[4-(2-Amino-ethyl)-phenyl]-carbamic acid tert-butyl ester

Synthesis

[4-(2-Amino-ethyl)-phenyl]-carbamic acid tert-butyl ester is synthesised using 4-tert-butoxycarbonylaminophenylacetonitrile as a raw material by chemical reaction. The specific synthesis steps are as follows:
To a solution of (300 gm, 1.29 moles) N-BOC-4-aminophenylacetonitrile in 3000 ml of methanol, 25% aq. ammonia solution (480 ml) and Raney nickel (45 gm) were added at 25 -30°C. Reaction mixture was subjected to hydrogenation at 50-60 PSI for 4 hrs. After completion of reaction, as indicated from TLC, reaction mixture was filtered and washed with (2 X 25 ml) methanol. Filtrate was concentrated under vacuum and resulting residue was treated with (1500 ml) 1M aq. hydrochloric acid at 25-30°C. Reaction mixture was stirred for 15 minutes and filtered to remove insoluble impurities. Filtrate was basified to pH 10-12 with 50% aq. NaOH solution below 25°C. Precipitated 4-(2-aminoethyl)-N-(tert-butoxycarbonyl) phenylamine was filtered and washed with (2 X 100 ml) water. Solid was dried under vacuum at 55- 60°C for 8-10 hrs. Dry weight: 240 gm (79%). 1H NMR (CDC13 and 400 MHz): δ 1.11 (2H, s), 1.51 (9H, s), 2.68 (2H, t), 2.93 (2H, t), 6.72 (1H, s), 7.10 (2H, d), 7.28 (2H, d).