Sodium hydride → Di-tert-butyl [2-(ethoxycarbonyl)-1-benzothien-6-yl]malonate

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Reaction Steps

Di-tert-butyl malonate (1.5 g, 6.93 mmol) was dissolved in THF (6 mL) and sodium hydride (60% dispersion in mineral oil, 0.28 g, 7.00 mmol) was added. The mixture was stirred for 10 minutes before adding Pd(PtBu3)2 (0.1 g, 0.196 mmol) and a solution of ethyl 6-bromo-1-benzothiophene-2-carboxylate (1.8 g, 6.31 mmol) in THF (12 mL). The resulting mixture was heated to reflux under N2 for 18 hours. Room temperature was attained, saturated NH4Cl (150 mL) was added and the products extracted into EtOAc (2×125 mL). The combined organic extracts were dried over MgSO4 and concentrated in vacuo. Purification of the residue by MPLC gave 1.27 g of desired product (pale yellow solid, 48%). 1H NMR (DMSO-d6) δ 8.17 (s, 1H), 8.01 (s, 1H), 7.99 (d, J=8.4 Hz, 1H), 7.45 (dd, J=8.4, 1.8 Hz, 1H), 4.83 (s, 1H), 4.33 (q, J=7.2 Hz, 2H), 1.40 (s, 18H), 1.31 (t, J=7.2 Hz, 3H).

Provenance & Evidence