Tetramethylammonium 1,1,2,3,3-penTACYANOPROPENIDE

Tetramethylammonium 1,1,2,3,3 -pentacyanopropenide has been prepared by the base-catalyzed hydrolysis of tctracyano-ethylene,3 and by the present method, which is more economical of tetracyanoethylene. 

Tetramethylammonium 1,1,2,3,3-pentacyanopropenide is useful for preparation of pentacyanopropenide salts of other metal and quaternary ammonium cations by metathesis.8 The free acid, which may be obtained by use of an ion-exchange resin,3 has an ionization constant comparable to that of a strong mineral acid (pK < —8.5 the anion is not detectably protonated in 12M sulfuric acid).4... 

A hitherto unpublished preparation of diazomethane is given on p. 16. The starting material is the commercially available bis-(N-methyl-N-nitroso)-terephthalamide, and the procedure conveniently affords 0.76 to 0.86 mole of ethereal diazomethane. Ozonization in polar solvents is illustrated by two preparations (pp. 41 and 46). Many other unusual and interesting preparations are included, such as ruthenocene (p. 96), N,N-di thyltri-chlorovinylamine (p. 21), phenyl tert-butyl ether (p. 91), and tetramethylammonium 1,1,2,3,3-pentacyanopropenide (p. 99). 

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