123914-19-2Relevant academic research and scientific papers
Synthesis and biological evaluation of novel imidazole-containing macrocycles
Nshimyumukiza, Prosper,Van Den Berge, Emilie,Delest, Bruno,Mijatovic, Tatjana,Kiss, Robert,Marchand-Brynaert, Jacqueline,Robiette, Rapha?l
, p. 4515 - 4520 (2010)
A new family of compounds made of a 5-aryl-1H-imidazole motif included in a macrocycle has been designed and synthesized. The synthesis of the imidazole core makes use of our previously developed method for the regioselective preparation of 1,2,5-trisubstituted imidazoles while the construction of the macrocycle is based on a three steps sequence: SNAr, Suzuki coupling, and RCM reaction. Biological evaluation of synthesized imidazole-containing macrocycles revealed that they display actual binding activity toward A3 adenosine (h) receptor, dopamine D1 (h) receptor, chloride channel (GABA-gated), and choline transporter (h) CHT1.
Extending pummerer reaction chemistry. Synthesis studies in the phakellin alkaloid area
Feldman, Ken S.,Skoumbourdis, Amanda P.,Fodor, Matthew D.
, p. 8076 - 8086 (2007)
(Chemical Equation Presented) The syntheses of (±)- dibromophakellstatin and, from this species, (±)-dibromophakellin are described. Oxidative cyclization of a phenylthiolated dihydrooroidin derivative triggered by a Pummerer reaction constitutes the key
Divergent and regioselective synthesis of 1,2,4- and 1,2,5-trisubstituted imidazoles
Delest, Bruno,Nshimyumukiza, Prosper,Fasbender, Olivier,Tinant, Bernard,Marchand-Brynaert, Jacqueline,Darro, Francis,Robiette, Raphael
, p. 6816 - 6823 (2008/12/22)
(Chemical Equation Presented) A divergent and regioselective synthesis of 1,2,4- and 1,2,5-trisubstituted imidazoles from a readily available (two steps) common intermediate has been developed. This methodology is based on the regiocontrolled N-alkylation of 1-(N,N-dimethylsulfamoyl)-5-iodo-2-phenylthio- 1H-imidazole (10). When this intermediate is engaged in reaction with methyl triflate, selective formation of the corresponding 1,2,5-trisubsituted 1H-imidazole is observed. NMR studies have revealed that this regioselectivity can be accounted for by in situ rapid isomerization of 10 into its 1,2,4-isomer (13) followed by regiospecific N-alkylation of the latter. Conversely, when key intermediate 10 is slowly added to Meerwein's salt, isomerization can be constrained and regiospecific N-alkylation of 10 leads to 1,2,4-trisubstituted 1H-imidazole with a high selectivity. The general character of this methodology has been illustrated by showing that iodine in position 4 or 5 could be easily substituted by an aryl group by Suzuki coupling, whereas the phenylthio group at position 2 could, after oxidation into sulfone, be displaced by nucleophilic substitution.
Extending pummerer reaction chemistry. Synthesis of (±)- dibromophakellstatin by oxidative cyclization of an imidazole derivative
Feldman, Ken S.,Skoumbourdis, Amanda P.
, p. 929 - 931 (2007/10/03)
(Chemical Equation Presented) The diastereoselective oxidative cyclization of a dihydrooroidin derivative is reported. The thioimidate product formed by application of a new variant of the Pummerer reaction serves as a precursor to dibromophakellstatin.
A General Route to 4-Substituted Imidazoles
Katritzky, Alan R.,Slawinski, Jaroslaw J.,Brunner, Frederic,Gorun, Sergiu
, p. 1139 - 1145 (2007/10/02)
Literature routes to di(imidazol-4-yl)methanol (1a) dinitrate and tri(imidazol-4-yl)methanol (2a) trihydrochloride were improved to give 32 and 16percent overall yields, respectively; but we failed to synthesize bis- (1b) and tris-(1-methylimidazol-4-yl)methanol (2b) by the methylation of the corresponding N-methoxymethyl compounds (3; x=2 and x=3).Attempted 4-lithiation of the 1,2,5-protected imidazole (4a) with BuLi-TMEDA failed, giving after hydrolysis 1-methyl-5-trimethylsilylimidazole (4b); similar failures were observed for 2,5-dicarboxy-1-methylimidazole, which after metallation with BuLi-TMEDA and hydrolysis afforded 1-methylimidazole-5-carboxylic acid (5).Our attempts to obtain 4-bromo-1-methylimidazole (10a) and 4-bromo-1-ethylimidazole suitable for a halogen-lithium exchange or for Grignard reaction also failed.Attempted selective lithiation of 2-phenylthio-1-tritylimidazole (16) at the 4-position, then theatment with ethyl formate, led only to a mixture of 4- and 5-substituted products in very low yield, and 1-diethoxymethyl-2-phenylthioimidazole (18) was unstable and difficult to purify. 4-Bromoimidazole with two mol equiv. of t-butyl-lithium gives 1,4-dilithioimidazole, which is now shown to provide a general route to 4-substituted imidazoles.
