Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → Methyl 8-fluoroisoquinoline-3-carboxylate

Participants

Reaction Steps

2-Acetylamino-3-(2-[1,3]dioxan-2-yl-3-fluoro-phenyl)-acrylic acid methyl ester (10.6 g, 32.8 mmol) and pyridinium para-toluene sulfonate (2.06 g, 8.2 mmol) are heated to reflux for 20 hours in an acetone/water (120 ml/15 ml) mixture. The solvents are removed by evaporation and the aqueous residue is extracted with ethylacetate. The organic layer is washed with brine and dried over MgSO4 and evaporated. The crude product is recrystallised from ethylacetate/ether to afford 5.1 g of the desired compound. MS (ES+): m/e=206.2 (MH+)

Provenance & Evidence