2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → Tert-butyl isopropyl(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiazol-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 5-bromothiazol-2-yl(isopropyl)carbamate (7.5 g, 23.3 mmol) in THF (50 mL) was added n-butyllithium (1.6 M in hexane, 21.8 mL) dropwise at −78° C. The solution turned orange. The solution was stirred at −78° C. for minutes before 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (6.49 g, 34.9 mmol) was added dropwise. The mixture was stirred at −78° C. for 2 hours then warmed to room temperature. The reaction was quenched with 1:1 ammonium chloride/water (50 mL). The resulted mixture was extracted with ethyl acetate (100 mL). The organic layer was separated, washed with water, brine and concentrated. To the brown solid residue was added hexane (30 mL). The mixture was filtered and the filter cake was washed with hexane (20 mL) and dried to give as a yellow solid (4.17 g, 48% yield). LCMS (Conditions C): 3.21 min (RT); (M+H)+=247.12 (40%), 245.12 (50%), 233.10 (75%), 231.10 (100%). 1H NMR, 400 MHz, CDCl3: δ 7.95 (s, 1 H), 5.37 (m, 1 H), 1.60 (s, 9 H), 1.44 (d, 6.7 Hz, 6 H), 1.34 (s, 12 H).

Provenance & Evidence