Potassium Carbonate → 4-Ethynyl-1-iodo-2-methoxybenzene

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Reaction Steps

4-Iodo-3-methoxy-benzaldehyde (27.26 g, 104 mmol) and potassium carbonate (28.8 g, 208 mmol) were placed in a 2000-mL flask under nitrogen and methanol (1317 ml) was added. To the yellowish suspension was added (1-diazo-2-oxo-propyl)-phosphonic acid dimethyl ester (23.98 g, 125 mmol) in 20 mL MeOH via syringe. The reaction mixture was stirred at room temperature for 16 h giving a yellow solution. LCMS showed complete conversion to product. The yellow suspension was concentrated down to approximately 200-300 mL, then aqueous sodium hydrogen carbonate (saturated, 100 mL) was added and the mixture was diluted with diethyl ether (450 mL). The combined organic fractions were washed with brine (saturated, 2×10 mL), dried (MgSO), filtered and the solvent was evaporated under reduced pressure. The residue was dried on high vacuum over night to give a yellow solid. The crude material was purified on silica gel (330 g column; gradient to 30% EtOAc/heptane) and the resulting oil was dried under high vacuum to afford 4-ethynyl-1-iodo-2-methoxy-benzene (22.7 g) a semi-solid yellow material which was pure by NMR.

Provenance & Evidence