Ethylenediaminetetraacetic Acid → Butyl 2-(isoquinolin-6-yl)acetate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A dry, 25 mL, 1 neck round bottom flask was charged with a 0.5 M Et2O solution of Zincate 2 (10.00 ml, 5.0 mmol, Reike Metals), and concentrated in vacuo. The vacuum was released with nitrogen, and the flask was charged with a stirbar, 5 mL dry THF, fitted with a reflux condenser and an Ar inlet. Upon dissolution of the solids, 6-bromoisoquinoline (0.516 g, 2.5 mmol) and tetrakis(triphenylphosphine)palladium (0.24 g, 0.21 mmol) was added. The solution was heated with an 80° C. oil bath for 5 h, and cooled. The solution was treated with 30 mL of 10% aqueous EDTA (pH adjusted to 6.1 with NaOH), and stirred for 1 h. A precipitate had formed that was removed by filtration of the biphasic solution through a sintered glass funnel and discarded. The filtrate was concentrated to ˜35 mL, and extracted with DCM (4×30 mL). The combined extracts were washed with water (1×30 mL), and the water was back-extracted with DCM (1×10 mL). The DCM layers were dried over MgSO4, and the resultant slurry filtered through a sintered glass funnel. The filtrate was concentrated in vacuo. The residue was dissolved in 10 mL DCM and treated with Si-carbonate (Silicycle, 5.5 g, 3.7 mmol). The slurry was swirled occasionally for 1 h, and filtered through a 0.22 uM PTFE membrane. The silica was washed with DCM (4×20 mL), and the combined filtrates were concentrated in vacuo. The residue was purified in three injections using a Waters Spherisorb S5 column (PN PSS830195, 20×250 mm, 60 Å pore, 5 μm particle size); flow=20 mL/min; A=DCE, B=EtOH; isocratic at 5% B. A band that eluted from 3.9 to 5.9 minutes was isolated. The solvent was removed in vacuo to afford ten-butyl 2-(isoquinolin-6-yl)acetate.

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