Bargellini coumarin synthesis

What is Bargellini coumarin synthesis?

In 1925, Bargellini first documented the reaction now referred to as Bargellini coumarin synthesis or Bargellini condensation. This chemical reaction involves the use of acetic anhydride and sodium phenylacetates to produce coumarins from o-oxyarylketones.

Bargellini coumarin synthesis - Bargellini condensation
Bargellini coumarin synthesis

R = alkyl, aryl

Bargellini’s earlier research in 1911 explored the condensation of benzoylacetonitriles with polyhydric phenols, such as resorcinol, which resulted in the production of corresponding coumarins. This reaction is now commonly known as the Bargellini condensation, but it is often inconvenient and typically results in low yields. Consequently, alternative methods have been developed to synthesize coumarins.

One such alternative involves modifying the Bargellini condensation. For example, the reaction can be carried out via the condensation of o-methoxybenzaldehydes with arylacetonitrile followed by demethylation with pyridine hydrochloride. Alternatively, coumarins can be produced from 2,5-dimethoxycinnamic acid with boron tribromide.

References

  • Bargellini, G., Gazz. Chim. Ital., 1925, 55, 945
  • Bargellini, G. and Forti-Forli, G., Gazz, Chim. Ital., 1911, 41, 747
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