6638-23-9Relevant articles and documents
Iminium Salts in Solid-State Syntheses Giving 100% Yield
Kaupp, Gerd,Schmeyers, Jens,Boy, Juergen
, p. 269 - 280 (2007/10/03)
Numerous reaction types in the field of iminium salts are performed in the gas-solid and solid-solid techniques in order to reach 100% yield. The stoichiometric runs are waste-free and do not require costly workup. Frequently, iminium salts were avoided, as acid catalysis was dispensable. Thioureas and α-halogenated ketones give a variety of 2-aminothiazoles via thiuronium salts in quantitative yield. A new intramolecular solid-state thermal condensation is reported. Enaminoketones are synthesized quantitatively from anilines and 1,3-diketones without catalysis and those can be used for quantitative solid-state 4-cascade reactions. Solid paraformaldehyde is used to produce methylene imines and internally trapped methylene iminium salts. Benzoylhydrazones are produced again without catalysis in the solid state. Vacuum and ball-mill techniques are particularly useful in the production of highly sensitive iminium salts. Hexahydro-1,3,5-triazines cyclorevert upon exposure to HCl gas to give solid arylmethylene iminium chlorides as new versatile reagents. These are used in arylaminomethylations of β-naphthol and of themselves to give Troeger's bases in 3-cascades. More direct are 4-cascade Troeger's base syntheses by dissolving hexahydro-1,3,5-triaryltriazines in trifluoroacetic acid. Alkylations of imines with trimethyloxonium tetrafluoroborate and triphenylmethyl cation give highly sensitive quaternary iminium salts in the ball-mill. The products are characterized by spectroscopic techniques and density functional theory (DFT) calculations at the B3LYP 6-31G* level. Molecular movements in the crystal and surface passivation are investigated with atomic force microscopy (AFM) techniques.
The Condensation of Cyclic Anhydrides with Schiff Bases. A Convenient Synthesis of 1,4,6-Triaryl-5-carboxy-2-oxo-1,2-dihydropyridines and 2,3-Diaryl-4-carboxy-1-oxo-1,2-dihydroisoquinolines
Mayadeo, M. S.,Kulkarni, S. J.,Deodhar, K. D.
, p. 87 - 88 (2007/10/02)
Condensation of Schiff bases of o-hydroxyarenecarboxaldehydes with 3-arylpentenedioic or homophthalic acid anhydrides was found to give 1,4,6-triaryl-5-carboxy-2-oxo-1,2-dihydropyridines and 2,3-diaryl-4-carboxy-1-oxo-1,2-dihydroisoquinolines, respectivel