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