Hydrazine hydrate (1:1) → tert-Butyl 2-(7-amino-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethyl(methyl)carbamate

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Reaction Steps

To a solution of tert-butyl methyl(2-(7-nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethyl)carbamate (0.8811 g, 2.493 mmol) in MeOH (20 mL) was added Raney-Nickel (slurry in water; 0.5 g, 2.493 mmol) followed by hydrazine hydrate (1.213 mL, 24.93 mmol). The mixture was then immersed in a preheated oil bath and refluxed for 5 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 then filtered through a silica plug (70% EtOAc/hexanes). The collected fractions were concentrated to give brown oil (0.78 g, 98%). 1H NMR (CDCl3) δ 6.64-6.58 (m, 1H), 6.45 (d, J=2.4 Hz, 1H), 6.39 (d, J=8.4 Hz, 1H), 3.53-3.50 (m, 2H), 3.39-3.28 (m, 4H), 3.01-2.98 (m, 2H), 2.90 (s, 3H), 1.45 (s, 9H); ESI-MS (m/z, %): 326, 324 (MH+, 95), 268 (100).

Provenance & Evidence