Etonitazene → HCID 178466242, compound

Participants

Reaction Steps

{2-[2-(4-Ethoxy-benzyl)-5-nitro-benzoimidazol-1-yl]-ethyl}-diethyl-amine 7a (108 mg, 0.273 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. Thiophene-3-carboximidothioic acid benzyl ester hydrobromide 9f (182 mg, 0.575 mmol) is added to the flask and the reaction was stirred under Ar at ambient temperature for 108 hours. The solvent was evaporated and the residue partitioned between H2O and ethyl acetate and 3M sodium hydroxide solution added to adjust pH to 10. The mixture was transferred to a separatory funnel and the organic layer collected. The aqueous layer was further extracted with ethyl acetate and the combined organic layers were washed with brine (twice), dried over magnesium sulphate, filtered and concentrated to afford crude. The product was purified using silica gel dry column chromatography eluting with 5% 2M NH3 in methanol/95% dichloromethane then purified using a second silica gel column eluting with 60% methanol/40% dichloromethane to afford a pale yellow solid 16 N-(1-(2-(diethylamino)ethyl)-2-(4-ethoxybenzyl)-1H-benzo[d]imidazol-5-yl)thiophene-3-carboximidamide. Yield: 40 mg (30.8%) 1H NMR (DMSO) δ; 0.83 (t, 6H, J=7.0), 1.30 (t, 3H, J=6.9), 2.38-2.50 (2×m, 6H), 3.97 (q, 2H, J=7.0), 4.10 (t, 2H, J=6.5), 4.22 (s, 2H), 6.12 (br, 2H), 6.73 (d, 1H, J=8.3), 6.86 (d, 2H, J=8.4), 6.97 (d, 1H, J=1.8), 7.19 (d, 2H, J=8.6), 7.34 (d, 1H, J=8.4), 7.53-7.55 (m, 1H), 7.61-7.66 (m, 1H), 8.13 (d, 1H, J=3.0). MS (ESI): 476 (MH+, 25%), 377 (100%).

Provenance & Evidence