反応手順
179 a) A suspension of 1-(3-nitro-phenyl)-piperazine hydrochloride (1.0 g, 4.1 mmol) and potassium carbonate (0.62 g, 4.5 mmol) in acetonitrile (10 mL) at room temperature was added di-tert-butyldicarbonate (1.0 g, 4.6 mmol) and was stirred at room temperature for 3 days. The mixture was poured into water (50 mL) and extracted with dichloromethane (3×50 mL). The combined organic layers were washed with water (50 mL) and saturated aqueous sodium chloride (50 mL). The organic layer was dried over magnesium sulfate, filtered and evaporated under reduced pressure. 4-(3-Nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester was isolated as a yellow solid (1.169 g, 93%). 1H NMR (400 MHz, CDCl3, δ, ppm): 7.72 (s, 1H), 7.69 (d, J=8.0 Hz, 1H), 7.39 (t, J=8.2 Hz, 1H), 7.19 (dd, J=8.2, 1.7 Hz, 1H), 3.63-3.58 (m, 4H), 3.27-3.21 (m, 4H), 1.49 (s, 9H). MS=330 (M+Na)+. 179 b) (3-Amino-phenyl)-piperazine-1-carboxylic acid tert-butyl ester was prepared from 4-(3-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (1.17 g, 3.81 mmol) in a manner analogous to Example 111a. Product isolated as a yellow solid (0.993 g, 94%). 1H NMR (400 MHz, CDCl3, δ, ppm): 7.05 (t, J=7.7 Hz, 1H), 6.35 (d, J=8.8 Hz, 1H), 6.26-6.22 (m, 2H), 3.61 (br s, 2H), 3.57-3.53 (m, 4H), 3.12-3.07 (m, 4H), 1.48 (s, 9H). MS=278 (MH)+. 179 c) 4-{3-[8-(4-Methanesulfonyl-phenyl)-[1,2,4]triazolo[1,5-a]pyridin-2-ylamino]-phenyl}-piperazine-1-carboxylic acid tert-butyl ester was prepared from 2-chloro-8-(4-methanesulfonyl-phenyl)-[1,2,4]triazolo[1,5-a]pyridine (500.0 mg, 1.625 mmol) and 4-(3-Amino-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (500.0 mg, 1.803 mmol) with 2,2′-bis-dicyclohexylphosphanyl-biphenyl (90.0 mg, 0.165 mmol) as the ligand in a manner analogous to Example 2d. Product isolated as a yellow foam (0.70 g, 79%). 1H NMR (400 MHz, CDCl3, δ, ppm): 8.51 (d, J=6.6 Hz, 1H), 8.24 (d, J=8.3 Hz, 2H), 8.08 (d, J=8.4 Hz, 2H), 7.66 (d, J=7.4 Hz, 1H), 7.32 (s, 1H), 7.24 (t, J=8.1 Hz, 1H), 7.05-6.99 (m, 2H), 6.89 (s, 1H), 6.59 (d, J=8.2 Hz, 1H), 3.63-3.58 (m, 4H), 3.22-3.17 (m, 4H), 3.10 (s, 3H), 1.50 (s, 9H). MS=549 (MH)+.
