Sodium Bicarbonate → Benzyl 4-((2-amino-4-(5-bromo-4-(2-ethoxy-2-oxoethyl)thiophene-2-carbonyl)phenyl)ethynyl)benzoate

Participants

Reaction Steps

To a solution of 3 (450 mg, 0.71 mmol) in EtOAc (10 mL) was added stannous chloride dihydrate (642 mg, 2.84 mmol). The resulting mixture was refluxed for one hour under N2. The reaction mixture was poured onto ice (5 g), and basified with saturated NaHCO3 solution to pH 8. The white milky mixture was filtered through a Celite pad to remove tin oxides. The organic layer from the filtrate was dried over MgSO4, filtered, and then concentrated in vacuo. MPLC purification (Hex:EtOAc/4:1) of the crude product gave the desired intermediate benzyl 4-((2-amino-4-(5-bromo-4-(2-ethoxy-2-oxoethyl)thiophene-2-carbonyl)phenyl)ethynyl)benzoate as a yellow foam (450 mg, 95%). 1H NMR (400 MHz, CDCl3) δ 8.07 (d, J=8.0 Hz, 2H), 7.60 (d, J=8.0 Hz, 2H), 7.51-7.36 (m, 7H), 7.22-7.18 (m, 2H), 5.38 (s, 2H), 4.18 (q, J=7.2 Hz, 2H), 3.64 (s, 2H), and 1.27 (t, J=7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 186.72, 169.84, 166.01, 148.31, 143.21, 138.58, 136.12, 136.05, 135.39, 132.55, 131.71, 130.02, 129.98, 128.90, 128.62, 128.51, 127.71, 122.93, 118.70, 114.66, 111.47, 96.66, 88.41, 67.21, 61.63, 53.75, 35.32, and 14.44.

Provenance & Evidence