Magnesium acetate, 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). 

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. 

A classic example of a solid—fluid ceramic powder synthesis reaction is that of calcination and dehydration of natural or synthetic raw materials. Calcination reactions are common for the production of many oxides from carbonates, hydrates, sulfates, nitrates, acetates, oxalates, citrates, and so forth. In general, the reactions produce an oxide and a volatile gaseous reaction product, such as CO2, SOg, or HgO. The most extensively studied reactions of this type are the decompositions of magnesium hydroxide, magnesium carbonate, and calcium carbonate. Depending on the particular conditions of time, temperature, ambient pressure of CO2, relative humidity, particle size, and so on, the process may be controlled by a surface reaction, gas diffusion to the reacting... 

This results in 63 per cent, yield when the same quantities of materials are used as in the preceding preparation, the 2-bromo-6-methylphenyl-arsinic acid being replaced by 2-bromo-4-methylphenylarsinic acid. The compound crystallises in colourless needles, melting with decomposition at 158° to 159° C., readily soluble in acetic acid, methyl and ethyl alcohols, and acetone, very sparingly soluble in water. The sodium, potassium and ammonium salts are readily soluble in water the silver, mercuric and lead salts form white, flocculent precipitates, insoluble in cold or hot water the silver salt is soluble in ammonia the mercurous, calcium and barium salts arc white precipitates, insoluble in cold but soluble in hot water. The magnesium salt is obtained when a solution of the ammonium salt is boiled with magnesia mixture. 

Inconsistencies in the literature on the decompositions of Group IIA metal acetates have been attributed [37] to the sensitivity of thermogravimetric measurements to sample configuration, and the influence of product accumulation. The decompositions of magnesium and cadmium acetates involve formation of amorphous intermediates and partial melting. 

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