Chlorotrimethylsilane → HCID 67253499, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of zinc dust (1.03 g, 15.75 mmol) in THF (15 mL) was added trimethylsilyl chloride (1.2 mL, 9.45 mmol) at 40° C. The mixture was heated to 55° C. and stirred for 15 minutes. After cooling down to 37° C., ethyl bromoacetate (1.74 mL, 15.75 mmol) was slowly added to the reaction mixture at 37-40° C. After addition, the resulting mixture was cooled to room temperature over 30 minutes. This solution was added to a solution of 4-(3-benzyloxy-phenoxy)-2-methyl-6-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-benzaldehyde (1.4 g, 3.75 mmol) in THF (50 mL) at −78° C. The mixture was allowed to warm to room temperature over 3 hours, quenched with saturated NH4Cl (10 mL) and extracted with EtOAc (2×25 mL). The organic extracts were washed with brine, dried and concentrated in vacuo. The residue was purified by silica gel flash column chromatography (hexane:EtOAc 50:50) to give [6-(3-benzyloxy-phenoxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (0.93 g, 68%). 1H NMR (400 MHz, DMSO): δ 9.22 (s, 1H), 7.41-7.24 (m, 6H), 7.07 (s, 1H), 6.95 (s, 1H), 6.77 (d, J=8.0 Hz, 1H), 6.61 (s, 1H), 6.51 (d, J=6.8 Hz, 1H), 5.48 (d, J=7.2 Hz, 1H), 5.05 (s, 2H), 4.02 (q, J=7.2 Hz, 2H), 3.10 (dd, J=2.4, 15.6 Hz, 1H), 2.30-2.27 (m, 1H), 2.26 (s, 3H), 1.11 (t, J=6.8 Hz, 3H). MS (ESI) m/z=433 [M+H]+.

Provenance & Evidence