- A new synthesis of the linearly fused [1,2,4]triazolo[1,5-b]isoquinoline ring. Observation of an unexpected Dimroth rearrangement
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A new and general synthesis of the linearly fused [1,2,4]triazolo[1,5-b]isoquinoline ring system starting from 2,3-diaminoisoquinolinium salts has been elaborated. Starting compounds bearing an alkyl group in position 4 easily reacted with aldehydes to yield the cyclized products. In the case of a lack of electron donating group in position 4 (e.g., unsubstituted or 4-cyano substituted diamino derivatives) a Dimroth rearrangement took place under the same reaction conditions to yield 3-isoquinolylhydrazones. The mechanism of this unexpected transformation has been verified by isotope labelling experiments. Clarification of the reaction mechanism allowed finding proper reaction conditions to eliminate the rearrangement route, and thus, to perfect successful ring closure to the fused triazoles.
- Filák, László,Riedl, Zsuzsanna,Egyed, Orsolya,Czugler, Mátyás,Hoang, Cuong N.,Schantl, Joachim G.,Hajós, Gy?rgy
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p. 1101 - 1113
(2008/09/17)
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- Linearly Fused Isoquinolines. 3. Positional Effect of Substitution on Equilibrium of Tetrazole-Azide Systems. Anomalous Behavior in Trifluoroacetic Acid
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A new method for synthesis of heteroaromatic azides has been elaborated, and a series of substituted tetrazoloisoquinoline derivatives has been synthesized.The effect of R1 and R4 substituents on the equilibrium between 3-azid
- Messmer, Andras,Hajos, Gyoergy
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p. 843 - 846
(2007/10/02)
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