Triethylamine → (R)-1-[4-(4-Oxazolo[5,4-c]pyridin-2-yl-piperazin-1-yl)-pyrimidin-2-yl]-ethyl butyrate

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Reaction Steps

To a solution of 2-(1-piperazinyl)oxazolo[5,4-c]pyridine (775 mg, 3.8 mmol; J. Org. Chem. 1995, 60, 5721) in isopropanol (38 mL) was added (R)-1-(4-chloro-pyrimidin-2-yl)-ethyl butyrate (prepared according to the method of Preparation Seven, 868 mg, 3.8 mmol) followed by triethylamine (1.6 mL, 11.4 mmol). This mixture was stirred at reflux overnight, cooled to room temperature, and evaporated. The residue was diluted with saturated aqueous sodium bicarbonate and extracted with chloroform (3×). The combined organic extracts were dried over sodium sulfate, filtered, evaporated, and purified by flash column chromatography (2×; 3% methanol/chloroform then 6→8% methanol/ethyl acetate, where used herein, the arrow symbol, →, indicates a gradient) to give 1.2 g (79%) of the title compound of Example 2, Step A as a pale yellow oil which solidified upon standing. 1H NMR (CDCl3, 250 MHz) δ 8.57 (s, 1H), 8.39 (d,1H), 8.28 (d, 1H), 7.30 (d, 1H), 6.44 (d, 1H), 5.70 (q, 1H), 3.85 (s, 8H), 2.42 (t, 2H), 1.78-1.61 (c, 2H), 1.60 (d, 3H), 0.98 (t, 3H); MS (APCI) 397 (MH+).

Provenance & Evidence