Hydrochloric Acid → Hydrochloric Acid

Participants

Reaction Steps

Nitro compound 14 (0.48 g, 1.18 mmol) was suspended in 2:1 EtOH:H2O (100 mL) and the resulting suspension brought to reflux. To this mixture was sequentially added Fe dust (0.30 g, 9.59 mmol) and c.HCl (2 mL), and the resulting suspension refluxed for 15 min. TLC and LCMS analysis at this time showed that the reaction was incomplete, thus further quantities of Fe dust (0.80 g, 14.29 mmol) and c.HCl (10 mL) were added, and the mixture refluxed for a further 50 min. After this time, the reaction was complete, and thus the reaction mixture was filtered hot through a pad of Celite, and solvent was removed under reduced pressure. The residue was dried via two MeOH-azeotrope cycles, and then re-dissolved in MeOH and stirred overnight with Celite and activated charcoal. The resulting slurry was filtered through a pad of Celite, and solvent was removed under reduced pressure. The residue was re-dissolved in MeOH and adsorbed onto a quantity of silica gel, and the resulting silica adsorbate was purified by column chromatography on silica gel, eluting with 1%→20% MeOH:CH2Cl2 (with 0.5% aq.NH3), to afford crude 15. This material was purified further by re-precipitation from MeOH:methanolic HCl:EtOAc, to afford amine 15 as an amorphous cream solid (15 mg, 3%—presumably much material lost by adsorption to activated charcoal,; latter was extracted several times, to little avail); 1H NMR [(CD3)2SO]: δ 11.40 (v v br s, 1H, quinolinyl-N+—H), 10.08 (s, 1H, ArH), 7.94 (ddd, J=9.40, 4.51, 2.59 Hz, 2H, ArH), 7.78 (d, J=8.67 Hz, 2H, ArH), 7.52 (ddd, J=9.40, 4.49, 2.61 Hz, 2H, ArH), 7.27 (d, J=6.95 Hz, 1H, ArH), 6.71 (d, J=8.52 Hz, 2H, ArH), 5.96 (dd, J=6.96, 1.93 Hz, 1H, ArH) [ArOH & ArNH2 not visible]; LCMS (APCI+): 338 (100%), 423 (60%), 169 (40%).

Provenance & Evidence