Efficient Palladium-Catalyzed Synthesis of the Styrene Intermediate of a Novel­ Herbicide, Indanofan

Abstract

2-[2-(3-Chlorophenyl)allyl]-2-ethylindan-1,3-dione is a key intermediate of indanofan, a novel herbicide. 2-[2-(3-Chlorophenyl)allyl]-2-ethylindan-1,3-dione was efficiently prepared by palladium-catalyzed coupling of 2-(3-chlorophenyl)prop-2-en-1-ol with 2-ethylindan-1,3-dione or palladium-catalyzed three-component coupling of allene, 3-bromochlorobenzene and 2-ethylindan-1,3-dione.

Key words

allenes - condensation - coupling - Heck reaction - palladium

References

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Sulfonated phosphine, PPh₃-(SO₃H)_n (n = 1-3), was prepared as described below: To a mixture of 60% H₂SO₄ (26 mL) and HNO₃ (53 mL) cooled in an ice-bath, was added Ph₃P (80 g), and the mixture was stirred at 60 °C for 3 h. The mixture was poured into ice, and neutralized with aq sat. NaOH and diluted with H₂O (1 L). The precipitate was filtered off, and recrystallized from EtOH to give sulfonated phosphine (8 g).

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Chem. Abstr. 1995, 123, 339398.