Benzaldehyde → {4-[4-(2-Benzylaminoethoxy)phenyl]butyl}carbamic acid benzyl ester

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Reaction Steps

Benzyaldehyde (0.74 ml, 7.31 mmol) was added to a solution of 4-[4-(2-aminoethoxy)phenyl]butylcarbamic acid benzyl ester (15) (5.00 g (˜50% purity by NMR), 7.30 mmol) dissolved in anhydrous dichloroethane (50 mL). The resulting solution was stirred at ambient temperature for 7 h. Sodium triacetoxyborohydride (4.10 g, 19.35 mmol) was added slowly and the reduction continued for 60 h. The reaction was quenched with aqueous sodium bicarbonate (50 mL) and then extracted with ethyl acetate (3×25 mL). The combined organic extracts were washed sequentially with water and brine, and dried over anhydrous sodium sulfate. A white solid precipitated out during the drying and collected by dissolving it in dichloromethane and then filtering off the solid sodium sulfate. The filtrate was concentrated and dried under vacuum to give 16 (1.35 g, 43%) as a white solid: 1H NMR (500 MHz, CDCl3) δ 1.45-1.62 (m, 4H), 2.54 (t, 2H), 3.07-3.22 (m, 4H), 3.88 (s, 2H), 4.10 (t, 2H), 4.73 (br, 1H), 5.09 (s, 2H), 6.79 (d, 2H), 7.04 (d, 2H), 7.28-7.39 (m, 10H); m/z (ESI) 433 [C27H32N2O3+H]+.

Provenance & Evidence