β Scribed by C.M. Wright; D.R. Levering
No coin nor oath required. For personal study only.
A convenient electrolytic method for the preparation of simplegem-dinitroparaffins has been found. The first step in the reaction is the electrolytic oxidation of a silver anode to silver ions. In the preparation of 1,1-dinitroethane, the silver ions react in the anode compartment of the electrolysis cell with nitrite and ethylnitronate ions to form the potassium saIt of dinitroethane in solution and silver metal on the surface of the electrode. The product can be separated in highly pure form by crystallization from the anode solution. The reaction variables have been investigated and a unique electrolysis cell, containing a bed of powdered silver as the anode, has been designed. This cell permits continuous operation without loss of silver from the anode. A mechanism for the reaction, involving an intermediate complex containing ethylnitronate, nitrite and silver ions in a ratio of 1 : 1:2 has been postulated. Ll-Dinltropropane and 2,2-dinitropropane have been prepared by analogous reactions.
IN previous studies, the electrolytic preparation of aliphatic dinitrocompounds has been limited to the use of inert electrodes. The maximum yields reported areβ’less than 40 %and the product has always been contaminated with a mixture of other compounds. Several authors-r" have reported that nitro-paraffins yield small amounts of Β«-dinitroparaffins when anodically oxidized at a platinum or graphite electrode. Bahner' has more recently shown that gem-dinitroparaffins can be obtained in significant quantity by the electrolysis of secondary nitroparaffins in aqueous alkaline solution in the presence of excess nitrite.
Kaplan and Shechter," in a paper presented at this symposium, have shown that gem-dinitrocompounds can be prepared by the reaction: R", _ _
This reaction proceeds in good yields at room temperature in aqueous alkaline solution. The reaction has the serious drawback, from an economic point of view, that it requires the separation and handling of large amounts of silver 1
π SIMILAR VOLUMES
The method described by Makosza and Wawrzyniewicz 1,2,3 is a most useful addition to the arsenal of dihalocarbene-generating reactions4. The two-phase reaction system consisting of the olefins, chloroform, and 50% aqueous sodium hydroxide with a tetraalkylammonium chloride as catalyst provides a par
An account is given of new methods for the electrochemical preparation ofp-aminophenol by the reduction of nitrobenxene. It has been found that control of the electrode potential at a specific value using recently developed potentiostats brings about a marked improvement in the efficiency of the pre