Science topic

Benzoic Acids - Science topic

Acids, salts, and derivatives of BENZOIC ACID.
Questions related to Benzoic Acids
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I want to create an ester by using benzoic acid and benzyl bromide, but not able to decide which catalyst and solvent will be appropriate for this ester formation reaction.
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Acetone + anh. K2CO3 powder
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Respected everyone,
I am trying to attach the amine group of glutamic acid with a meta amino benzoic acid through a amide bond. As the glutamic acid is insoluble in THF or DCM, it is very difficult to do with the help of SOCL2.
If anyone have some solutions regarding the reaction conditions, please help.
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Thank you sir for this information. If possible please share some references or procedure for this. This will be a great help.
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I recently conducted DNA-SIP experiment where substrate was 13C labelled carboxyl group (99%) model compound (e.g. Decanoic acid-1-13C, benzoic acid). The sequencing data indicates that 75% of the reads were Methylotrophs (Methylobacillus). Remaining 25% are Pseudomonas, Sediminibacter, etc. I have previously observed methanogens in similar system so I believe that methane production is likely. However, I am not sure why Methylotrophs would be that much high? I was expecting some other bugs to be high who might be responsible in degradation of these model compounds but it didn't come along. But I am also considering that the Methylobacillus might have been feeding on the products of other compounds? In that case, what degradation pathways one can expect with such high abundance of methylotrophs.
Can you please provide some insights or I am thinking in a wrong direction?
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here is the final story i generated.
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I am synthesizing the 2-amino-5-(4-chloro/bromophenyl)-1,3,4-thiadiazole by the reaction between 4-chloro or 4-bromo benzoic acid and thiosemicarbazide using Phosphorous oxychloride. As per the literature, the reaction needs to be done 4 hrs of refluxing after adding water. But I faced the problem, starting material was still there in the reaction even after the refluxing of 24 hrs. Hence reaction failed. Please suggest to me some appropriate method. Because I have tried these reactions 5 times but I failed to get the product.
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Dear Shivani,
many thanks for your kind response and explanation. Another question which comes to my mind is: How do you know that starting materials were still present in the reactions mixture? Did you not get a precpitate after adding the NaOH solution?
There are two points where you should perhaps modify your experiment. First of all, the protocoll calls for 4 hours of reflux, not 24 hours. In this case I suggest that you strictly follow the published procedure. Yet another important factor which yould lead to failure of the reaction is the purity (or impurity) of your phosphorus oxychloride. POCl3 is fairly easily hydrolyzed. Thus if you perhaps used an older sample of POCl3 it could well be that it was already partially hydrolyzed. I would suggest to run the reaction again using a freshly distilled sample of POCl3 and also limit the time for heating at reflux to 4 hours as described.
Good luck with your experiment and best wishes, Frank Edelmann
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I am having a difficulty in analyzing the 1H-NMR spectrum for benzoic acid(attained from recrystallization). I have no idea where the peak of 4.750ppm came from. I thought it was the salicylic acid since it was the thing that was ridded off during the recrystallization process but after some research, I found out that salicyclic acid has no peak at 4.750ppm so I am quite confused.. please help me out,,, thank you in advance
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Isn't it just water? (Check the chemical shift of trace water in your deuterated solvent)
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I have to synthesize the glycosides of benzoic acid derivatives. Can anybody suggest a detailed procedure with experimental experiences?
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Dear Sachin Wazalwar many thanks for your interesting technical question. In general, glycosides derived from benzoic acid can be synthesized by reaction of carbohydrates with activated forms of benzoic acid such as benzoylchloride or 1-benzoylimidazole. Benzoic acid itself will not react directly with carbohydrates. For the first variant (benzoylchloride) please see this relevant research article entitled
Regio/Site-Selective Benzoylation of Carbohydrates by Catalytic Amounts of FeCl3
This article is freely available as public full text on RG.
The second variant (1-benzoylimidazole) is described in detail in the following article entitled
Regioselective Benzoylation of Diols and Carbohydrates by Catalytic Amounts of Organobase
This paper is Open Access and can bee freely downloaded from the general internet. For your information please see the attached pdf file.
The following paper describes a more exotic benzoylation reaction of carbohydrates. This method uses benzoic acid in the presence of sucrose phosphorylase catalysts:
Sucrose phosphorylases catalyze transglycosylation reactions
on carboxylic acid compounds
This paper is also attached. However, the first two methods are certainly more straightforward.
In this context it is also of interest to note that several glucosides (derived from glucose) of benzoic acid are found as natural products in plants. For more information about this please see the respective Wikipedia entry on "Glucoside" at
It is stated here that "The benzoyl derivative cellotropin has been used for tuberculosis. Populin, which occurs in the leaves and bark of Populus tremula, is benzoyl salicin. Benzoyl-beta-D-glucoside is a compound found in Pteris ensiformis."
