium hydroxides obtained from magnesium nitrate and magnesium sulfate sol-gel synthesis and precipitation by decomposition of urea. It was concluded that the efficiency of the catalytic hydrogen transfer process was directly related to the number of basic sites in the solid. Thus, the MgO (MgO-2 sample in Table IV) prepared by hydration and subsequent calcination of a MgO sample that had been obtained from commercially available Mg(OH)2 was the most basic and the most active for the MPV process, and the MgO samples with similar populations of basic sites exhibited similar activities (Table IV). 

In the laboratory, magnesium hydroxide may be prepared by double decomposition reactions by adding a soluble hydroxide to solutions of magnesium salts i.e., adding caustic soda solution to magnesium sulfate solution ... 

Magnesium sulfate undergoes three important types of reactions in aqueous solutions double decomposition, double salt formation, and formation of oxysulfate cements. Many insoluble magnesium salts may be precipitated out by double decomposition reactions ... 

To a vigorously stirred suspension of 40 gm (0.138 mole) of mercuric oxide in 100 ml of water is added slowly 15 gm (0.134 mole) of A-ethyl-A -isobutyl-hydrazine. After the addition has been completed, stirring is continued for an additional hr at room temperature. The mercury and mercury oxides are then removed by filtration. The precipitate is washed with ether and the aqueous phase is extracted with ether. The ether solutions are combined and dried with anhydrous magnesium sulfate. Then the ether is distilled off. The residue is distilled at 105°-107°C (741 mm Hg) yield 5.8 gm (40%). On redistillation, an appreciable quantity of a high-boiling residue is left behind, possibly because of thermal decomposition. 

Many other cases arise that cannot be considered here. For example, two or more double salts may form, depending upon the ratio of the salts in solution. The two salts may have no common ion, as potassium chloride and magnesium sulfate. On evaporation, either of these two or the two salts formed by their double decomposition may separate as well as any one of a number of double salts. Sometimes a double salt cannot be obtained unless the temperature is below a given point, called the transition point while in other cases the temperature must be above the transition point. Thus, the salt known as kainite, MgS04-KCh3H20, cannot be obtained above 83° while with astrakanite, MgS04 Na2S0v4H20, the temperature must be above 4.5 and below 60°. 

Prolonged drying of the cyclobutenone over potassium carbonate resulted in product decomposition. Anhydrous magnesium sulfate was found to hydrolyze the product during the thermolysis step. 

Chloro-2-[3-(bromomethyl)-5-methyl-4H-l,2,4-triazol-4-yl]-benzophenone A solution of 5-chloro-2-[3-(hydroxymethyl)-5-methyl-4H-l,2,4-triazol-4-yl]-benzophenone (328 mg, 0.001 mol) in dry, hydrocarbon-stabilized chloroform (5 ml) was cooled in an ice-bath and treated with phosphorus tribromide (0.1 ml). The colorless solution was kept in the ice-bath for 55 minutes, at ambient temperature (22-24°C), for 5 hours. The resulting yellow solution was poured into a mixture of ice and dilute sodium bicarbonate. This mixture was extracted with chloroform. The extract was washed with brine, dried over anhydrous magnesium sulfate and concentrated. The residue was crystallized from methylene chloride-ethyl acetate to give 0.285 g of melting point 200-240°C (decomposition) and 0.030 g of melting point 200-220°C (decomposition) of 5-chloro-2-[3-(bromomethyl)-5-methyl-4H-l,2,4-triazol-4-yl]benzophenone. The analytical sample had a melting point of 200-240°C. 

Decomposition of Hcxadecyl Phenyl Tellurium Dichloride in DMF7 A stirred suspension of0.2g (0.40 mmol) hexadecyl phenyl tellurium dichloride, 30 mg (0.51 mmol) of sodium chloride, and 2 ml of DMF is heated under nitrogen at 100° for 1 h. The mixture is Ihen allowed to cool to20 J, is poured into water, and extracted with hexane. The extract is dried with anhydrous magnesium sulfate and filtered through a short column of silica gel. The solvent is evaporated to leave l-chlorohexadecune as a colorless oil yield 96 mg (92%). 

Preparation,a [1, 135, at end]. Since a glass surface catalyzes the decomposition of the peracid, the reaction of m-chlorobenzoyl chloride with hydrogen peroxide in the presence of magnesium sulfate heptahydrate, aqueous sodium hydroxide, and dioxane is carried out in a polyethylene beaker (Nalgene). The product obtained contains 80-85% active oxygen. 

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