Homogeneous solution, rapid

Mechanical stirring is not necessary in work with homogeneous solutions except when it is desired to add a substance portion-wise or dropwise so as to bring it as rapidly as possible into intimate contact with the main bulk of the solution. This applies particularly in those cases where a precipitate is formed and adsorption may occur, or where heat is generated... 

A solution of the ketone (10 mg) in dry dioxane (5 ml) is placed in the cathode compartment of the cell. Then 10% deuteriosulfuric acid in deuterium oxide (5 ml) is added slowly with stirring. A small additional quantity of dioxane may be necessary to maintain a homogeneous solution. The anode compartment is filled with an identical solvent mixture and the electrode inserted. The current is adjusted to 1(X) milliamps and the electrolysis is continued for 6-10 hr with rapid stirring. The progress of the reaction is... 

B. 5-Hexynal. To a solution of 5.60 g. (0.050 mole) of 2,3-epoxycyclohexanone in 120 ml. of benzene in a 500-ml. round-bottomed flask is added 10.82 g. (0.051 mole) of trans-1 -amino-2,3 diphenylaziri-dine.2 Initially, after brief swirling at room temperature, the reaction mixture is a colorless, homogeneous solution however it rapidly turns yellow and cloudy due to separation of water. After 2 hours the benzene and water are removed as an azeotrope under reduced pressure on a rotary evaporator with the bath maintained at approximately 30°. The resulting crude mixture of diastereomeric hydrazones weighs 15.4 g. (Note 7) and is subjected directly to the fragmentation reaction (Note 8). 

Conversion of tight ion pairs into crown ether-separated ion pairs leads in many cases to increased basicity. For example, Dietrich and Lehn (1973) have shown that a homogeneous solution of sodium t-amyloxide in benzene is unable to deprotonate triphenylmethane, whereas the reaction occurs rapidly in the presence of [2.2.2]-cryptand [37]. In THF or diethyl ether, alkali metal enolates do not react with triphenyl- or diphenylmethane (Pierre et al.,... 

Oxidative nitration, a process discovered by Kaplan and Shechter, is probably the most efficient and useful method available for the synthesis of em-dinitroaliphatic compounds from the corresponding nitroalkanes. The process, which is an electron-transfer substitution at saturated carbon, involves treatment of the nitronate salts of primary or secondary nitroalkanes with silver nitrate and an inorganic nitrite in neutral or alkali media. The reaction is believed ° °° to proceed through the addition complex (82) which collapses and leads to oxidative addition of nitrite anion to the nitronate and reduction of silver from Ag+ to Ag . Reactions proceed rapidly in homogeneous solution between 0 and 30 °C. 

It has been found in checking that the use of 800 cc. of acid, while not necessary, gives a much less viscous solution, which becomes homogeneous more rapidly. 

The solution must not be evaporated to a volume that permits crystallization to begin before the ether is added. The addition of ether should be sufficiently rapid that the heavy syrup is diluted to a clear, homogeneous solution before crystallization begins. 

In homogeneous solution, the aminium cation radical may generate an olefin cation radical which reacts in cyclic fashion with another olefin before reaccepting an electron. This pathway relies on rapid bond-forming reactions compared with electron exchange. 

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