Acetyl chloride → 3-(4-Benzyloxy-2-iodo-5-methoxyphenyl)-5-methyl-[1,2,4]oxa-diazole

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Reaction Steps

To a mixture of 4-benzyloxy-N-hydroxy-2-iodo-5-methoxy-benzamidine (reference example 3-1) (35 g), triethylamine (31 mL) and tetrahydrofuran (31 mL) was added acetyl chloride (8.2 mL) under ice-bath cooling. The mixture was stirred at the same temperature for 1 hour. Insoluble materials were removed by filtration. To the filtrate was added tetrabutylammonium fluoride (1 mol/L tetrahydrofuran solution, 89 mL). After stirring at the same temperature for 2 hours, water and ethylacetate were added to the mixture. The separated organic layer was washed with 1 mol/L hydrochloric acid, a 1 mol/L aqueous solution of sodium hydroxide, an aqueous solution of sodium bicarbonate and brine successively, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was triturated with methanol to give the title compound (31.5 g).

Provenance & Evidence