Sodium Bicarbonate → 1H-Indazole

Participants

Reaction Conditions

Reaction Steps

E-2-Bromostyrene (23 μL, 0.174 mmol, 2.5 equiv) was dissolved in THF (1.0 mL) and was cooled to −78° C. t-BuLi (205 μL, 0.348 mmol, 5.00 equiv) was added and the mixture was warmed to 42° C. for 7 min to give a deep red mixture. The solution was added to freshly dried zinc chloride (29 mg, 0.209 mmol, 3.00 equiv) via cannula and the mix was allowed to warm to 23° C. with stirring for 20 min. This solution was added to a neat mixture of 3-Iodo-6-(1-phenyl-vinyl)-1-[2-(trimethyl-silanyl)-ethoxymethyl]-1H-indazole (33.1 mg, 0.0696 mmol, 1.0 equiv) and Pd(PPh3)4 (4 mg, 0.0035 mmol, 0.05 equiv) at 23° C. via cannula. This solution was allowed to stir for 15 min and was treated with saturated sodium bicarbonate and extracted with ethyl acetate. The organic material was dried over sodium sulfate, decanted and concentrated. Purification by silica gel chromatography using two columns (5:95 ethyl acetate-hexane; 12 mL silica: and 1:99 ethyl acetate-benzene; 12 mL silica) gave 6-(1-Phenyl-vinyl)-3-styryl-1-[2-trimethyl-silanyl)-ethoxymethyl]-1H-indazole (16.2 mg, 51%): Rf sm 0.38, p 0.29 (ethyl acetate-hexane 1:9); 1H NMR (300 MHz, CDCl3) δ 7.98 (d, 1H, J=8.4 Hz), 7.62-7.22 (m, 14H), 5.71 (s, 2H), 5.57 (s, 2H), 3.60 (t, 2H, J=8.2 Hz), 0.90 (t, 2H, J=8.2 Hz), −0.08 (s, 9H); HRMS (FAB) [m+H]/z Calc'd 453.2362, Found 453.2354.

Provenance & Evidence