2-(3-Butynyloxy)tetrahydro-2H-pyran → 4-Acetylamino-3-[4-(tetrahydro-pyran-2-yloxy)-but-1-ynyl]-benzoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a degassed solution of 4-acetylamino-3-iodo-benzoic acid methyl ester (41.4 g, 130 mmol) in DMF (200 mL) and triethylamine (40 mL) were added PdCl2(PPh3)2 (3.99 g, 5.68 mmol) and copper (I) iodide (7.43 g, 39.0 mmol). A degassed solution of 2-but-3-ynyloxy-tetrahydro-pyran (30.1 g, 195 mmol) in DMF (100 mL) and triethylamine (20 mL) was added at 80° C. over a period of 1 hour under nitrogen. After the addition, the reaction mixture was stirred at 80° C. for 2 hours and then cooled to room temperature. Solvent was evaporated under reduced pressure. Ethyl acetate (200 mL) was added. The solid was filtered, and washed with ethyl acetate. The ethyl acetate solution was washed with brine, and dried over anhydrous Na2SO4. The organic phase was concentrated to dryness, to afford 66.8 g crude 4-acetylamino-3-[4-(tetrahydro-pyran-2-yloxy)-but-1-ynyl]-benzoic acid methyl ester. This was used in next step without further purification.

Provenance & Evidence