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The mass spectrum of benzoic acid will generate the fragment as a base peak (100% relative abundance) of m/z (mass to charge ratio) at?
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105 due to lose of OH
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I have been tasked to design an experiment where i react benzoic acid and thionyl chloride to form benzoyl chloride( which will be used to react with glycine).However, i am unsure of what precautions i need to take note of and how to purify the benzoyl chloride after reaction. I am supposed to use 100mg(0.07874ml) of benzoic acid(which i assume is the limiting reagent?) to react with excess thionyl chloride.
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I agree with the above
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Dear all,
I used TFA/TFAA for aromatic nitration and oxidized the aldehyde to carboxylate group. Now I have the problem, that I must remove TFA next to my product which is an benzoic acid derivative. I read something about removing TFA under Nitrogen stream. Is this the best possibility, or does someone have a better Idea?
I would be grateful for any advices
Julia
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Although you did not specifically mention which product you are getting, it can be deduced that it is a nitro derivative of benzoic acid, and as such, it is almost certainly a solid product that is poorly soluble or insoluble in water. Consequently, I suggest you could carefully drop very slowly your reaction mixture (a solution of your compound in TFA) over ice water (1:15 or 1:20 dilution should work fine). Filter the crystals of your product by Büchne
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What are the reaction conditions for the formation of benzoate and triethanolamine salt in the reaction between triethanolamine and benzoic acid?
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It depends on what you want to do with the product. This is a simple acid/base reaction. You could must mix them neat, but that would likely get quite hot and hard to stir. The easiest would be to mix them in an equimolar ratio in a solvent. They would both dissolve in water, as would the salt. But if you want to isolate the product, water may not be the easiest to remove. You could make a concentrated solution of each in hot water and mix them carefully and slowly to control the exothermic reaction. At the end of the addition cool the water, and the salt should precipitate out. An alcohol solvent should also work if you want to isolate the salt. A good literature search is fairly easy to do and I would recommend that before any lab experiments.
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I was synthesizing the ester by reacting the benzoic acid with the phenyl 4-hydroxybenzoate. After that, i need to remove the protecting group (suppose to be benzyl group but here is benzene) to get back the carboxylic acid. Is it possible to remove the benzene by using the hydrogenolysis method that used to remove benzyl group?
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Impossible. Absolutely impossible to remove benzene with hydrogen. I am an university teacher, lecturer in organic chemistry, if in the exam a certain student write me such a thing, I would break him.
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I want to separate my target compound, 1, 3-phenylene bis[4-{[4-(pent-4-en-1-yloxy)phenyl]diazenyl}benzoate (ester) from the reactant 4-{[4-(pent-4-ene-1-yloxy) phenyl] diazenyl} benzoic acid. I used the ethyl acetate and hexane (3:1) as eluent to separate them.Even though the separation of these two compounds over the silica gel is good (they are two distinctive bands with long distance between them, plus there is only one spot observed on tlc), i realized that the compound is still not pure because the ftir shows the functional group of carboxylic acid. The reactant acid should be stuck at the top of column. Can anyone tell me what happened and suggest me a better way to purify my compound?
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I should have been clearer, 50% of a saturated solution of sodium bicarbonate. Saturate the solution, and then dilute with water. Should work on a small scale. Do a test on a small sample, it could save time.
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Dear all,
I am growing genetically modified S. typhimurium SL1344 cells in a chemically defined medium in a bioreactor. The cells have a deletion in the aroA gene, rendering them auxotrophic for aromatic amino acids, PABA (para-Aminobenzoic acid) and DHBA (dihydroxy-Benzoic acid). Additionally the strain SL1344 is Histidine auxotroph.
For a better understanding of the consumption of these chemicals and to better control the whole system, I would like to be able to measure the concentration of each additive by HPLC. Ideally in a way it can be automated in a later stage.
Since i have not a lot of experience with HPLC (basic knowledge) and i am struggling to find good resources, I would be happy about every input, advice or reference recommendation.
Cheers!
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Dear Simon,
this task is not to easy. Common protocols for amino acid analysis by HPLC includes derivatization of the amines. Keep this in mind for analysis of benzoic acid.
Best,
Simon
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Hello,
I am trying to study the effect of distance between molecules to the Raman spectra. For example, I want to fix the distance between carbonyl oxygen of benzoic acid to one H of water to see the effect of hydrogen bond distance. I tried doing it but the distance always go to 1.9A after optimization. Does anyone know how to do it?
