Betahistine → Ammonia dichloromethane

Participants

Reaction Steps

A solution of the product of Example 9 (256 mg), methyl-(2-pyridin-2-yl-ethyl)-amine (143 mg), and acetic acid (0.06 mL) in DCM (4 mL) was treated with sodium triacetoxyborohydride (330 mg). After 16 h, the resulting mixture was treated with 10% sodium hydroxide (5 mL) and extracted with DCM (3×10 mL). The combined organic phases were dried (sodium sulfate) and evaporated. Chromatography of the residue (1–5% 2 M methanolic ammonia/DCM) gave the title compound as a colorless oil (325 mg). 1H NMR (400 MHz, CDCl3): 8.51 (m, 1H), 7.57 (m, 1H), 7.18–7.12 (m, 3H), 7.10 (m, 1H), 6.82 (d, J=8.6 Hz, 2H), 3.98 (t, J=6.3 Hz, 2H), 3.49 (s, 2H), 2.99 (m, 2H), 2.78 (m, 2H), 2.46 (m, 2H), 2.39 (br, 4H), 2.25 (s, 3H), 1.96 (m, 2H), 1.61–1.54 (m, 4H), 1.47–1.40 (m, 2H).

Provenance & Evidence