Yield:-

Reaction Conditions:

with iodine;magnesium in tetrahydrofuran;hexane;toluene;

Steps:

P.2 Synthesis of ethyl 2-(1,3-dioxan-2-yl)phenylglyoxylate

Production Example 2 Synthesis of ethyl 2-(1,3-dioxan-2-yl)phenylglyoxylate A 36.5 g (150 mmol) portion of 2-(1,3-dioxan-2-yl)bromobenzene was added dropwise to a mixture of 3.72 g (153 mmol) of magnesium, 0.03 g of iodine and 30 ml of tetrahydrofuran, while heating under reflux. After additional 2 hours of heating under reflux, this was cooled to room temperature, and the resulting brown solution was added dropwise to 90 ml of toluene solution containing 43.8 g (300 mmol) of diethyl oxalate, while keeping the inner temperature to -3 to 0°C. After completion of the dropwise addition, this was returned to room temperature, poured into 300 ml of saturated ammonium chloride aqueous solution and extracted with 200 ml of ethyl acetate. The organic layer was washed twice with 100 ml of saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated, 100 ml of hexane was added to thus precipitated crystals, and the mixture was stirred under ice-cooling and then filtered. The thus collected crystals were washed with 30 ml of cold hexane and air-dried to give 29.8 g of the title compound (III) (GC purity 93%). The yield was 70%. Melting point; 104.9°C - 108.3°C ¹H-NMR δ (CDCl₃); 1.41 (3H, t), 1.3 - 1.6 (1H, m), 2.0 - 2.2 (1H, m), 3.91 (2H, t), 4.2 (2H, m), 4.39 (2H, q), 5.75 (1H, s), 7.43 (1H, dd), 7.5 - 7.6 (2H, m), 7.65 (1H, d)

References:

EP949243,1999,A1