Dimethyl(methylene)ammounium iodide → N,N-Dimethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole-3-methanamine

Participants

Reaction Steps

To a suspension of Eschenmoser's salt (0.91 g, 4.9 mmol) in CH3CN (3 mL) and HOAc (1.5 mL) at rt was added a solution of 5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-indole (1.0 g, 4.1 mmol) in CH3CN (3 mL) dropwise over about 10 min. After about 2 hours, the reaction was quenched with saturated aqueous NaHCO3 and extracted with CH2Cl2 (3×15 mL). The combined organic layers were washed with brine, dried over Na2SO4, decanted, and concentrated to give crude N,N-Dimethyl-1-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indol-3-yl]methanamine (0.60 g, 50%); RP-HPLC (Table 1, Method g) Rt 1.39 min; 1H NMR (d6-DMSO, 400 MHz) δ11.26 (br s, 1H), 8.07 (s, 1H), 7.44 (d, J=8.2 Hz, 1H), 7.37 (m, 2H), 3.92 (s, 2H), 2.40 (s, 6H), 1.31 (s, 12H).

Provenance & Evidence