problem in chalcone synthesis.pdf

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Ram ón J Esté vez ALL ANSWERS (13) Milagro s Avenda ño Braj esh Kum ar Ram ón J Esté vez POPULAR ANSWERS Ramón J Estévez · University of Santiago de Compostela I don't kow your reaction conditions. In my opinion basic conditions are not a good choice, because the phenolic groups are probably converted into the corresponding phenoxy groups and this could dramatically reduce the basic character of the protons in alfa position to the cabonyl group. We have prepared some chalcone related compounds using ammonium acetate/acetic acid mixtures. Try to use the following proportions: chalcone (0.66 mmol), aldehyde (0.66 mmol), NH4OAc (1.46 mmol) and AcOH (6 mL). May 27, 2013 Milagros Avendaño · Central University of Venezuela Hi, I noticed that you do not specify the reactive agents you are using. If you are working in a basic medium take in account that your acetophenone reactant has two phenol groups which are acidic. Maybe that is what’s troubling you May 27, 2013 Brajesh Kumar · Escuela Politécnica del Ejército You are using 2, 4 dihydroxy acetophenone and other benzaldehyde in basic condition (NaOH in Methanol), Try to reduce the volume after preperation of Chalcone and keep in refrigerator for overnight, Chalcone must precipitate. Becoz, dihydroxy chalcone are highly soluble in methanol/ water mixture. May 27, 2013 Ramón J Estévez · University of Santiago de Compostela I don't kow your reaction conditions. In my opinion basic conditions are not a good choice, because the phenolic groups are probably converted into the corresponding phenoxy groups and this could dramatically reduce the basic character of the protons in alfa position to the cabonyl group. We have prepared some chalcone related compounds using ammonium Umangkumar Harishchandra Shah Charotar University of Science and Technology 2 / 1 Problem in chalcone synthesis. In a part of my research, I am synthesizing a chalcone from 24dihydroxy acetophenone and various benzaldehyde derivatives. I am following your procedure published in article but I could not get the success in the reactions so please help me. TOPICS May 27, 2013 Chalcones Share 1s2.0S0040403902009905main1.pdf More questions, even more answers Over 200 000 questions asked Over 1 million answers provided 75% of questions answered within 48 hours Join for free QUESTION FOLLOWERS (22) See all Views 2655 Followers 22 Answers 13 JOIN FOR FREE LOG IN Got a question you need answered quickly? Technical questions like the one you've just found usually get answered within 48 hours on ResearchGate. Sign up today to join our community of over 7 million scientific professionals. Join for free

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Page 1: Problem in chalcone synthesis.pdf

6/25/2015 Problem in chalcone synthesis.  ResearchGate

http://www.researchgate.net/post/Problem_in_chalcone_synthesis2 1/3

Ramón JEstévez

ALL ANSWERS  (13)

MilagrosAvendaño

BrajeshKumar

Ramón JEstévez

POPULAR ANSWERS

Ramón J Estévez · University of Santiago de Compostela

I don't kow your reaction conditions. In my opinion basic conditions arenot a good choice, because the phenolic groups are probably convertedinto the corresponding phenoxy groups and this could dramaticallyreduce the basic character of the protons in alfa position to the cabonylgroup.We have prepared some chalcone related compounds using ammoniumacetate/acetic acid mixtures. Try to use the following proportions:chalcone (0.66 mmol), aldehyde (0.66 mmol), NH4OAc (1.46 mmol) andAcOH (6 mL).

 May 27, 2013

Milagros Avendaño · Central University of Venezuela

Hi, I noticed that you do not specify the reactive agents you are using. Ifyou are working in a basic medium take in account that youracetophenone reactant has two phenol groups which are acidic. Maybethat is what’s troubling you

 May 27, 2013

Brajesh Kumar · Escuela Politécnica del Ejército

You are using 2, 4 dihydroxy acetophenone and other benzaldehyde inbasic condition (NaOH in Methanol), Try to reduce the volume afterpreperation of Chalcone and keep in refrigerator for overnight, Chalconemust precipitate. Becoz, dihydroxy chalcone are highly soluble inmethanol/ water mixture.

 May 27, 2013

Ramón J Estévez · University of Santiago de Compostela

I don't kow your reaction conditions. In my opinion basic conditions arenot a good choice, because the phenolic groups are probably convertedinto the corresponding phenoxy groups and this could dramaticallyreduce the basic character of the protons in alfa position to the cabonylgroup.We have prepared some chalcone related compounds using ammonium

Umangkumar Harishchandra ShahCharotar University of Science and Technology

2   / 1 

Problem in chalcone synthesis.

