Cyclization of 1-benzyl-1,2-dihydro-2-(substituted methylene)quinolines to pyrrolo[1,2-a]quinoline derivatives.
1-Alkyl-2-alkylthioquinolinium salts were prepared from 1-alkyl-2(1H)-quinolones via 1-alkyl-2(1H)-thioquinolones in two steps. Under mild conditions, the reaction of 1-alkyl-2-alkylthioquinolinium iodides with active methylene compounds in the presence of sodium hydride afforded 1-alkyl-1,2-dihydro-2-(substituted methylene)quinolines in good yields. The cyclization of 1-benzylquinolines using acetic anhydride produced the corresponding pyrrolo[1,2-a]quinoline derivatives.
Fujita
Reiko
R
Tohoku Pharmaceutical University, Komatsushima, Sendai, Japan. refujita@tohoku-pharm.ac.jp
Hoshino
Masato
M
Tomisawa
Hiroshi
H
D000089:Acetic Anhydrides; D002855:Chromatography, Thin Layer; D003500:Cyclization; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D011758:Pyrroles / Q000737:chemistry*; D011804:Quinolines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D000089:Acetic Anhydrides; D007202:Indicators and Reagents; D011758:Pyrroles; D011804:Quinolines; C031800:acetic anhydride