180081-10-1

180081-09-8

7440-44-0

180081-10-1

Tert-butyl 2-methyl-2-(4-nitrophenyl)propylcarbamate (725 mg, 2.5 mmol) and ammonium formate (700 mg, 10.9 mmol) were added to 5% wt of palladium carbon (400 mg) in ethanol (25 mL). The mixture was refluxed for 1 h, cooled and filtered through diatomaceous earth. The filtrate was concentrated to afford tert-butyl 2-methyl-2-(4-aminophenyl)propylcarbamate (G-3) (550 mg, 83% yield), and the product could be used in subsequent reactions without further purification. The product was characterized as follows: 1H NMR (400 MHz, DMSO-d6) δ 6.99 (d, J = 8.5 Hz, 2H), 6.49 (d, J = 8.6 Hz, 2H), 4.85 (s, 2H), 3.01 (d, J = 6.3 Hz, 2H), 1.36 (s, 9H), 1.12 (s, 6H); HPLC retention time 2.02 min (gradient: 10-99% CH3CN, run 5 min); ESI-MS m/z 265.2 (MH+).