9H-fluoren-9-ylmethyl piperazine-1-carboxylate;hydrochloride

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

Procedure: Piperazine-1-carboxylic acid 9H-fluoren-9-ylmethyl ester hydrochloride (0.67 g, 1.93 mmole) was dissolved in methanol (5 ml), treated with diisopropylamine (0.34 m], 1.93 mmole) and allowed to stir at room temperature for 5 minutes. The product from Step 1 (0.50 g, 2.89 mmole) and sodium cyanoborohydride (133 mg, 2.12 mmole) were added and the mixture stirred under argon for 18 hours. The solvent was removed in vacuo and the residue was dissolved in dichloromethane, washed with saturated sodium bicarbonate solution, dried over magnesium sulfate and concentrated in vacuo. The residue was purified by column chromatography eluting with ethyl acetate/hexane (1:1) to afford the title compound (0.71 g). 1H NMR (CDCl3) δ 7.78-7.75 (2H, d), 7.59-7.56 (2H, d), 7.41-7.31 (4H, m), 4.52-4.43 (2H, d), 4.27-4.20 (1H, t), 3.51-3.42 (4H, br m), 3.25-3.15 (2H, m), 2.45-2.35 (6H, m), 1.72-1.60 (2H, m), 1.45 (9H, s). the mixture stirred under argon for 18 hours The solvent was removed in vacuo the residue was dissolved in dichloromethane washed with saturated sodium bicarbonate solution dried over magnesium sulfate concentrated in vacuo The residue was purified by column chromatography eluting with ethyl acetate/hexane (1:1)