2-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 2-(3,5-Dichloro-2-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Participants

Reaction Steps

1-Bromo-3,5-dichloro-2-methoxybenzene (Preparation 25, 4.4 g, 17.5 mmol) in 95 ml diethylether was cooled to −78° C. under nitrogen. tBuLi (10 ml, 35.16 mmol) was added dropwise and the reaction stirred for 15 minutes. 2-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.58 g, 29 mmol) was added and the reaction stirred at −78° C. for 1 hour before pouring the reaction into 50 ml ice cold ammonium chloride (aqueous). The product was extracted with diethylether (3×30 ml), the combined organic layers were washed with water (50 ml) and brine (2×25 ml), dried over sodium sulphate, and concentrated in vacuo to afford a yellow oil. This was purified using silica gel column chromatography (heptane:ethyl acetate 9:1) to furnish a yellow oil, 4.5 g

Provenance & Evidence