Tetramethyl m-trimethylsilylphenyl-1-hydroxy-ethylidenebis(phosphonate) → HCID 178527095, compound

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Reaction Steps

From 17: To a solution of the phosphonate 17 (0.289 g, 1 mmol) in THF (10 ml) was added diethyl chlorophosphate (0.259 g, 1.5 mmol) and Et3N (0.30 g, 3.0 mmol) at 0° C., After 20 min the cooling bath was removed and the reaction mixture was stirred for 48 h. The mixture was extracted with CH2Cl2, the organic phase was washed with water, 10% H3PO4, then brine and dried (MgSO4). Filtration and evaporation afforded 0.25 g (59%) of a pale yellow colored liquid. From 18: Sodium diethyl phosphite (18 mmol) was added to a solution of the phosphonate 18 (5.51 g, 15 mmol) in THF (60 ml) at 0° C., After 2 h the reaction was quenched by addition of saturated NH4Cl (aq) (1.5 ml) and the mixture was concentrated under reduced pressure. The residue was extracted with CH2Cl2, the organic phase was washed with water, then brine and dried (MgSO4). Filtration and evaporation yielded the crude product (6.45 g), which was purified by flash chromatography (silica, AcOEt/MeOH gradient) to give 4.64 g (73%) of the phosphate phosphonate 19. From 22a: Sodium diethyl phosphite (3.5 mmol) was added to a solution of the phosphonate 22a (0.91 g, 2 mmol) in THF (10 ml) at 0° C., The resulting orange mixture was stirred for 2 h and quenched by addition of saturated NH4Cl (aq) (1 ml). The product mixture was extracted with CH2Cl2, the organic phase was washed with water, then brine and dried (MgSO4). Filtration and evaporation gave 0.76 g (89%) of 19 as a yellow colored liquid. IR (film): 2910, 1535, 1350, 1290 and 1025; 1H NMR (200 MHz, CDCl3): δ1.23 (12H, m), 3.99 (8H, m), 5.64 (1H, dd, J=3, 11 Hz) and 7.87 (4H, m); 13C NMR (50 MHz, CDCl3): δ16.6 (m), 64.5 (m), 71.9 (d, J=7 Hz), 75.3 (d, J=7 Hz), 122.5, 123.8, 128.4, 129.5, 133.7 and 148.3; HR-MS (EI): m/e 425.1010 (M+C15H25NO9P2 requires 425.1006).

Provenance & Evidence