To a stirred, ice-bath cooled mixture of tert-butyl 4-[N-(5-(2-benzyloxy-ethanoylamino)-6-cyanoindan-1-yl)amino]benzoate (3.77 g, 7.59 mmol), EtOH (70 ml), and H2O (11 ml) was added 30% H2O2 (8.05 ml) followed by granulated NaOH pellets (0.640 g, 16.0 mmol). The reaction mixture was stirred at 0° C. for 10 min, then placed in an oil-bath preheated to 55° C. and stirred at this temperature for 1 hour. The solvents were then removed in vacuo; the residue was treated with H2O (80 ml) and the pH was adjusted to ˜5 with 1N HCl. The pale yellow solid was collected by filtration, washed with H2O and dried in vacuo over P2O5 (3.56 g, 95%); mp 194-195° C.; 1H-NMR (250 MHz, DMSO-d6, TMS) 1.52 (s, 9H, C(CH3)3), 1.90 (m), 2.62 (m) (1H each, 7-CH), 2.90-3.17 (m, 2H, 8-CH2), 4.43, 4.60 (2×s, 2H each, PhCH2 and OCH2CO), 5.18 (q, J=7.43 Hz, 1H, 6-CH), 6.79 (d, J=8.8 Hz, 2H, 3′,5′-ArH), 6.87 (d, J=8.0 Hz, 1H, N10—H), 7.34 (m, 5H, PhCH2), 7.54, 7.92 (2×s, 1H each, 5-H and 9-H), 7.68 (d, J=8.9 Hz, 2H, 2′,6′-ArH), 12.20 (s, 1H, CONH); MS (ESI, m/z) 520 {(M+Na)+, 90%,}, 498 {(M+H)+, 100%}; Found: C, 72.13; H, 6.25; N, 8.38; C30H31N3O4 requires C, 72.41; H, 6.28; N, 8.44%.
