Triethylamine → [5-Methoxy-3-methyl-2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-benzyloxy]-acetic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of (2-bromo-5-methoxy-3-methyl-benzyloxy)-acetic acid tert-butyl ester ((Example 192: step d) 1.19 g, 3.45 mmol) in dioxane (10 mL) was treated with PdCl2(PPh3)2 (0.242 g, 0.345 mmol) and triethylamine (2.88 mL, 20.7 mmol). 4,4,5,5-Tetramethyl-1,3,2-dioxaborolane (1.00 mL, 6.89 mmol) was added slowly and the mixture heated to 80° C. 15 h. The reaction was diluted with EtOAc and washed with brine (2×50 mL). The organic layer was dried over MgSO4 and concentrated in vacuo. Silica gel chromatography (25% EtOAc in hexanes) afforded the product [5-methoxy-3-methyl-2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-benzyloxy]-acetic acid tert-butyl ester (0.793 g, 58%) as a brown oil. The crude material was used directly in the next reaction.

Provenance & Evidence