Ammonium Chloride → 2-Ethoxy-5-(4-ethyl-1-piperazinylsulfonyl)benzamidine

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Reaction Steps

Trimethylaluminium (10 mL, 2 Molar solution in hexanes) was added dropwise to a slurry of ammonium chloride (1.07 g, 0.02 Mol) in toluene (15 mL) at 0° C. The mixture was stirred without cooling until gas evolution stopped. 2-ethoxy-5-(4-ethyl-1-piperazinylsulfonyl)benzonitrile (the compound of Preparation 7) (3.23 g, 0.01 Mol) was then added and was washed in with toluene (5 mL) before the reaction was stirred at 80° C. for 40 h. After cooling to room temperature silica gel (15 g) and dichloromethane (100 mL) were added. The mixture was then filtered and the solids were washed with dichloromethane/methanol mixtures. The combined filtrate and washings were evaporated and the residue was chromatographed over silica gel using dichloromethane methanol mixtures to afford 1.08 g, 28.6% of the title compound. M/Z=found 341 (M+H). 1H NMR (CD3OD) 1.28 (t, 3H) 1.49 (t, 3H) 2.97 (q, 2H) 3.14 (br, s, 4H) 3.33 (br, s, 4H) 4.32 (q, 2H) 7.45 (d, 1H) 7.96 (d, 1H) 8.05 (dd, 1H).

Provenance & Evidence