Triethylamine → 2,2-Dimethyl-propionic acid 1H-indazol-6-yl Ester

関与物質

反応手順

To a solution of 1H-indazol-6-ol (0.88 g, 6.6 mmol) in dichloromethane (10 ml) at room temperature was added triethylamine (0.98 ml, 7.0 mmol) and DMAP (0.05 g) followed by trimethylacetyl chloride (0.82 ml, 6.6 mmol). After stirring for 1 h, the mixture was diluted with saturated aqueous solution of ammonium chloride (20 ml) and extracted with ethyl acetate (3×50 ml). The combined extracts were washed with brine (10 ml), dried (MgSO4), and evaporated to a residue which was purified by chromatography (silica, 10% to 20% ethyl acetate in hexane) to give an oil (1.1 g, 76%): 1H NMR (CDCl3) δ 8.15 (d, J=0.8 Hz, 1H), 8.01 (s, 1H), 7.75 (s, 1H), 7.58 (d, J=8.6 Hz, 1H), 7.01 and 6.96 (dd, J=2.0 and 8.6 Hz, 1H), 1.59 (s, 9H); MS(ES) m/z 219 (M+).

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