Synthesis of cyclic bis- and trismelamine derivatives and their complexation properties with barbiturates

Abstract

Cyclic bis- and trismelamine derivatives were prepared from cyanuric chloride by stepwise substitutions with appropriate amines. The complexation abilities of these melamine derivatives with barbituric acid derivatives were evaluated by UV-vis spectroscopy and (1)H NMR. The structure was also confirmed by X-ray crystallography. Both the acyclic and the cyclic bismelamine derivatives formed a 1 : 1 complex via six hydrogen bonds with barbituric acid derivatives. van't Hoff analyses on the complexation of the bismelamines with the barbituric acid derivative revealed that the complexation of the cyclic bismelamine was entropically favored and enthalpically less favored process than those of the acyclic bismelamine. X-Ray crystallographic analysis and (1)H NMR studies revealed that the cyclic trismelamine bound one barbituric acid derivative into the cavity via six hydrogen bonds by two melamine moieties and another barbituric acid via three hydrogen bonds by the residual melamine moiety.

Lipid Membrane Adhesion and Fusion Driven by Designed, Minimally Multivalent Hydrogen-Bonding Lipids

“…While there are many solutions to this problem in Nature, there are few non-native designed systems known. − We have previously reported our aqueous-phase studies on cyanurate (CA) and melamine (M) phospholipid derivatives that drive membrane chemistry via hydrogen-bonding interactions between the CA and M headgroups . There have been numerous studies on the CA-M system; though the parent compounds readily cocrystallize in a hydrogen-bonding network in water − and derivatives are well-known to assemble in low dielectric solvents − or when hydrophobically buried, derivative assembly generally does not occur in hydrogen-bonding solvents. ,− Indeed, without the phospholipid module, monoderivatived cyanurate (CA) and melamine (M) neither assemble nor inhibit interactions between the lipids in water (Figure ) . Surface multivalency of an assembled membrane provides binding avidity that greatly enhances the hydrogen-bonding interaction at the lipid−water interface. ,− The requisite density of CA/M modules for recognition was indicated by diminished interaction at CA-PE/M-PE concentrations of less than 70% in fluid phase (ePC) membranes.…”

“…[1][2][3][4][5][6][7][8] We have previously reported our aqueous-phase studies on cyanurate (CA) and melamine (M) phospholipid derivatives that drive membrane chemistry via hydrogen-bonding interactions between the CA and M headgroups. 9 There have been numerous studies on the CA-M system; though the parent compounds readily cocrystallize in a hydrogen-bonding network in water [10][11][12] and derivatives are well-known to assemble in low dielectric solvents [13][14][15][16] or when hydrophobically buried, 17 derivative assembly generally does not occur in hydrogen-bonding solvents. 12,[18][19][20] Indeed, without the phospholipid module, monoderivatived cyanurate (CA) and melamine (M) neither assemble nor inhibit interactions between the lipids in water (Figure 1).…”

Insight into the multicomponent reaction mechanisms of prop-2-en-1-amine and ethyl propiolate with alloxan derivative: A density functional theory study

“…Barbiturate derivatives have been widely used as anaesthetic, hypnotic and other therapeutic drugs [2][3][4][5][6][7][8][9][10][11]. Due to the wide applications of barbiturates in organic and medicinal chemistry, much effort has already been made in synthesizing various types of barbiturates experimentally [12][13][14][15][16][17][18][19][20][21]. For example, Volonterio et al reported a general and straightforward one-pot sequential synthesis of 1,3,5-trisubstituted barbiturates in very mild conditions [12].…”