The procedure:
2,5-dibromonitrobenzene (16.86 g, 60 mmol) and potassium carbonate anhydrous (82.93 g, 600 mmol) were added in 89.89 mL of dry dimethyl sulfoxide (DMSO) under the nitrogen atmosphere. The reaction mixture was then heated up to 50oC. Another set of solution mixture was prepared by placing diethyl malonate (48.05 g; 300mmol) into 44.94 mL of DMSO after which this solution mixture was added dropwise to the heated reaction mixture for more than an hour. After that, the reaction was allowed to react for 18 hours. After that, the reaction mixture was extracted three times using diethyl ether. The collected organic phase was washed with distilled water and light yellow oil mixture was obtained. This mixture was found to contained diethyl-2-(4-bromo-2-nitrophenyl) malonate and diethyl malonate. This mixture was then dissolved in another prepared solution mixture that contains water (110 mL), sulfuric acid (110 mL), and ethanol (330 mL) in ratio 1:1:3, after which the mixture was heated under reflux. During reflux, zinc powder (39.24 g, 600mmol) was added slowly into the mixture. After that, the reaction mixture was continued to reflux for an hour after which another batch of zinc powder with the same amount was added slowly. The mixture was left to react for another 2 hours and the product obtained was mixed into 1.5 L of distilled water. The solution product was left overnight for crystallization after which it is filtered and white solid material obtained was washed with distilled water (Grenier et al., 2012).
Questions:
Is the zinc powder remains in the final solution mixture? BEFORE I mix the product into 1.5L of water, there are some dark powder (seems to be like the zinc) and together with white solid powder. Is the white solid powder my final product? or it is zinc hydroxide?
After crystallized for one night, the crystal solid is floaded but not settle down and the color of solid is reddish yellow even after washed with distilled water.
Which one supposed to be the product? the white solid powder before crystallized or the reddish yellow solid?
I am trying to synthesize 6-bromo-oxindole
Characterize using NMR spectra. Moat probably redddish yellow coloured compound is your required one.
Check your compound solubility. Add activated carbon to the clear solution and under hot condition filter through hyflow bed.
All of your inorganics adsorbed!!
Best of luck
Not at all. Infact it will improve the description of your compound followed by removal of heavy metal content and if any other inorganics.
Please proceed., as I mentioned earlier.
Good luck and doubts please drop me again
Simply dissolving in an organic solvent like dichloromethane or chloroform, and filtering through Celite, or a similar filter aid, will remove zinc and zinc salts. Charcoal is best suited for water and alcoholic solutions
Reflux 6 bromo isatine with hydrazine and triethyl amine at 120 C for 8 hrs. Cool to rt add HCl to make PH 2 stirred it for 1hr.. Then add saturated NaoH to make pH 7 ..You will get 6 bromo oxindole..
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