[CH:1]1([N:6]2[C:14]3[C:9](=[CH:10][CH:11]=[C:12](C(O)=O)[CH:13]=3)[C:8]([CH2:18][CH3:19])=[N:7]2)[CH2:5][CH2:4][CH2:3][CH2:2]1.C([N:22](CC)CC)C.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=O)C=CC=CC=1>C(O)(C)(C)C>[NH2:22][C:12]1[CH:13]=[C:14]2[C:9]([C:8]([CH2:18][CH3:19])=[N:7][N:6]2[CH:1]2[CH2:5][CH2:4][CH2:3][CH2:2]2)=[CH:10][CH:11]=1To a mixture of 1-cyclopentyl-3-ethyl-1H-indazole-6-carboxylic acid (258 mg) and triethylamine (0.56 mL) in t-butanol (1 ml) was added diphenylphosphoryl azide (0.33 μL). The mixture was stirred at 100° C. for 4 h, then partitioned between water (25 mL) and ether (25 mL). The ether layer was collected, dried (MgSO4), and passed through a plug of silica. The silica was washed with an additional 25 mL of ether and the mixture was concentrated in vacuo. The residue was dissolved in THF (5 mL) and 6N aq. HCL (1 mL) was added and the mixture was stirred for 18 h. Ether (25 mL) and water (25 mL) were added and the ether layer was collected, dried (MgSO4), and concentrated in vacuo. The residue was purified by column chromatography on silica gel to yield 0.14 g of 6-amino-1-cyclopentyl-3-ethyl-1H-indazole (59% yield). 1H NMR (300 MHz) δ 7.45 (d,J=8.4 Hz, 1H), 6.52 (m,2H), 4.74 (p,J=7.8 Hz, 1H), 3.86 (br,2H), 2.95 (q,J=7.7 Hz,2H), 2.3–1.8 (m,6H), 1.8–1.6 (m,2H), 1.37 (t,J=7.7 Hz,3H).
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