Allyl bromide → N'-allyl-N'-cyclobutyl-hydrazinecarboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

N′-cyclobutyl-hydrazinecarboxylic acid tert-butyl ester (0.88 g, 4.72 mmol) was dissolved in ethanol (45 mL). Allyl bromide (0.82 mL, 9.44 mmol), potassium carbonate (0.65 g, 4.72 mmol), and lithium iodide (0.063 g, 0.47 mmol) were added sequentially. The reaction was stirred at reflux for 18 h. The mixture was cooled to 25° C., concentrated in vacuo, taken up in water (20 mL) and extracted with ethyl acetate (3×20 mL). The organic layers were combined, dried over magnesium sulfate, filtered, and concentrated in vacuo to afford a yellow oil. Purification by flash column chromatography (Teledyne Isco RediSep Column; 0-20% ethyl acetate in hexanes) afforded the desired product, N′-allyl-N′-cyclobutyl-hydrazinecarboxylic acid tert-butyl ester (0.98 g, 4.34 mmol, 92%), as a white powder. 1H NMR (400 MHz, DMSO-d6) δ: 1.36 (9H, s), 1.50-1.62 (2H, m), 1.82-1.88 (4H, m), 3.13 (2H, d, J=6.0 Hz), 3.34-3.39 (1H, m), 5.03 (1H, d, J=10.0 Hz), 5.14 (1H, d, J=16.8 Hz), 5.71-5.81 (1H, m), 7.59 (1H, bs). LC-MS (ESI) calcd for C7H14N2 (free hydrazine) 126.20, found 127.0 [M+H+].

Provenance & Evidence