Water → 3-(2,2-Diethoxyethoxy)-5,6-difluoro-N-(2-fluoro-4-iodophenyl)-2-nitroaniline

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Reaction Conditions

Reaction Steps

For large scale synthesis, 2,2-diethoxyethanol was added dropwise into a suspension of 60% sodium hydride in 5 L of THF at 1-2° C. over 30 minutes and then stirred at 0-5° C. for 1.5 hours. A solution of 750 g of 2,3,5-trifluoro-N-(2-fluoro-4-iodophenyl)-6-nitroaniline in 2.25 L of THF was then added dropwise into the above suspension at 0-5° C. After the addition, the purple solution was stirred at room temperature for 2 days and 17 hours. HPLC analysis showed 4.1% remaining of 2,3,5-trifluoro-N-(2-fluoro-4-iodophenyl)-6-nitroaniline. 150 mL of water was added very slowly (gas generated) into the pre-cooled solution at 10° C. The solution was then concentrated to dryness. The resultant oil was then suspended in 5 L of heptanes and seeded with pure 3-(2,2-diethoxyethoxy)-5,6-difluoro-N-(2-fluoro-4-iodophenyl)-2-nitroaniline crystal and stirred for 30 minutes. After 1 hour of stirring, the precipitate was filtered and dried to yield 520 g (54.3%) of product with 96.4% purity. Further product was available in the mother liquor. 1H NMR (CDCl3, 400 MHz): δ 7.42 (dd, 1H), 7.34 (d, 1H), 6.87 (bs, 1H), 6.56-6.67 (m, 2H), 4.79 (t, 1H), 4.06 (d, 2H), 3.74-3.82 (m, 2H), 3.59-3.66 (m, 2H); 1.24 (t, 6H).

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