Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: double_bond on November 12, 2008, 01:25:50 PM
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I need to prepare chalcone from vanillin and acetophenone by Claisen - Schmidt condesation .I did the reaction by taking an equimolar quantity of vanilin and acetophenone in 30 ml of ethanol and added 15 ml of 40 % KOH solution and stirred at room temp for 8 hrs and then I poured the reaction mixture into 250 ml of ice cold water and acidified with dil HCl, but I didn't get any product .can any one suggest a method or any modification in this procedure.expecting your valuable suggestions.see the attached image . :)Thank you
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Without doing the math myself, how many equivalents of base did you add?
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How do you know you didn;t get any product? Just because you didn't get a crystalline mass? Do you perhaps get an oil coming out which you should extract into an organic solvent (EtOAc) then analyse by TLC against a standard?
R.
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Is it possible you're getting different products (a aldol between two acetophenone)? I was thinking, what if you modified the procedure such that you dripped acetophenone into the vanillin solution that was in base. This way you minimize the chance of side reaction...
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How do you know you didn;t get any product? Just because you didn't get a crystalline mass? Do you perhaps get an oil coming out which you should extract into an organic solvent (EtOAc) then analyse by TLC against a standard?
R.
yea. I got an oily solution.so let me extract it using (EtOAc).THANK YOU Russellm
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Is it possible you're getting different products (a aldol between two acetophenone)? I was thinking, what if you modified the procedure such that you dripped acetophenone into the vanillin solution that was in base. This way you minimize the chance of side reaction...
That looks interesting let me check .Thank you Macmann .
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when working with small scale generally i do not get reasonable solid in hand and mostly purify by column chromatography. it comes as liquid / gum later on it solidifies slowly, this is my general observations with chalcones.