Microwave-mediated and customery synthesis of N-benzoyl- or N-substituted benzoyl-N,N'-dialkylureas from arylcarboxylic acids and N,N'-disubstituted carbodiimides under solvent-free conditions

Abstract

bons rendimentos em condições livre de solvente. Primeiramente, a reação entre um ácido carboxílico e uma carbodiimida dissubstituída foi feita empregando radiação de microondas, e depois a mesma reação foi realizada sob aquecimento convencional. Os rendimentos são comparáveis em ambos os casos.An easy, efficient and quick synthesis of N-benzoyl-(and N-substituted benzoyl)-N,N′-dialkylureas, in good yields, under solvent-free conditions is described. First, the reaction between a carboxylic acid and a disubstituted carbodiimide was carried out employing microwave radiation, and later on the same reaction was performed separately under dry heating without any radiation. The yields are comparable in both cases.

The multicomponent approach to N-methyl peptides: total synthesis of antibacterial (–)-viridic acid and analogues

“…Intermediate 7 was converted into amine 8 under acidic conditions, and coupled directly to N , N -dimethylanthranilic acid ( 9 ). It was already reported that carbodiimide-mediated couplings involving aromatic carboxylic acids such as 9 can result in the formation of N -acylurea adducts through competitive N–O rearrangement [18–19]. In order to overcome this problem the mixed-carbonate method was used [20].…”

1,3-Dicyclohexyl-3-[(pyridin-2-yl)carbonyl]urea monohydrate from synchrotron radiation

“…For the preparation of N-(arenecarbonyl)-N,N 0 -dicyclohexylurea derivatives, see: Kaiser et al (2008);Neves Filho et al (2007); Schotman (1991). For the crystal structures of related N-(arenecarbonyl)-N,N 0 -dicyclohexylurea derivatives, see: Ché rioux et al (2002); Cai et al (2009); Dhinaa et al (2010); Orea Flores et al (2006); Gallagher et al (1999); Wang & Zhou (2008); Wu et al (2006).…”

“…Reactions of arenecarboxylic acids with dicyclohexylcarbodiimide (DCC) in the presence of a catalyst, such as 1-hydroxybenzotriazole, HOBt, produce N-(arenecarbonyl)-N,N′-dicyclohexylureas (Kaiser et al, 2008;Neves Filho et al, 2007;Schotman, 1991). Several crystal structures of N-(arenecarbonyl)-N,N′-dicyclohexylurea derivatives have been reported (Chérioux et al, 2002;Cai et al, 2009;Dhinaa et al, 2010;Orea Flores et al, 2006;Gallagher et al, 1999;Wang et al, 2008;Wu et al, 2006).…”

N-Heterocyclic Carbene Catalyzed Oxidative Coupling of Aldehydes with Carbodiimides under Aerobic Conditions: Efficient Synthesis of N-Acylureas

“…In 1995, reactions of substituted benzoic acids with N,N ′-dicyclohexylcarbodiimide (DCC) in the presence of [Bu 3 NH][ClO 4 ]/[Bu 3 N] buffer were shown to afford N -acylurea derivatives, and several improved reactions of DCC with carboxylic acids have been reported . Recently, Srivastava reported the reaction of benzoic acid derivatives and N,N ′-disubstituted carbodiimides under solvent-free conditions in a microwave oven in 2007 . As far as we know, there are no examples of the catalytic synthesis of N -acylureas from aldehydes and N,N ′-disubstituted carbodiimides.…”

“…14 Recently, Srivastava reported the reaction of benzoic acid derivatives and N,N 0 -disubstituted carbodiimides under solvent-free conditions in a microwave oven in 2007. 15 As far as we know, there are no examples of the catalytic synthesis of N-acylureas from aldehydes and N,N 0 -disubstituted carbodiimides. Herein, we present the first report on a highly effective coupling reaction of aldehydes with N,N 0 -disubstituted carbodiimides catalyzed by NHC under aerobic conditions using several N-heterocyclic carbene precursors (Figure 1).…”