Hydrazine hydrate (1:1) → 4-(2-(Dimethylamino)ethyl)-3,4-dihydro-2H-benzo[b][1,4]thiazin-7-amine

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To a solution of N,N-dimethyl-2-(7-nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethanamine (0.9695 g, 3.63 mmol) in MeOH (20 mL) was added Raney-Nickel (slurry in water; ˜0.1 g, 3.63 mmol) followed by hydrazine hydrate (1.82 mL, 37.4 mmol). The mixture was immersed in a preheated oil bath and refluxed for 20 minutes. The solution was cooled to room temperature and filtered through a pad of Celite. The filter pad was washed with MeOH, and the crude material was concentrated. The crude material was filtered through a plug of silica gel (2.5:97.5 (2M NH3 in MeOH):CH2Cl2). The collected fractions gave brown viscous oil (0.84 g, 99%). 1H NMR (CDCl3) δ 6.58 (d, J=8.7 Hz, 1H), 6.45 (d, J=2.7 Hz, 1H), 6.40 (dd, J=2.7, 8.7 Hz, 1H), 3.51-3.48 (m, 2H), 3.30 (t, J=7.2 Hz, 2H), 3.03-3.00 (m, 2H), 2.48 (t, J=7.5 Hz, 2H), 2.27 (s, 6H); ESI-MS (m/z, %): 240, 238 (MH+, 100).

Provenance & Evidence