ChemInform Abstract: Synthesis of Quaternary Salts, Anhydro Bases and 9-(1,2-Dimethoxycarbonyl-3-benzoyl-7-indolizinylmethylene) -4-azafluorene on the Basis of 9-(γ-Pyridylmethylene)azafluorenes.
✍ Scribed by N. M. KOLYADINA; A. T. SOLDATENKOV; O. M. BAKTIBAEV; N. S. PROSTAKOV
- Publisher
- John Wiley and Sons
- Year
- 2010
- Weight
- 36 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0931-7597
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✦ Synopsis
Synthesis of Quaternary Salts, Anhydro Bases and 9-(1,2-Dimethoxycarbonyl-3-benzoyl-7-indolizinylmethylene) -4-azafluorene on the Basis of 9-(γ-Pyridylmethylene)azafluorenes.
-Methylation of pyridylmethyleneazafluorene (I) with one equivalent of methyl iodide proceeds exclusively at the pyridine nitrogen to afford compound (III). Attempts to separate the E/Z-mixture by a second methylation step are not successful since also the sterically hindered Z-isomer undergoes methylation of the azafluorene nitrogen although in lower amounts. Dialkylation of the pyridylmethyleneazafluorene (V) with phenacyl bromide affords the dibromide (VII) which in alkaline solution undergoes dehydrogenation to furnish the diylide (X). The dibromide (VII) is shown to undergo 1,3-dipolar cycloaddition to acetylenedicarboxylate (VIII) to produce the indolizine derivative (IX). -(KOLYADINA, N. M.;