211450-07-6Relevant academic research and scientific papers
An efficient procedure for the preparation of 4-substituted 5-aminoimidazoles
McLaughlin, Mark,Mohareb, Rafat M.,Rapoport, Henry
, p. 50 - 54 (2007/10/03)
The preparation of O-methylimidates from α-aminonitriles and their subsequent co-cyclization with primary amines to afford 4-substituted 5-aminoimidazoles was studied. It was found that the mildly acidic pyridinium p-toluenesulfonate efficiently catalyzed each stage of the reaction sequence: (a) the formation of the O-methylimidates, (b) their co-cyclization with a variety of primary amines, and (c) certain derivatizations of the resultant heterocycles. The developed reaction conditions tolerate a wide variety of α-aminonitriles and primary amine co-reactants. Thus, it is possible to easily prepare a diverse array of substituted heterocyclic compounds in good yield. The requisite α-aminonitriles were synthesized either from amino acids or by phase-transfer alkylation of a glycine anion equivalent. The unstable free 5-aminoimidazoles were normally protected in situ to provide derivatives (methyl imidates or N,N-dimethylamidines) that were amenable to characterization.
Regioselective synthesis of α,α-dialkylcyclopentanones from 1-hydroxycyclobutanecarboxylic acid or from O-protected cyclobutanone cyanohydrin
Estieu, Karine,Ollivier, Jean,Salauen, Jacques
, p. 8075 - 8090 (2007/10/03)
1-(1-Hydroxyalkyl)cyclobutanols 4a-f, readily available either from 1-hydroxycyclobutane carboxylic acid or from O-protected cyclobutanone cyanohydrin, appeared the most suitable precursors for a regioselective synthesis of cyclopentanones α,α- disubstituted with various similar or different alkyl, alkenyl, aryl or cycloalkyl groups. The key steps consist of acid or Grignard reagent induced C4→C5 ring expansions.
