Water → P-(4-amino-1,1,1-trifluoro-but-2-yl)-P-methyl-phosphinic acid hydroiodide

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Reaction Steps

To a mixture of 825 mg of diisopropylaminomethyl-polystyrene in 5 ml of acetonitrile are added 69.4 mg (0.2 mmol) of ethyl P-(4-amino-1,1,1-trifluoro-but-2-yl)-P-methyl-phosphinate trifluoroacetate while stirring at 25°. To this mixture are added 0.09 ml (0.7 mmol) of trimethylsilyl bromide. After stirring for 1 hour at 25°, the mixture is filtered and 299.78 mg (2 mmol) of sodium iodide and 217.28 mg (2 mmol) of trimethylsilyl chloride are added to the filtrate which is then stirred for 16 hours at 25°. The sodium chloride precipitated is filtered off and the filtrate is evaporated under reduced pressure to dryness. The crude product is dissolved in 2 ml of acetonitrile. 15 mg (0.83 mmol) of water are added to the resulting solution. After stirring for 1 hour at 25°, the solution is evaporated under reduced pressure to dryness and chromatographed on 50 g of Opti-Up® C12 with acetonitrile as eluent to remove a small amount of the starting material. After re-eluting with water, the product-containing fractions are combined and evaporated under reduced pressure to give P-(4-amino-1,1,1-trifluoro-but-2-yl)-P-methyl-phosphinic acid hydroiodide as an oil; 1H-NMR spectrum: δ=3.20 ppm (m, 2H), 2.67 ppm (m, 1H), 2.15 (m, 2H), 1.42 ppm (d, 3H).

Provenance & Evidence