In a part of my research, I am synthesizing a chalcone from 24dihydroxyacetophenone and various benzaldehyde derivatives. I am following yourprocedure published in article but I could not get the success in the reactions soplease help me.

TOPICS

May 27, 2013

Chalcones

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Page 2: Problem in chalcone synthesis.pdf

6/25/2015 Problem in chalcone synthesis.  ResearchGate

http://www.researchgate.net/post/Problem_in_chalcone_synthesis2 2/3

JamesSherwood

Sameralihasan

Sameralihasan

acetate/acetic acid mixtures. Try to use the following proportions:chalcone (0.66 mmol), aldehyde (0.66 mmol), NH4OAc (1.46 mmol) andAcOH (6 mL).

 May 27, 2013

James Sherwood · The University of York

Acid catalysis is the way to go! Any strong acid should work (12 mol%).No solvent is needed if you're using at least one liquid reactant, stirringat 100120 C, no special atmosphere are drying required. Cool down forprecipitation of the product.

 May 28, 2013

Krishnasarma pathy/ SARMA KRISHNA PATHY · IPL LTD

Providing various methods of experimental process followed forpreparing chalcone Solution phase conventional method:A mixture of 2, 4dihydroxy acetophenone (0.01 mol) and aryl aldehydes(0.01 mol) wasstirred in ethanol (30 mL) and then an aqueous solution of KOH (40%,15 mL) was added to it. The reaction mixture was kept overnight at roomtemperature and then it was poured in to crushed ice and acidified withHCl. The solid separated was filtered and recrystallizedfrom ethanol Solid phase microwave method:To a solution of 2, 4dihydroxyacetophenone (0.01 mol) and substitutedaromatic aldehyde(0.01mol) in DMF (5mL) taken in 100 mL borosil flask,was added montmorrilonite K 10clay (4g). The mixture was uniformlymixed with glass rod and air dried to remove thesolvent. Adsorbedmaterial was irradiated inside a microwave oven for specified timemedium power level (600 W). After the completion of the reaction(monitored by TLC), the reaction mixture was cooled at roomtemperature and the product was extracted with ethanol (2 x 20 mL).Removal of the solvent and subsequent recrystallisation with ethanol

 May 28, 2013

Hassan Faidallah · King Abdulaziz University

you may need to acidify with 20% HCl after pouring in water since youhave to acidic OH

 May 28, 2013

Dr. Amit Tapas · Sudhakarrao Naik Institute of Pharmacy

First try to protect the hydroxyl group with DMS or Benzoyl Chloride orother protecting group (information you will get from literature). Thencarry out the reaction of protected dihydroxyacetophenone with suitablearomatic aldehyde. Protection is must since phenolic hydroxyl group aremuch reactive.

 Jun 7, 2013

Samer ali hasan · University Of Kufa

Using thionyl chloride in ethanol as a catalyst will avoid any problems inthe chalcone synthesis as hydroxyl group which not need to protection

 Aug 14, 2013

Samer ali hasan · University Of Kufa

follow my procedure in my article and you will get your target

SYNTHESIS OF NEW FLUORINATED CHALCONE DERIVATIVE WITHANTIINFLAMMATORY ACTIVITY

 Aug 14, 2013

1s2.0S0040403902009905main1.pdf

Page 3: Problem in chalcone synthesis.pdf

6/25/2015 Problem in chalcone synthesis.  ResearchGate

http://www.researchgate.net/post/Problem_in_chalcone_synthesis2 3/3

HassanFawzyMadkour

Fathi Aqra · Hebron University

See this article:Rajender S. Varma, Manju Varma,Monatshefte für Chemie / Chemical MonthlyDecember 1982, Volume 113, Issue 12, pp 14691473

 Dec 27, 2013

Madhukar Baburao Deshmukh · Shivaji University, Kolhapur

React 2,4dihydroxy acetophenone with benzaldehyde in presence ofNaoH stirr the reaction mix. with cooling, the chalcone separates out .

 May 31, 2014

Hassan Fawzy Madkour · Ain Shams University

Please kindly read the following article to find the solution of yourproblem:

Analele Universităţii din Bucuresti – Chimie (serie nouă), vol 20 no. 1,pag. 15 – 24

K.L. Ameta , Nitu S. Rathore and Biresh Kumar

Good luck.

 Mar 27, 2015

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