Methyl iodide → 1-Methyl-3-oxo-2-quinoxalin-2-yl-1,2,3,4,6,7-hexahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

To a solution of 3-oxo-2-quinoxalin-2-yl-1,2,3,4,6,7-hexahydro-pyrazolo[4,3-c]pyridine-5-carboxylic acid tert-butyl ester (prepared according to the method of Example 75, Step A, 250 mg, 0.68 mmol) in dimethylformamide (2 mL) at 0° C. with stirring under nitrogen was added sodium hydride (60% dispersion in mineral oil, 41 mg, 1.02 mmol). After 10 min, iodomethane (51 μL, 0.82 mmol) was added. This mixture was allowed to stir at 0° C. for 2 h, quenched by addition of saturated aqueous sodium bicarbonate and extracted with ethyl acetate (4×). The combined organic extracts were dried over sodium sulfate, filtered, evaporated, and purified by flash column chromatography (40% ethyl acetate/hexanes) to give 164 mg (63%) of the title compound of Example 75, Step B as a yellow foam. 1H NMR (CDCl3, 250 MHz) δ 9.71 (s, 1H), 8.15 (dd, 1H), 8.02 (m, 1H), 7.80-7.70 (c, 2H), 4.29 (s, 2H), 4.14 (t, 2H), 3.79 (s, 3H), 2.72-2.67 (c, 2H), 1.50 (s, 9H); MS (APCI) 382 (MH+).

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