Thanks in advance!
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Hello Marvin,
I just want to include a small comment regarding freezing of bond in Gaussian09. To best of my knowledge in G09 rev C.01 (and above) the modredundant format e.g,
B 1 2 1.5 F doesn't work any more. In newer version of Gaussian it'll ignore the specified frozen length value (1.5) and do a full optimization instead. In older version this input will work fine but not in newer ones. Maybe that is what is happening in your optimization.
In newer version of G09, you first change the respective bond length to the value you want to be frozen at (e.g 1.5 Ang) by Gaussview and then include
B 1 2 F at the end of the file along with opt=modredundant. This will keep the bond length frozen at 1.5 Ang during optimization.
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Hi,
I'm a master student and working on sulfate radical's measurement in the persulfate-based system. Herein, I'm looking for the literature help.
I once read a research paper which determined sulfate radical in an indirect way. In that paper, the authors found that the generated hydroxyl radical had a clear conversion factor with sulfate radical in the persulfate-based system, so they used benzoic acid to trap the generated hydroxyl radical, measured the produced hydroxyl radical, and then converted hydroxyl radical into sulfate radical using the conversion factor. However, I didn't keep that paper and remember little information about that paper either. So if anyone who knows this research paper, please leave me a note. I really appreciate your help!
Best wishes,
Ming Li
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[1] Neta, P.; Madhavan, V.; Zemel, H.; Fessenden, R. Rate constants and mechanism of reaction of SO4 - with aromatic compounds. J. Am. Chem. Soc. 1977, 99, 163–164.
[2] Chenju Liang and Hsin-Wey Su; Identification of Sulfate and Hydroxyl Radicals in Thermally Activated Persulfate. Ind. Eng. Chem. Res. 2009, 48, 5558–5562.
[3] Lindsey, M. E.; Tarr, M. A. Quantitation of hydroxyl radical during Fenton oxidation following a single addition of iron and peroxide. Chemosphere 2000, 41, 409–417.
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I'm conducting an experiment to form acyl chloride by reacting 4-(allyloxy)benzoic acid and oxayl chloride, with DMF as catalyst, at room temperature and dichloromethane as medium. By using TLC method, i found that there is no reaction between my reactants.
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Acid chlorides are very reactive species and it is very possible (and very likely) that the silica of the TLC (which is slightly acidic) could be hydrolyzing your acid chloride. It is not clear from the TLC results that you reaction did or did not fail. They are so reactive that even exposure to ambient atmosphere can hydrolyze them. All solvents and glassware need to be extremely dry (including DMF, which is hydroscopic). So freshly distilled solvents, flame/oven-dried glassware, dry DMF, inert atmosphere, and careful technique are required.
What is your next step? I often do not isolate my acid chloride species and just carry through directly to the next step, keeping the acyl chloride under inert atmosphere the entire time.
Thionyl chloride is a very common reagent, but is also exceptionally toxic. It also generates HCl which may cleave your allyl protecting group. Also common is using isobutyl chloroformate. I have had luck with Ghosez's reagent and strongly recommend that. Also, there are other ways of activating a carboxyl group. Pentafluorophenyl trifluoroacetate can be used to generate the pentafluoropheonl-ester which is highly active (though not as much as an acid chloride) but also air and shelf stable. The PFP ester is also stable on silica gel so you can isolate your activated carboxylic acid if you need too, though again, it is very common to not purify this activated species. There are many, many other approaches.
What do you see on TLC? Only starting materials or new spots? Or consumption or starting materials? Also, what is your next step?
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hi there
I have bomb calorimeter and it reads from 20mg - 200mg of sample weight. I have samples less than 20mg each and am planning to add 50mg benzoic acid to aid combustion. I will then have an estimate of 60mg - 65mg pellet (mix of my samples and benzoic acid) that will go through the bomb machine. I am wondering if the minimum sampel weight reading capacity (20mg) is specifically for sample only or the total sample weigth that go through the machine? in my case is sample plus benzoic acid?
And yes the spiking correction will be done at the end of analysis.
Thanks
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I think it depends on the calorimeter, and you would better consult the manufacturer. for example, we produce calorimeters and we recommend the suitable wight of the fuel and we say that higher amounts must be avoided. in practice one of our calorimeter pressure guages have been exploded because of higher amounts of the fuel.
