反应详情

温度

25 °C

N′-Allyl-N′-cyclobutyl-hydrazine hydrogen chloride (288 mg, 1.77 mmol) was dissolved in methanol (20 mL). 2-Oxo-cyclopentanecarboxylic acid ethyl ester (0.26 mL, 1.77 mL), sodium acetate (290 mg, 3.54 mmol), sodium cyanoborohydride (222 mg, 3.54 mmol) and 4 Å molecular sieves (400 mg) were added sequentially. The reaction was stirred at 25° C. for 18 h before it was quenched via the addition of saturated aqueous sodium bicarbonate solution (20 mL). The mixture was 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; 0-30% ethyl acetate in hexanes) afforded the desired product, 2-(N′-allyl-N′-cyclobutyl-hydrazino)-cyclopentanecarboxylic acid ethyl ester (333 mg, 1.25 mmol, 71%), as a white powder. 1H NMR (400 MHz, CDCl3) δ: 1.25-1.38 (2.2H, m), 1.60-1.68 (3.1H, m), 1.74-1.88 (5.2H, m), 1.94-2.06 (4.8H, m), 2.14-2.21 (3.6H, m), 3.42 (2.5H, d, J=6.8 Hz), 3.51-3.58 (1.3H, m), 3.64-3.69 (0.4H, m), 3.76-3.80 (0.5H, m), 4.10-4.20 (1.2H, m), 4.36-4.41 (0.3H, m), 5.36 (2.2H, bs), 5.45-5.51 (2.7H, m), 5.74-5.85 (1H, m). LC-MS (ESI) calcd for C15H26N2O2 266.38, found 267.2 [M+H+].

1. customwas quenched via the addition of saturated aqueous sodium bicarbonate solution (20 mL)
2. extractionThe mixture was extracted with ethyl acetate (3×20 mL)
3. dry with materialdried over magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customto afford a yellow oil
7. customPurification by flash column chromatography (Teledyne Isco RediSep Column; 0-30% ethyl acetate in hexanes)