Hexamethyldisilazane → 3-Isopropoxy-5-(4-phosphono-phenoxy)-benzoic acid 2-trimethylsilanyl-ethyl ester

Participants

Reaction Steps

To a solution of 3-[4-(diisopropoxy-phosphoryl)-phenoxy]-5-isopropoxy-benzoic acid 2-trimethylsilanyl-ethyl ester (5.0 g, 9.30 mmol) in CH2Cl2 (100 mL) was added HMDS (31.7 Ml, 149 mmol), and TMS-Br (9.8 mL, 74.5 mmol). The mixture was stirred at rt for 16 h. The solvent was evaporated and the residue was diluted with water and acidified to pH 2-3 with aqueous HCl. Extracted into EtOAc (2×). The extract was washed with dilute HCl, water, and brine. Dried (MgSO4) and evaporated to provide 2.74 g of 3-Isopropoxy-5-(4-phosphono-phenoxy)-benzoic acid 2-trimethylsilanyl-ethyl ester. 1H NMR (500 MHz, DMSO-d6): δ 7.71 (dd, J=13, 9 Hz, 2H), 7.22 (dd, J=3, 2 Hz, 1H), 7.11 (dd, J=9, 3 Hz, 2H), 7.03 (dd, J=3, 2 Hz, 1H), 6.92 (t, J=3 Hz, 1H), 4.67 (m, 1H), 4.34 (t, 2H), 1.27 (d, J=6 Hz, 6H), 1.05 (t, 2H), 0.01 (s, 9H).

Provenance & Evidence