Phosphorus oxide (P4O10) → 8-fluoro-3,4-dihydro-2H-benzo[4,5]thieno[3,2-c]pyridin-1-one

Participants

Reaction Steps

Using analogous conditions and workup as described for the preparation of Intermediate I-1d above, ethyl 2-(5-fluorobenzo[b]thiophen-2-yl)ethylcarbamate (I-50 f: 700 mg, 2.622 mmol) was reacted with P2O5 (749.78 mg, 5.28 mmol) and POCl3 (10 mL) to afford the crude product. Purification by column chromatography on silica gel (50% ethyl acetate in hexane) afforded 280 mg of the product (48.27% yield).

Provenance & Evidence