1,2-Dichloroethane → Hydrochloric Acid

Participants

Reaction Steps

A suspension of the ketone 198b (2.33 g, 5.89 mmol, 1.0 eq), 4-(trifluoromethyl)benzylamine (0.98 g, 5.59 mmol, 0.95 eq) and NaBH(OAc)3 (1.62 g, 7.66 mmol, 1.3 eq) in 1,2-dichloroethane (70 ml) was stirred for at r.t. After 3 days, it was poured in CH2Cl2 (600 ml), rinsed with sat. aq. NaHCO3 (100 ml), dried (MgSO4), and concentrated. The colourless oily crude was dissolved in MeOH (100 ml) and treated with 2 ml fuming HCl (pre-diluted with 20 ml MeOH). After 30 seconds, a white precipitate started appearing. This was collected after 10 minutes by filtration to give the desired product as its HCl salt, and in excellent purity (1.6 g, 47% yield). Concentration of the filtrate to 10 ml afforded more precipitate (0.6 g, 17% yield). Mp=288-289° C., 1H NMR (DMSO-d6) δ 12.5 (s, 1H), 10.38 (t, J=6.0 Hz, 1H), 9.90-9.70 (br.s, 1.5H), 8.37 (dd, J=7.2 & 2.1 Hz, 1H), 7.85-7.70 (m, 5H), 7.48 (d, J=3.7 Hz, 1H), 7.16 (d, J=3.8 Hz, 1H), 6.49 (t, J=6.8 Hz, 1H), 4.73 (d, J=5.8 Hz, 2H), 4.24-4.16 (br s, 2H), 3.66 (d, J=11.7 Hz, 2H), 3.20-3.05 (br. m, 1H), 2.39 (t, J=11.3 Hz, 2H), 2.19 (d, J=10.7 Hz, 2H), 1.76 (qd, J=11.5, 3.2 Hz, 2H). 19F NMR (DMSO-d6)−61.64.

Provenance & Evidence