Reaktionsschritte
A solution of 13 (280 mg, 0.77 mmol) in HCl-saturated dioxane (10 mL) was stirred at 10° C. for 2 h, then evaporated to dryness under reduced pressure below 30° C. 5-Nitroindole-2-carboxylic acid [S. M. Parmerter, J. Amer. Chem. Soc. 80, 1958, 4621-4625] (167 mg, 0.81 mmol) EDCI.HCl (370 mg, 1.93 mmol) and DMA (3 mL) were then added and the mixture was stirred at 20° C. for 2 h. Addition of dilute KHCO3 precipitated a yellow solid which was collected, washed well with water and recrystallised from THF to give 14b (282 mg, 81%), mp >300° C. 1H NMR [(CD3)2SO] δ 12.56 (s, 1 H, NH), 9.14 (s, 1 H, H-4), 8.74 (d, J=2.2 Hz, 1 H, H-4'), 8.35 (dd, J=7.0, 2.7 Hz, 1 H, H-6), 8.24 (dd, J=6.8, 2.7 Hz, 1 H, H-9), 8.12 (dd, J=9.1, 2.3 Hz, 1 H, H-6'), 7.80-7.72 (m, 2 H, H-7,8), 7.64 (d, J=9.1 Hz, 1 H, H-7'), 758 (s, 1 H, H-3'), 4.96 (t, J=10.1 Hz, 1 H, H-2), 4.71 (dd, J=10.8, 2.3 Hz, 1 H, H-2), 4.68-4.61 (m, 1 H, H-1), 4.18-4.09 (m, 2 H, CH2Cl).
