Methyl iodide → Tert-butyl 4-(2-(methyl(thiazol-2-yl)amino)-2-oxoethyl)piperazine-1-carboxylate

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Reaction Steps

To a solution of tert-butyl 4-(2-oxo-2-(thiazol-2-ylamino)ethyl)piperazine-1-carboxylate (0.056 g, 0.17 mmol) in anhydrous DMF (1.0 mL) cooled into an ice-bath under argon was added sodium hydride (60% dispersion; 7.8 mg, 0.19 mmol). Stirring was continued at 0° C. for ˜2 min and then methyl iodide (0.048 g, 0.34 mmol) was added with the aid of DMF (0.4 mL), the reaction mixture was stirred for 1.5 h under argon, and then partitioned between ethyl acetate (30 mL) and brine (30 mL). The aqueous layer was extracted with ethyl acetate (30 mL), and the combined organics were washed with brine (2×30 mL), dried (Na2SO4), and concentrated in vacuo. Purification by chromatography (10 g isolute column, 80% ethyl acetate in petroleum ether 60-80° C.) afforded the title compound as an oil (0.036 g, 62%); 1H-NMR (500 MHz, DMSO-d6) 1.40 (s, 9H, C(CH3)3), 3.33 (s, 4H, piperazine N(CH2)2), 3.58 (s, 2H, NCH2CO), 3.68 (s, 3H, CH3), 7.27 (d, J=3.5 Hz, 1H, thiazole H), 7.53 (d, J=3.5 Hz, 1H, thiazole H);

Provenance & Evidence