Hydrochloric Acid → 2,3-Dihydro-1H-isoindol-5-amine

Participants

Reaction Steps

Part B. To a solution of the isoindoline (5.40 g, 21.3 mmol) made above in EtOH (266 mL) under N2 was added 20% Pd(OH)2/C (3.00 g, 4.25 mmol). The reaction mixture was hydrogenated at 45 psi for 1 h. TLC analysis indicated that the nitro functionality was reduced and the Bn group was still intact. Therefore, concentrated HCl (1.6 mL, 19.1 mmol) was added to the reaction mixture and hydrogenation (50 psi) was continued overnight. The mixture was filtered through Celite®, washed with MeOH, and the filtrate was concentrated to one fourth of the volume. The precipitate was filtered off to provide the 5-aminoisoindoline.HCl (1.32 g, 36% yield): 1H NMR (500 MHz, CDCl3) δ 9.88 (s, br, 2H), 7.00 (d, 1H), 6.54 (m, 2H), 5.44 (s, br, 2H), 4.32 (s, 2H), 4.28 (s, 2H); ESI MS m/z 135 (M−HCl+H)+.

Provenance & Evidence