Sodium Carbonate → 6-phenyl-3-styryl-1-[2-(trimethyl-silanyl)ethoxymethyl]-1H-indazole

Participants

Reaction Conditions

Reaction Steps

6-phenyl-3-styryl-11[2-(trimethyl-silanyl-ethoxymethyl]-1H-indazole (345 mg, 0.81 mmol) was treated with a solution of TBAF (16 ml of a 1 M solution in THF, 16 mmol), and ethylene diamine (0.53 ml, 8.1 mmol), and heated at 70° C. for 2 h. The solution was then poured into brine (200 ml), and extracted with ethyl acetate (3×30 ml). The organic layer was dried over MgSO4, and concentrated under reduced pressure. Purification by silica gel chromatography gave 6-phenyl-3-E-styryl-1H-indazole as a white solid (80 mg, 34%): 1H N (300 MHz, CDCl3) δ 8.10 (d, 1H, J=8.5 Hz); HRMS (FAB) [M+H]/z Calc'd 297.1392, found 297.1393. Anal. Calc'd, C (85.10), H (5.44), N (9.45). Found: C (85.10), H (5.46), N (9.43). The starting material was prepared as follows: A solution of 476 mg (1.0 mmol) of 6-iodo-3-styryl-1-[2-(trimethyl-silanyl)ethoxymethyl]-1H— indazole, from Example 14 step (i), in dioxane (3 ml, degassed by sonication and bubbling argon), Pd(PPh3)4 (23 mg, 0.05 mmol), phenylboronic acid (302 mg, 2.5 mmol), and Na2CO3 (1.25 ml of a 2M aqueous solution, degassed as above) was heated at 90° C. for 2 h. The solution was then diluted with ethyl acetate (100 ml) and washed with brine (2×20 ml). The organic layer was dried over MgSO4, and concentrated under reduced pressure. Purification by silica gel chromatography gave of 6-phenyl-3-styryl-1-[2-(trimethyl-silanyl)ethoxymethyl]-1H— indazole as a brown oil (345 mg, 81%). 1H NMR (300 MHz, CDCl3) δ 8.09 (dd, 1H, J=8.5, 0.7 Hz), 7.75 (s, 1H), 7.70 (d, 1H, J=7.0 Hz), 7.647.58 (m. 2H), 7.56-7.51 (m, 2H), 7.50-7.45 (m, 2H), 7.45-7.36 (m, 4H), 7.34-7.27 (m, 1H), 5.80 (s, 2H), 3.73 (t, 2H, J=8.3 Hz), 1.12 (t, 2H, J=8.3 Hz).

Provenance & Evidence