- Ring contractions of 4-oxoquinolizine-3-diazonium tetrafluoroborates, by an aza wolff rearrangement, to alkyl indolizine-3-carboxylates
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The 1-substituted 3-amino-4H-quinolizin-4-ones 13, available in two steps from 10 and methyl (Z)-2-benzyloxycarbonylamino-3-(dimethylamino)propenoate (11), were diazotized to give the stable diazonium tetrafluoroborates 7a and 7b. Heating of these diazonium salts in alcohols gave mixtures of 3-unsubstituted quinolizine derivatives 8a and 8b and the alkyl indolizine-3-carboxylates 9a-h. The ratio of the two types of products 8 and 9 was dependent on the type of alcohol employed. Thus, treatment of 7a or 7b with 2-propanol predominantly resulted in the 3-unsubstituted quinolizinones 8, while treatment of 7a or 7b with primary alcohols gave the indolizine-3-carboxylates 9 as the major products in most cases. The transformation of the 4-oxoquinolizine-3-diazonium tetrafluoroborates 7a and 7b into the alkyl indolizine-3-carboxylates 9a-h represents the first example of a Wolff rearrangement in the fused cyclic α-diazoamide series.
- Recnik, Simon,Svete, Jurij,Stanovnik, Branko
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p. 3705 - 3709
(2007/10/03)
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- Quinolizinone compounds and pharmaceutical composition comprising the same, useful as anti-ulcerative and anti-allergic agents
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The invention relates to novel quinolizinone compounds having inhibitory activity on allergies and ulcers, of the formula: STR1 wherein R1 is tetrazolylcarbamoyl; R7 is hydrogen or aryl selected from phenyl, tolyl, xylyl, cumenyl, naphthyl and biphenylyl; R2 is hydrogen, hydroxy, lower alkyl or lower alkoxy; R3 is hydrogen, hydroxy, lower alkyl, lower alkoxy, lower alkenyloxy, phenyl, napthyl, biphenylyl, phenyl having one or more substituent(s) selected from halogen, lower alkyl and lower alkoxy, arylthio selected from phenylthio, tolylthio, xylylthio, cumenylthio, naphthylthio and biphenylthio, aroyl selected from benzoyl, toluoyl and naphthoyl, ar(lower)alkyl selected from phenyl(lower)alkyl, tolyl(lower)alkyl, xylyl(lower)alkyl, cumenyl(lower)alkyl, naphthyl(lower)alkyl and biphenylyl(lower)alkyl, arenesulfonyl selected from benzenesulfonyl and p-toluenesulfonyl, arylamino selected from phenylamino, naphthylamino, biphenylylamino, phenylamino having lower alkyl on the nitrogen atom or aryloxy selected from phenoxy and tolyloxy; or pharmaceutically acceptable salts thereof.
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- A CONVENIENT SYNTHESIS OF 4-OXO-4H-QUINOLIZINES
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By reacting α-substituted picolines (1) (or their synthetic equivalents) with β,β-dichloropropenals (4) (or their synthetic equivalents) substituted 1-(2-pyridyl)-4,4-dichloro-1,3-butadienes (6) were produced.Compounds (6) were smoothly cyclized to the corresponding 4-oxo-4H-quinolizines (8) bearing substituents in the 1 and/or 3 positions.
- Forti, Luciana,Gelmi, Maria Luisa,Pocar, Donato,Varallo, Marinella
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p. 1401 - 1410
(2007/10/02)
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