5-Бром-7-азаиндол

White to light brown powder or crystal

In the 250 ml flask is sequentially added in 50 ml ethanol and 5-bromo-1-hydrogen pyrrolo [2,3 - the b] pyridine -2 - ketone (4.2g, 20 mmol), Sn powder (4.7 g, 40 mmol) and 5 mol/L hydrochloric acid (14 ml), 40 ℃ stirring for 2 hours, the reaction is completed, to remove the ethanol, add 50 ml of water residue is completely dissolved, saturated NaHCO3 solution and to pH=8, and filtering the resulting solid, after drying, dissolved in 50 ml chloroform, adding CuBr2(13.4 g, 60mmol), 60 Cstirring for 2 hours, the reaction is completed, the end of the reaction, rotary evaporated to remove chloroform, adding 50 ml saturated NaHCO3 solution, ethyl acetate (3 × 100 ml), the combined organic phase with water (50 ml) for washing and then the saturated salt water (50 ml) washing, anhydrous Na2SO4 drying, filtering, the filtrate is concentrated to obtain 5-bromo-1H-pyrrolo [2,3 - the b] pyridine the crude product, the crude product is chloroform: hexane=2:1 (volume ratio) mixed solution recrystallize to get 3.1 g of pale yellow 5-Bromo-7-azaindole pure product, yield 77.6%, melting point:176.8-177.3 ℃.

The solubility of 5-Bromo-7-azaindole in pure solvents increases with increasing temperature. Among them 5-Bromo-7-azaindole showed the best solubility in methyl acetate and the worst solubility in hexane. The maximum change in solubility of 5-Bromo-7-azaindole in DCM was observed at T = 298.15-313.15 K. The solubility of 5-Bromo-7-azaindole in DCM was found to be the most variable.