5-bromo-2,3-dihydropyran-6-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 3-bromo-5,6-dihydropyran-2-one (Org. Syn., 1996, 73, 231) (74.9 g), phenylboronic acid (51.8 g), potassium carbonate (294 g) and tetrakis(triphenylphosphine) palladium(0) (3.4 g) in toluene was heated (100° C.) under an atmosphere of nitrogen for 24 hours. The cooled solution was diluted by addition of ethyl acetate (1000 ml) and water (1000 ml) and the mixture filtered through Hiflo™. The organic phase was dried (MgSO4), evaporated in vacuo and the residue crystallised from methanol and then toluene to give the title compound, 43 g. mp. 100-101° C. the mixture filtered through Hiflo™ The organic phase was dried (MgSO4) evaporated in vacuo the residue crystallised from methanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 3-bromo-5,6-dihydropyran-2-one (Org. Syn., 1996, 73, 231) (74.9 g), phenylboronic acid (51.8 g), potassium carbonate (294 g) and tetrakis(triphenylphosphine) palladium(0) (3.4 g) in toluene was heated (100° C.) under an atmosphere of nitrogen for 24 hours. The cooled solution was diluted by addition of ethyl acetate (1000 ml) and water (1000 ml) and the mixture filtered through Hiflo™. The organic phase was dried (MgSO4), evaporated in vacuo and the residue crystallised from methanol and then toluene to give the title compound, 43 g. mp. 100-101° C. the mixture filtered through Hiflo™ The organic phase was dried (MgSO4) evaporated in vacuo the residue crystallised from methanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 3-bromo-5,6-dihydropyran-2-one (87.4 g, 0.49mol), 3,4-difluorophenylboronic acid (91.4 g, 0.58 mol), potassium carbonate (99.9 g, 0.72 mol), potassium fluoride (85.4 g, 1.47 mol) and tetrakis(triphenylphosphine)palladium (0) (12 g, 0.01 mol) in tetrahydrofuran (600 ml) was thoroughly degassed and then heated at reflux for 48 hours under an atmosphere of nitrogen. The solution was cooled to room temperature and water (1000 ml) and ethyl acetate (1000 ml) were added. The organic phase was washed with saturated brine and dried (MgSO4) and the solvent removed in vacuo. The residue was dissolved in dichloromethane and the solution filtered through a pad of silica gel. The filtrate was evaporated to dryness and the residue recrystallized from diethyl ether to give the title compound 34.6 g. mp 82-85° C. 1H NMR (360 MHz. CDCl3) δ 2.63 (2H, td J 6.2 Hz and 4.5 Hz), 4.49 (2H, t J 6.3 Hz), 7.01 (1H, t J 4.5 Hz), 7.11-7.23 (2H, m), 7.32-7.38 (1H, m). heated at reflux for 48 hours under an atmosphere of nitrogen The organic phase was washed with saturated brine dried (MgSO4) the solvent removed in vacuo The residue was dissolved in dichloromethane the solution filtered through a pad of silica gel The filtrate was evaporated to dryness the residue recrystallized from diethyl ether

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 3-bromo-5,6-dihydropyran-2-one (Org. Syn., 1996, 73, 231) (74.9 g), phenylboronic acid (51.8 g), potassium carbonate (294 g) and tetrakis(triphenylphosphine) palladium(0) (3.4 g) in toluene was heated (100° C.) under an atmosphere of nitrogen for 24 hours. The cooled solution was diluted by addition of ethyl acetate (1000 ml) and water (1000 ml) and the mixture filtered through Hiflo™. The organic phase was dried (MgSO4), evaporated in vacuo and the residue crystallised from methanol and then toluene to give the title compound, 43 g. mp. 100-101° C. the mixture filtered through Hiflo™ The organic phase was dried (MgSO4) evaporated in vacuo the residue crystallised from methanol