Orthoamide, XLVI. Beiträge zur Chemie von Bis(dialkylamino)malononitrilen

Abstract

Ortho Amides, XLVI. — Contributions to the Chemistry of Bis(dialkylamino)malononitrilesThe reaction of chloroformamidinium chlorides 2 with sodium cyanide in the two‐phase system ether/water affords bis(di‐alkylamino)malononitriles 3 with good yields. From 3a and morpholine or aniline the guanidines 5 and 6 can be obtained, respectively. Alcohol‐free sodium ethoxide transforms 3a into the urea acetal 10b, whereas in the reaction of 3a with alkoxides in alcohol ortho carbamic esters 11a, b are produced. The malonic esters and acetoacetic esters 12 react with 3a in the presence of two equivalents of sodium hydride to give the ketene aminals 13. The reactions of 3a with malononitrile furnishes the guanidinium salt 14, which is cyclized by hydrogen chloride to the pyridinetricarbonitrile 15. In the presence of sodium hydride, 3a and malononitrile or cyanoacetic esters 17 form the ketene aminal 16 and the 1,2,3‐tricyanopropenides 18a–c, respectively. The analogous salts 20 and 21 result from the reaction of 3a with the barbituric acid derivatives 19a, and b, respectively. Hydrogen chloride reacts in ether with 3a to afford the piperazinetetracarbonitrile 22. Reaction of carboxylic acid chloride yields the cyanoformamidinium salt 28a; byproducts are acyl cyanides 29 and dimeric acyl cyanides 30. Triethyloxonium tetrafluoroborate transforms 3a into the salt 28b. Bromine and iodine react with 3a to produce the salts 28c, d and 28e, f, respectively, depending on the stoichiometric ratios of the starting materials. The thiocyanate 28g is prepared from sulfur and 3a.