Acetic Acid → [2-(Benzyl-{4-[6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-2-methyl-but-2-enyl}-amino)-ethyl]-phosphonic Acid Diethyl Ester

Participants

Reaction Steps

A solution of (2-{4-[6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-2-methyl-but-2-enylamino}-ethyl)-phosphonic acid diethyl ester (30 mg, 0.055 mmol), benzaldehyde (5.6 μL, 0.055 mmol), and sodium triacetoxyborohydride (23 mg, 0.11 mmol) was stirred with acetic acid (15.7 μL, 0.28 mmol) in DMF (0.5 mL) at room temperature over night. The reaction was quenched with a 10% aqueous Na2CO3 solution and the product was extracted with EtOAc. The organic layer was dried and concentrated under reduced pressure. The product was purified by RP HPLC using a C18 column with a gradient of H2O, 0.1% TFA-acetonitrile, 0.1% TFA to provide 15 mg of the product (43%) as a clear gel. 1H NMR (300 MHz, CDCl3) δ 0.02 (s, 9H), 1.18-1.25 (m, 2H), 1.24 (t, 6H, J=7 Hz), 1.86 (s, 3H), 1.88-2.02 (m, 2H), 2.16 (s, 3H), 2.65-2.74 (m, 2H), 3.93 (s, 2H), 3.46 (br d, 4H, J=7 Hz), 3.76 (s, 3H), 4.00 (pent, 4H, J=7 Hz), 4.25-4.34 (m, 2H), 5.11 (s, 2H), 5.34-5.43 (m, 1H), 7.18-7.33 (m, 5H) ppm; 31P (121.4 MHz, CDCl3) δ 30.9 ppm; MS (m/z) 632.4 [M+H]+, 654.3 [M+Na]+.

Provenance & Evidence