Synthesis of optically active polyheterocycles containing pyrrolidine, imidazole, and 1,2,3-triazole rings
摘要:
Optically active polyheterocycles containing pyrrolidine, imidazole, and 1,2,3-triazole units were obtained via a multistep synthesis with the [3+2] cycloaddition of Boc-protected (S)-(pyrrolidin-2-yl) methyl azide with 2-ethynylimidazoles in the presence of CuI (CuAAC reaction) as the key step. Typical for terminal alkynes, the reactions occurred regioselectively and 1,4-disubstituted 1,2,3-triazoles were formed exclusively. The deprotection of the pyrrolidine N-atom was performed by treatment with TFA under standard conditions. (c) 2015 Elsevier Ltd. All rights reserved.
Exploration of 4,5-dimethyl-1H-imidazole N-oxide derivatives in the synthesis of new achiral and chiral ionic liquids
摘要:
New 1-alkoxy-3-alkyl-4,5-dimethylimidazolium bromides were synthesized by alkylation of the corresponding 1-alkylimidazole 3-oxides, which were conveniently prepared via condensation of alpha-(hydroxyimino)ketones, primary aliphatic amines, and formaldehyde. By using enantiomerically pure chiral amines, optically active imidazolium Salts were obtained. Treatment with sodium tetrafluoroborate in acetone yielded the corresponding imidazolium tetrafluoroborates. All these compounds, with only one exception, were obtained as oils, which are considered as potential ionic liquids and 'chiral ionic liquids'. The reduction of the chiral or non-chiral 1-alkylimidazole 3-oxides with Raney-Ni, followed by alkylation with alkyl bromides and subsequent ion exchange to tetra fluoroborates, gave the corresponding 1,3-dialkylimidazolium salts, most of them showing properties of ionic liquids. The alkylation of 1-butyl-4,5-dimethylimidazole 3-oxide and the corresponding imidazole, respectively, with 1,3-dibromopropane led to the first bis-imidazolium dibromides and bis-tetrafluoroborates. (c) 2009 Elsevier Ltd. All rights reserved.
ABSTRACT We have developed improved general simple methods for large-scale preparation of polyalkylated imidazoles by improved multicomponent synthesis from commercially available starting materials. A large range of NH- and N-alkyl-polyalkylimidazoles (40 in total, including novel compounds) has been synthesized. GRAPHICAL ABSTRACT
Disclosed are a series of hydroxyl purine compounds and the use thereof as PDE2 or TNFα inhibitors, in particular, the compounds as shown in formula (I), or tautomers thereof or pharmaceutically acceptable salts thereof.
Disclosed are a series of hydroxyl purine compounds and the use thereof as PDE2 or TNFα inhibitors, in particular, the compounds as shown in formula (I), or tautomers thereof or pharmaceutically acceptable salts thereof.