Abstract
1,5-Benzothiazepines derivatives were obtained first by starting
from 1,3-diphenylpropenone derivatives (chalcones) and 2-aminothiophenol
by using aluminosilicate solid catalysts. However,
diffusional limitations and the strong adsorption of products
on the catalyst are deleterious for catalyst activity and life.
Then a structured amorphous mesoporous catalyst with large
pores and mild acidity that works at higher temperatures allowed
us to obtain high conversions (99%) and selectivities
(98%) of the desired product. A one-pot synthesis of 1,5-benzothiazepines
that starts from benzaldehyde, acetophenone,
and 2-aminothiophenol with 95% yield was performed by
combining optimized solid base and acid catalysts in batch
mode as well as in a continuous-flow reactor system. Much
better conversion and selectivity as well as process intensification
has been achieved with the structured mesoporous materials
by avoiding intermediate and final neutralization and purification
steps required in the synthesis reported previously
that uses homogeneous catalysts.
