tert-Butoxy bis(dimethylamino)methane → tert-butyl 3-[(dimethylamino)methylene]-4-oxotetrahydro-1(2H)-pyridinecarboxylate

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Reaction Steps

To a solution of 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (prepared according to the method of Example 101, Step A, 4.0 g, 20.0 mmol) in dimethylformamide (40 mL) was added tert-butoxybis(dimethylamino)methane (4.35 mL, 22 mmol). This mixture was stirred at reflux for 15 h, cooled to room temperature, diluted with water, and extracted with ethyl acetate (5×). The combined organic extracts were washed with water (3×) and brine (1×), dried over sodium sulfate, filtered, and evaporated to give 3.64 g (72%) of the title compound of Example 101, Step B as a brown oil that was sufficiently pure to carry on to the next step. 1H NMR (CDCl3, 400 MHz) δ 7.47 (s, 1H), 4.53 (s, 2H), 3.58 (t, 2H), 3.09 (s, 6H), 2.43 (t, 2H), 1.46 (s, 9H); MS (APCI) 255 (MH+).

Provenance & Evidence