Etonitazene → N-(1-(2-(diethylamino)ethyl)-2-(4-ethoxybenzyl)-1H-benzo[d]-imidazol-5-ylcarbamothioyl)benzamide

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Reaction Steps

{2-[2-(4-Ethoxy-benzyl)-5-nitro-benzoimidazol-1-yl]-ethyl}-diethyl-amine 7a (377 mg, 0.950 mmol) was reduced to the amine 8a as outlined above and the resulting ethanolic solution charged to a small, argon purged flask fitted with a magnetic stirbar. Anhydrous tetrahydrofuran (10 mL) added followed by dropwise addition of benzoyl isothiocyanate (178 mg, 1.093 mmol) and mixture stirred under Ar at ambient temperature for 3 hours then allowed to stand overnight at room temperature. 3-(Dimethylamino)propyl functionalized silica gel (205 mg, 0.286 mmol) added and mixture stirred for 1 hour, filtered and concentrated to yield crude. The product was purified using silica gel column chromatography eluting with 2.5% 2M NH3 in methanol/97.5% dichloromethane to afford a pale yellow oil. Trituration with diethyl ether/hexanes yielded an off white solid 20 N-(1-(2-(diethylamino)ethyl)-2-(4-ethoxybenzyl)-1H-benzo[d]-imidazol-5-ylcarbamothioyl)benzamide. Yield: 160 mg (31.7%) 1H NMR (DMSO) δ: 0.80 (t, 6H, J=7.0), 1.30 (t, 3H, J=7.0), 2.34-2.50 (2×m, 6H), 3.98 (q, 2H, J=7.0), 4.16 (t, 2H, J=6.3), 4.27 (s, 2H), 6.87 (d, 2H, J=8.4), 7.18 (d, 2H, J=8.5), 7.34 (d, 1H, J=8.4), 7.44-7.59 (2×m, 3H), 7.62-7.69 (m, 1H), 7.94-8.03 (2×m, 3H), 11.48 (br s, 1H), 12.60 (br s, 1H). MS (ESI): 530 (MH+, 100%)

Provenance & Evidence