Reaction Steps
N1-BOC-(1S,3R)-3-(2H-indazol-1-ylmethyl)cyclopentan-1-amine and N1-BOC-(1S,3R)-3-(1H-indazol-2-ylmethyl)cyclopentan-1-amine: The intermediate was synthesized from 1H-indazole (967 mg, 8.18 mmol) and Intermediate 14 (2.0 g, 6.82 mmol) using 60% sodium hydride (180 mg, 7.52 mmol) in DMA (20 ml) as described in Example 26, Step 1, gave an isomeric mixture of products. The two isomers were separated by silica gel column chromatography using 40% ethyl acetate in petroleum ether. The less polar isomer, isolated as a white solid (700 mg) was characterised as N1-BOC-(1S,3R)-3-(1H-indazol-1-ylmethyl)cyclopentan-1-amine; IR (KBr) 3400, 3324, 1660, 1498, 1417, 1306, 1042 cm−1; 1H NMR (CDCl3, 300 MHz) δ 1.14–1.25 (m, 2H), 1.42 (s, 9H), 1.45–1.58 (m, 3H), 1.68–1.77 (m, 2H), 1.93–2.01 (m, 1H), 2.07–2.17 (m, 1H), 2.54–2.65 (m, 1H), 3.91 (brs, 1H), 4.35 (d, J=6.9 Hz, 2H), 4.53 (brs, 1H), 7.11–7.17 (m, 1H), 7.34–7.42 (m, 2H), 7.73 (d, J=8.1 Hz, 1H), 7.98 (s, 1H). The more polar isomer, isolated as a white solid (500 mg) was characterized as N1-BOC-(1S,3R)-3-(2H-indazol-2-ylmethyl)cyclopentan-1-amine; IR (KBr) 3117, 3058, 2943, 2872, 2239, 1660, 1514, 1412, 1306, 1262, 1191, 1157, 1139, 1042 cm−1; 1H NMR (CDCl3, 300 MHz) δ 1.17–1.27 (m, 1H), 1.43 (s, 9H), 1.46–1.55 (m, 2H), 1.72–1.82 (2H), 1.94–2.03 (m, 1H), 2.15–2.24 (m, 1H), 3.94 (brs, 1H), 4.37 (d, J=7.2 Hz, 2H), 4.61(brs, 1H), 7.05–7.11 (m, 1H), 7.26–7.52 (m, 2H), 7.63–7.79 (m, 2H). Step 2: (1S,3R)-3-(1H-indazol-1-ylmethyl)cyclopentan-1-amine trifluoroacetate: Deprotection of N1-BOC-(1S,3R)-3-(1H-indazol-1-ylmethyl)cyclopentan-1-amine (500 mg, 1.58 mmol), the less polar isomer, using TFA (3 ml) in dry dichloromethane (3 ml) as described in Example 1, Step 2 gave 341 mg of the amine as its TFA salt, which was used as such for the coupling reaction. Step 3: Coupling reaction of Step 2 intermediate (341 mg, 1.58 mmol) with Intermediate 17 (137 mg, 0.79 mmol) in the presence of potassium carbonate (219 mg, 1.58 mmol) and NaI (119 mg, 0.79 mmol) in THF (30 ml) as described in Example 1, Step 3 gave 70 mg of the product as a semisolid; IR (neat) 3400, 3324, 2929, 2872, 2239, 1660, 1498, 1464, 1417, 1362, 1314, 1262, 1192, 1161, 1040 cm−1; 1H NMR (CDCl3, 300 MHz) δ 1.15–1.29 (m, 2H), 1.41–2.01 (m, 3H), 2.07–2.33 (m, 5H), 2.58–2.69 (m, 1H), 3.07–3.13 (m, 1H), 3.34 (s, 2H), 3.36–3.58 (m, 2H), 4.36 (d, J=7.5 Hz, 2H), 4.77 (m, 1H), 7.11–7.19 (m, 1H), 7.33–7.45 (m, 2H), 7.72 (d, J=8.1 Hz, 1H), 7.98 (d, J=0.6 Hz, 1H).
