Hydrochloric Acid → HCID 55080110, compound

Participants

Reaction Conditions

Reaction Steps

(2,4-Dinitro-phenyl)-(1-methyl-piperidin-4-yl)-amine 51 (1.50 g, 5.352 mmol) was dissolved in anhydrous EtOH (20 mL) in a 2 neck 250 mL argon purged flask. The reaction vessel was fitted with a condenser and dropping funnel and heated in an oil bath to 65° C. H2O (20 mL), EtOH (40 mL) and aqueous (NH4)2S (50 wt %, 2.55 g, 18.73 mmol) were charged to the dropping funnel and added to the hot reaction mixture dropwise over 30 minutes. The reaction was heated at 75° C. for 2 hours then cooled to room temperature overnight. Mixture was acidified by the addition of aqueous 4M HCl to adjust pH to 2. The reaction mixture was filtered to remove any insoluble material and the filtrate was concentrated under reduced pressure to remove EtOH. The resulting aqueous solution was basified by the addition of aqueous 2M ammonium hydroxide solution to adjust pH to 10. The aqueous solution was diluted with dichloromethane and transferred to a separatory funnel and the organic layer collected. The aqueous layer was further extracted with dichloromethane and the combined organic layers were washed with H2O, brine, and dried over magnesium sulphate, filtered and concentrated to afford a dark red oil. The product was purified using silica gel dry column chromatography with a solvent system of 5% 2M NH3 in methanol/95% dichloromethane to afford an orange solid 52 N1-(1-Methyl-piperidin-4-yl)-4-nitro-benzene-1,2-diamine Yield: 0.342 grams (25.5%). 1H NMR (DMSO) δ: 1.42-1.55 (m, 2H), 1.89-1.93 (m, 2H), 1.97-2.05 (m, 2H), 2.17 (s, 3H), 2.70-2.81 (m, 2H), 3.30-3.42 (m, 1H), 5.20 (br s, 2H), 5.63 (br d, 1H, J=7.4), 6.53 (d, 1H, J=9.0), 7.39 (d, 1H, J=2.9), 7.49 (dd, 1H, J=8.9, 2.7); MS (ESI): 251 (MH+, 100%).

Provenance & Evidence