Phosphorus oxide (P4O10) → 6-Methyl-3,4-dihydroisoquinolin-1(2H)-one

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Reaction Steps

Ethyl 3-methylphenethylcarbamate (I-69c: 13.5 g, 65.217 mmol) was reacted with P2O5 (18.51 g, 130.434 mmol) and POCl3 (135 mL) at 110° C. for 1 hour. The reaction mass was concentrated under reduced pressure, quenched with ice, basified using saturated NaHCO3 solution and extracted using ethyl acetate. The organic layer was washed with brine solution, dried over Na2SO4 and concentrated under reduced pressure to afford the crude product. Purification by column chromatography on silica gel (1% methanol in DCM) afforded 2 g of the product (19% yield). LCMS: 75.24%, m/z=162.3 (M+1)

Provenance & Evidence