Patent · US Expired

Process for regioselective demethylation of p-methoxy group in phenolic ester and diaryl ketone moieties

US7053218B2 · kind B2 · utility

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7Claims
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Inventors

Key dates

Filing dateSep 8, 2004
Grant dateMay 30, 2006
Priority date
Expiry dateSep 29, 2024

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C67/31
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

Demethylation of 3′, 4′-dimethoxy or 3′, 4′, 5′-trimethoxy benzoic ester of a phenol is carried out in the presence of an excess of aluminum halide in an organic solvent to get 4′-Hydroxy, 3′-methoxy or 4′ hydroxy, 3′, 5′-dimethoxy benzoic acid ester of a phenol. The reaction is also applicable to 3′, 4′, 5′-trimethoxy diaryl ketone and some natural products like reserpine.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.