Orthoamide, LXIX [1]. Beiträge zur Synthese N,N,N´,N´,N´´-peralkylierter Guanidine und N,N,N´,N´,N´´䞲,N´´-persubstituierter Guanidiniumsalze / Orthoamides, LXIX [1]. Contributions to the Synthesis of N, N, N´, N´, N´-peralkylated Guanidines and N, N, N´, N´, N´´, N´´-persubstituted Guanidinium Salts

Abstract

N, N, N´, N´-Tetraalkyl-chloroformamidinium chlorides 6 are prepared from N, N, N´, N´-tetraalkylureas 5 and phosgene in acetonitrile. The iminium salts 6 react with primary and secondary amines in the presence of triethylamine to give N, N, N´, N´, N´´-pentasubstituted and N, N, N´, N´, N´´, N´´- hexasubstituted guanidinium salts 7 and 8, respectively, Treatment of the guanidinium salts 7 with sodium hydroxide in excess affords the N, N, N´N´, N´´-pentasubstituted guanidines 9a - 9aa. Additionally, the N, N, N´, N´, N´´-pentasubstituted and N, N, N´, N´, N´´, N´´-hexasubstituted guanidinium salts 7l´, 7p´ and 8a - c can be obtained from the reaction mixtures by addition of stoichiometric amounts of sodium hydroxide. A modified method is described for the preparation of guanidinium salts possessing dialkylamino substituents consisting of two long-chain alkyl groups (>C14). Some guanidines 9 were alkylated with allyl chloride and bromide, ethyl bromide, butyl bromide, benzyl bromide and chloride, dimethyl sulfate, diethyl sulfate, and methyl methansulfonate to give the corresponding guanidinium salts 11 - 15. By alkylation of the N, N, N´, N´, N´´-pentasubstituted guanidine 9v with triethyloxonium tetrafluoroborate the guandinium tetrafluoroborate 16a is accessible. N-Functionalized guanidinium salts 17 - 18a - c result from the reaction of N, N, N´, N´, N´´-pentasubstituted guanidines with ethyl bromoacetate and bromoacetonitrile, respectively, and subsequent anion exchange with sodium tetraphenylborate. N, N, N´, N´-Tetramethylguanidine (21) adds to ethyl acrylate to give the labile guanidine 22, which forms the guanidinium salt 23a on treatment with methyl iodide. Zwitterionic guanidinium salts 25 result, when N, N, N´, N´, N´´-pentasubstituted guanidines are treated with sultones 24.

N,N,N′,N′-Tetramethyl-N′′,N′′-dipropylguanidinium chloride–(2Z)-2,3-diaminobut-2-enedinitrile (1/1)

“…For the crystal structure of (2Z)-2,3-diaminobut-2-enedinitrile, see: Penfold & Lipscomb (1961). For the synthesis of hexaalkyl-substituted guanidinium chlorides, see: Kantlehner et al (1984) and for the synthesis and crystal structures of hexaalkyl-substituted guanidinium salts, see: Kantlehner et al (2010). For studies on the water-absorption ability of guanidinium salts, see: Kunkel (2008).…”

“…Comment (2Z)-2,3-Diaminobut-2-enedinitrile (Z-DAMN), is considered to be the tetramer of hydrogen cyanide and its crystal structure has been determined more than fifty years ago (Penfold & Lipscomb, 1961). On the other hand the synthesis of hexaalkyl substituted guanidinium chlorides is well described in literature (Kantlehner et al, 1984), but only scanty crystal structure data are available (Kantlehner et al, 2010). For preparation of guanidinium chlorides, in first step N,N,N′,N′-tetraalkylureas are activated with phosgene to give chloroformamidinium chlorides, which in a next step react with secondary amines in the presence of triethylamine (Kantlehner et al, 1984).…”

Computational study of substituent effects on the gas‐phase stabilities of N‐phenylguanidinium ions

“…In the past two decades, ionic liquids (ILs) have attracted much attention and were proposed for a broad range of applications in various areas of natural and engineering sciences . Guanidinium ions constitute a new class of ionic liquids used for various applications . Some authors including one of us have systematically synthesized many hexaalkylguanidinium ionic liquids to investigate their fundamental physicochemical properties as well as to investigate the application to electrochemistry including the development of lithium‐ion batteries .…”

Guanidinium‐Based Phosphotungstates and Ionic Liquids as Catalysts and Solvents for the Epoxidation of Olefins with Hydrogen Peroxide

“…Similar to imidazolium salts, several guanidinium salts exhibit typical ionic liquid characteristics and can be favourably employed as reaction media [18,26] as well as catalysts. [27,28] Recently, remarkable progress was made with respect to the optimization of synthetic strategies, [29][30][31][32][33] computational [34,35] and structural characterization [29,36] as well as a better understanding of their properties. [31,33,[37][38][39][40] Based on these new insights, the applications of guanidinium salts can be vastly extended.…”