N'-cyclopentylethane-1,2-diamine

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of cyclopentanone (2.000 mL, 22.6 mmol), ethylenediamine (10.860 g, 180.7 mmol), acetic acid (10.345 mL, 180.7 mmol), and 4 {acute over (Å)} molecular sieves (10 g) in anhydrous methanol (113 mL) was added sodium cyanoborohydride (2.839 g, 45.2 mmol). The mixture was stirred for 48 hrs, filtered to remove the solids, and concentrated in vacuo. The residue was dissolved in 3 N aqueous sodium hydroxide (150 mL) and extracted with methylene chloride (3×300 mL). The combined organic layers were washed with basic saturated aqueous sodium chloride, dried (anhydrous sodium sulfate), filtered, and concentrated to give the crude product. The material was vacuum distilled to give the desired product as a clear liquid (1.0 g, 35%). 1H NMR (300 MHz, CDCl3) δ 3.08-2.99 (quint, 1H, J=6.8 Hz), 2.80-2.76 (t, 2H, J=5.9 Hz), 2.65-2.61 (t, 2H, J=5.9 Hz), 1.87-1.77 (m, 2H), 1.72-1.60 (m, 2H), 1.57-1.46 (m, 2H), 1.35-1.24 (m, 5H). filtered to remove the solids concentrated in vacuo The residue was dissolved in 3 N aqueous sodium hydroxide (150 mL) extracted with methylene chloride (3×300 mL) The combined organic layers were washed with basic saturated aqueous sodium chloride dried (anhydrous sodium sulfate) filtered concentrated to give the crude product distilled