1-METHYL-1H-INDOLE-4-CARBOXYLICACID

Oxalyl chloride (1.55 mL, 18.3 mmol) was added to a suspensionof the above acid (2.48 g, 15.3 mmol) in DCM (100 mL, anhydrous)and DMF (0.05 mL, 0.64 mmol) at 20 C. The mixture wasstirred at 20 C for 1 h to give a colourless solution which wascooled to 0 C. N, O-Dimethylhydroxylamine hydrochloride (1.64g, 16.8 mmol) and pyridine (3.71 mL, 45.9 mmol) were addedsequentially and the mixture was stirred at 20 C for 18 h, thenpartitioned between EtOAc and sat. aq. NaHCO3. Column chromatographywith 95:5 DCM:EtOAc gave N-methoxy-N-methylbenzofuran-5-carboxamide (2.28 g, 73%) as a pale brown oil. 1H NMR(CDCl3) d 7.99 (d, J = 1.4 Hz, 1H), 7.65-7.69 (m, 2H), 7.52 (dt, J =8.6, 0.6 Hz, 1H), 6.82 (dd, J = 2.2, 0.9 Hz, 1H), 3.56 (s, 3H), 3.39 (s, 3H). Found: [M+H] = 206.2.[82] Into a 40-mL vial, was placed a solution of 1 -methyl- lH-indole-4-carboxylic acid (100 mg, 0.57 mmol, 1.00 eq.) in N, N-dimethylformamide (6 mL), HATU (325 mg, 0.86 mmol, 1.50 eq.), and DIEA (368 mg, 2.85 mmol, 5.00 eq.). After stirring for 1 h at 25 C, 4, 5, 6, 7-tetrahydro-2H-indazol-3-amine hydrochloride (119.7 mg, 0.57 mmol, 1.00 eq.) was added. The resulting solution was stirred for 18 h at 25 C. The reaction mixture was diluted with water (40 mL), extracted with ethyl acetate (40 mL x3), washed with brine (100 mL x2), dried over anhydrous sodium sulfate, filtered and concentrated under vacuum. The crude product was purified by Prep-HPLC with the following conditions: Column, XBridge Shield RP18 OBD Column, 5 um, 19x150 mm; mobile phase, water (0.1 %FA) and ACN (30.0% ACN up to 55.0% in 12 min); Detector, UV 254 nm to give two isomers. [83] Fraction A (Example 7): Rt=10.40 min; Yield: 15.4 mg (9%) as a light yellow solid. (ES, m/z) [M+H]+ : 295; iNMR (DMSO- 6, 400MHz, ppm): delta 7.65 (d, J= 8.0 Hz, 1H), 7.61-7.59 (m, 1H), 7.44 (d, J=2.8 Hz, 1H), 7.24-7.21 (m, lH), 6.49-6.48 (m, 1H), 6.40 (s, 2H), 3.84 (s, 3H), 2.36-2.30 (m, 4H), 1.69-1.66 (m, 4H).[84] Fraction B ( Example 8 ): Rt= 8.35 min; Yield: 21.2 mg (13%) as a white solid. (ES, m/z) [M+H]+ : 295; 1HNMR (DMSO- 6, 400MHz, ppm): delta 7.60 (d, J= 8.0 Hz, 1H), 7.49-7.47 (m, 1H), 7.39 (d, J=2.8 Hz, 1H), 7.21-7.18 (m, lH); 6.42-6.41 (m, 1H), 5.35 (s, 2H); 3.83-3.81 (m, 3H), 2.96-2.94 (m, 2H), 2.28-2.26 (m, 2H), 1.74-1.69 (m, 4H).