4-(2,5-Dioxopyrrolidin-1-yl-oxycarbonylamino)-indazole-1-carboxylic acid methyl ester (3.31 g, 9.96 mmol) was added to a solution of 2-(1-aminoindan-5-yl)-2-methylpropionitrile (2.09 g, 10.5 mmol) and DIPEA (1.8 mL, 10.3 mmol) in DMF (40 mL) under nitrogen atmosphere at ambient temperature. After 1 hour the reaction solution was diluted with water (200 mL), the resulting white precipitate was filtered off, washed with water and air-dried. The wet cake was added to a solution of methanol (100 mL), water (3 mL) and TEA (2.8 mL, 20.1 mmol). The mixture was refluxed for 30 minutes, cooled the solution to room temperature, diluted with water (500 mL), collected the white precipitate by filtration, rinsed with water and air-dried. The wet cake was vacuum dried to constant weight, yielding 1-[5-(cyano-isopropyl)-indan-1-yl]-3-(1H-indazol-4-yl)-urea (3.32 g, 93%) as a white solid. MS (ESI) m/z: 360.07 [M+H]+. 1H NMR (DMSO-d6) δ: 1.69 (s, 6H), 1.87 (m, 1H), 2.47 (m, 1H), 2.89 (m, 1H), 2.98 (m, 1H), 5.19 (q, 1H), 6.73 (d, 1H), 7.08 (d, 1H), 7.22 (t, 1H), 7.39 (s, 2H), 7.44 (s, 1H), 7.66 (d, 1H), 8.04 (s, 1H), 8.59 (s, 1H), 13.00 (s, 1H). Anal Calcd for C21H21N5O.0.4H2O: C, 68.80; H, 5.99; N, 19.10. Found: C, 68.94; H, 5.72; N, 18.95.
