- Amine-controlled reduction of 2-aminochromone-3-carbaldehyde with Zn and acetic acid
-
On heating with zinc in acetic acid 2-(N-arylamino)chromone-3-carbaldehydes produce 2-(N-arylamino)-3-methylchromones, whereas 2-(N-alkylamino)chromone-3-carbaldehydes produce 4-hydroxy-3-methylcoumarin in moderate yields. Reduction of an aldehyde functio
- Biswas, Pritam,Ghosh, Jaydip,Sarkar, Tapas,Bandyopadhyay, Chandrakanta
-
-
Read Online
- Synthesis of coumarins, 4-hydroxycoumarins, and 4-hydroxyquinolinones by tellurium-triggered cyclizations
-
Coumarins, 4-hydroxycoumarins, and 4-hydroxyquinolin-2(1H)-ones can be conveniently prepared by treatment of α-halocarboxylic acid esters of salicylaldehyde, o-hydroxyacetophenone, methyl salicylate, and methyl N-methyl- or N-phenylanthranilates with sodium or lithium telluride. Phenylketene formation competes with cyclization of the α-chlorophenylacetate ester of methyl salicylate as demonstrated by a trapping experiment with benzylamine. Elemental tellurium may be recovered and reused.
- Dittmer, Donald C.,Li, Qun,Avilov, Dimitry V.
-
p. 4682 - 4686
(2007/10/03)
-