Sodium Sulfite → Benzaldehyde, 2-bromo-3-(phenylmethoxy)-

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Reaction Conditions

Reaction Steps

(2-bromo-3-benzyloxy-benzyl alcohol (251 g, 0.86 mol) was dissolved in THF (300 mL) and sodium bromide (13.2 g, 0.128 mol) added. The reaction mixture was cooled to 0° C. and TEMPO (0.67 g, 4.28 mmol) was added followed by a freshly prepared (0° C.) solution of sodium bicarbonate (10.8 g, 0.128 mol) in 1 liter of commercial Chlorox® bleach. This was stirred rapidly at 0° C. for 3 h and sodium sulfite added. Any precipitated solids were dissolved upon addition of deionized water. The organics were separated and the aqueous layer extracted with ethyl acetate. The combined organics were washed with brine, dried (MgSO4) and concentrated. The residue was cooled in an ice bath and the precipitated solids collected by filtration to give 2-bromo-3-benzyloxybenzaldehyde (224 g, 90%): mp 125°-6° C. The above prepared aldehyde (215 g) was combined in toluene (200 mL) with 1,3-propane diol (107 mL, 1.48 mol) and pTSA.H2O (1.6 g) and heated at the reflux temperature with azeotropic removal of water via a Dean-Stark trap. After 1.5 h the reaction mixture was cooled and washed with saturated sodium bicarbonate and brine. The organics were separated, dried (MgSO4) and evaporated. The residue was crystallized from methanol to afford the title compound as a white solid (248 g, 96%): mp 73°-4° C.

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