Triacetoxyperiodinane → 3-Bromo-4-iodobenzaldehyde

Participants

Reaction Conditions

Reaction Steps

A solution of (3-bromo-4-iodophenyl)methanol (Preparation 24, 3.1 g, 9.9 mmol) in CH2Cl2/water (2:1, 225 mL) was treated with NaHCO3 (915 mg, 10.9 mmol), NaBr (1060 mg, 10.2 mmol) and TEMPO free radical (40 mg, 0.2 mmol). The resulting mixture was cooled to 0° C. and NaOCl solution (0.8 mL, 10% aqueous) was added dropwise. The reaction mixture was left to come to room temperature while stirring. TLC after 30 minutes showed approximately 50% conversion to less polar spot. Sequence repeated using same equivalent of reagents. TLC 25:75 EtOAc:heptane still showed unreacted starting material. The reaction mixture was separated and the organic phase was treated with 1.0× Dess-Martin periodinane (2.1 g, 4.9 mmol) while stirring. TLC after 10 minutes showed complete conversion to less polar spot. The organic phase was washed with sat NaHCO3, dried over Na2SO4, filtered and evaporated to give an orange solid. The crude material was chromatographed (80 g Redi-Sep column) eluting from 100% heptane to 50:50 EtOAc/heptane to give the intermediate (2.7 g, 87%) as a white solid. 1HNMR (CDCl3): 9.94 (1H), 8.10 (2H), 7.50 (1H).

Provenance & Evidence