Electron-donating, electron-withdrawing containing substituted benzaldehydes
and sterically hindered those such as 2-nitrobenzaldehyde, 2-chlorobenzaldehyde, and 2,4-dichlorobanzaldehyde are well reacted in this 3-CR to afford the desired products.
In this paper, we wish to present a simple one-pot protocol for synthesis of pyrano[3,2-c]quinolines and furano quinolines using nano-SCA, benzaldehyde
, aniline, and 3,4-dihydro-2H-pyran in THF as solvent and room temperature conditions.
But in a fermenting cell, the out-of-the-ordinary benzaldehyde
is attracted to the next step of the energy pathway: NADP +.
In a model reaction benzaldehyde
arylaldehyde and methyl acrylate thylacrylate were added in DMSO solvent (Scheme 1).
In a typical reaction few drops of acetic acid were added in stirred mixture of benzophenone- Schiff base (3.0 mmol) and substituted benzaldehydes
or different ketones (3.0 mmol) in methanol.
Pyrazolo [5, 4-d] benzopyrans had been synthesize in one step with good yield by the reaction of 2-pyrazolin-5-ones with orthohydroxy benzaldehydes
in presence of hydrochloric acid.
Hypothesis: The reaction conducted on electron rich benzaldehydes
should result in even larger shifts towards the products of the secondary and tertiary Leuckart reactions.
Physical data of iodo hydroxy benzaldehydes
Entry Substrate Product M.P.
Hypothesis: The reaction conducted on benzaldehydes
with electron-withdrawing substituents may produce lower yields of the by-products (substituted N,N-dibenzyl-N-methylamines) and higher yields of the main products, substituted N-benzyl-N-methylformamides.
During the study on hydroxylation of indoles with numerous benzaldehydes
we found that an increase in the concentration of this catalyst from 10 to 20 mol% does not increase the yields and not effected the reaction time.
They can be obtained from the respective substituted benzaldehydes
via the intermediate substituted benzylformamides.
[p.9] 3:20 APPLICATION OF THE ACCELERATED LEUCKART REACTION TO SUBSTITUTED BENZALDEHYDES
. Mikhail M.