One-Step Formation of N-Alkenyl-malonamides and N-Alkenyl-thiomalonamides from Carbamoyl Meldrum's Acids

Abstract

A one-pot synthesis for the preparation of N-alkenyl-malonamides and N-alkenyl-thiomalonamides was developed. 5-[Hydroxy/mercapto(aryl/alkylamino)methylene]-2,2-dimethyl-1,3-dioxane-4,6-dione act as a source of ketenes that react with the tautomeric form of alkyl-(2-phenyl-propylidene)-amines. A possible [2 + 2] or [4 + 2] cycloaddition product of ketene to imines was not observed.

GRAPHICAL ABSTRACT

Keywords:

• Acylations
• amides
• ketenes
• Meldrum's acid
• tautomerism

ACKNOWLEDGMENT

Scientific work was financed from Funds for Science in 2010–2011 as research project NN204 088338.

Notes

^a 1 eq of 2a was used.

^b 4 eq of 2a was used.

^c 1 eq of 2a was used and the reaction mixture was saturated with HCl.

^d 1.5 eq of TMS-Cl was added.