Synthesen mit Amidchloriden, III. Synthese und Reaktionen von Chlorformamidiniumchloriden

Abstract

Aus substituierten Harnstoffen oder Thioharnstoffen und Phosgen werden Chlorformamidiniumchloride synthetisiert. Die Hydrolyse tetrasubstituierter Chlorformamidiniumchloride liefert die entsprechenden Harnstoffe, während N.N′‐disubstituierte Derivate unter Abspaltung von Chlorwasserstoff in Carbodiimide übergehen. Tetramethyl‐chlorformamidiniumchlorid reagiert mit alkoholfreiem Natriumäthylat zu Tetramethylharnstoff‐diäthylacetal. In Gegenwart von Alkohol hingegen setzen sich die tetrasubstituierten Chloride mit Alkoholaten zu N.N‐ disubstituierten Orthocarbamidsäureestern um. Mit Natriumhydrogensulfid lassen sich die Formamidiniumsalze in Thioharnstoffe überführen. Primäre Stickstoffbasen kondensieren mit tetrasubstituierten Chlorformamidiniumchloriden zu pentasubstituierten Guanidinen.

Crystal Structure of Hexamethylguanidinium Hexafluorosilicate Hexahydrate

“…Reactions (1) and (2) were modifications of those previously reported by Eilingsfeld and coworkers [9] and Igumnov and coworkers [7], respectively. Steps (3) and (4) are analogous to those, previously reported for the preparations of hexamethylpiperidinium fluoride [5] and…”

A Convenient Synthesis and Some Characteristic Reactions of Novel Propiolamidinium Salts

“…However, their synthesis of propiolamidinium chloride 3a-Cl (see Scheme 2 below) from benzoyl chloride and 3,3,3-tris(dimethylamino)-1-phenylprop-1-yne remains the only example of this method so far reported. 5 We explored another approach to salts 3 without success: the reaction of alkynyl lithium or alkynyl Grignard compounds with chlorotetramethylformamidinium chloride 6 did not afford the desired propiolamidinium salts. In this context, it must be remembered that the reaction of phenyl lithium and higher alkyl lithium compounds with this chloroformamidinium salt also did not take the expected addition/substitution pathway, but instead gave products derived from radical intermediates.…”

Synthesis and investigation of new cyclic haloamidinium salts

“…CCDC 1445899 (19) and 1445900 (20) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/ data_request/cif.…”

“…There are only a few examples with bromine [18] or iodine [19]. 2-Chloroimidazolium salts can be easily generated from urea and thiourea compounds when they are treated with phosgene [20], oxalyl chloride [21], phosphoryl chloride [22], or phosphorous pentachloride [23] (Scheme 4). 1,3-Disubstituted-2-chloro-imidazolium salts are used as dehydrating reagents due to their strong hygroscopic properties [24].…”