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How to isolate methyl benzoate
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Thank u
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I am running reactions with benzaldehyde but the reactivity is slow than it has to be, thought it might contaminated/oxidized to benzoic acid. what is best way to purify it ? like wshing it with a base.
thanks
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Method for the purification of benzaldehyde - Google patents. The invention relates to a method for purification of benzaldehyde, in particular of benzaldehyde prepared by oxidation of toluene with a gas containing molecular oxygen. However a more straight forward method is purify benzaldehyde ( which is often contaminated with benzoic acid } by dissolving it in ether and washing with NaHCO3 solution several times. That generally gets rid of any benzoic acid. For more details consult https://www.reddit.com and https://www.google.com - patents
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Topic of interest: Liquid-Solid mass transfer in two phase through mini-fluidized bed.
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Can someone please guide me about the reaction protocol for alkyl benzene to benzoic acid using KMnO4 or any other oxidizing agent.
Thanks,
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You can convert alkyl benzene to benzoic acid by oxidation of alkyl benzene with alkaline KMnO4 . Heat the reaction mix. containing alkyl benzene, aq.Na2CO3 for 3 hrs., cool & neutralize with HCl. The ppt. of acid separates out.
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i want to make the methyl ester of 4-aminomethyl benzoic acid. in all the papers i found it is first dissolved in methanol then SnCl2 or H2SO4 is added. i used a bottle in my lab but it did not dissolve in methanol at all even upon heating. i don not understand why.
can anyone help me and explains me why this could have happened ?
thanks in advance
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It is very possible you are working with a different salt form than the authors of the papers you are referencing. 4-aminomethylbenzoic acid likely exists in a zwitterionic state (CO2- and NH3+) fresh out of the bottle, and will be insoluble in most solvents (including methanol). It is much more soluble in polar solvents when it is fully protonated (CO2H and NH3+). I think it will likely dissolve once acidified with sulfuric acid or similar mineral acids.
I use a similar protocol when making methyl esters of zwitterionic amino acids, first by dropwise addition of 1.2 equiv. of thionyl chloride to a cooled suspension of the amino acid in methanol, then refluxing for a few hours until reaction is complete by TLC or LCMS monitoring.
Hope this helps. Good luck!
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Hello guys
I am really confused.........
The separation of sulfonamides and benzoic acid. I am confused of the reasons of doing these experiment.
is that only due to their structures similarity?
Because when I read about these compounds I found that, sulfonamides are a chemical substances used as drugs for bacteria infections and by the excess of benzoic acid derivatives we can inhibit sulfonamides, in which the sulfonamide will be not enough to stop the bacterial growth. as it is known, Bacteria grows by forming the folic acid by para-aminobenzoic acid. So when sulfonamides block the parar amino benzoic acid and prevent it from forming folic acid the growth of bacteria stops, so the bacteria forms more para amino benzoic acid to overcomes the sulfonamides activit.
Therefore, what is the benefits of the separation of these two compounds if the inhibitions of sulfonamides occurs by the excess of benzoic acid derivatives?
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Thanks for both answers
Mr. Tomas Allende, could please provide me with more information about " Benzoic acid is a good representative of reactants that might be left over"
or any source that can help?
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I am now focusing on the adsorption of benzoic acid on functional carbon nanotubes. Based on my data, the COOH-CNTs is more adsoptive for benzoic acid than OH-CNTs. I know there is Esters can be created between carboxylic and alcohol. Is there also any reaction between two carboxylic functional groups?
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The most efficient bonding is anhydride formation. For this, you need to activate your acid group on CNT and let it react to the benzoic acid. In addition, some physical adsorption can take place by hydrogen bonding between the carboxylic acid groups, which can be maximized if the ratio of CO2H functionality on CNT is very greater than the benzoic acid.
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Dear all,
My aim is to determine the number of zinc atoms bound to a protein. I came across a technique called PAR/PMPS assay which is quite accurate in determining the zinc-protein stoichiometry when compared to its crystal structure.
Most papers use PAR with PMPS but only a very few papers used PAR with DTNB (e.g. Okeley, N. et al., 2003). However, I prefer using DTNB over PMPS as PMPS is a mercuric compound (health hazard issues).
So...
1. What is the advantage of using PMPS over DTNB?
2. What is the mechanism of PMPS in reacting with -SH groups?
3. Can DTNB be used to displace the zinc that is/are bound to cysteines?
From my reading, the mechanism of DTNB is to react with free cysteines but I do not know the actual mechanism of PMPS.
I would really appreciate any suggestions and comments.
Thank you very much for your time,
Luke
*DTNB: 5,5′-Dithiobis(2-nitrobenzoic acid)
*PMPS: 4-(Hydroxymercuri)benzoic acid
*PAR: 4-(2-pyridylazo)resorcinol
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Dear Pongpawan,
I work with cysteine-containing zinc proteins.
Regarding your questions:
1 and 2). Mercury compounds including Hg(II) displace Zn(II) from zinc proteins. Once it is displaced you may measure it using PAR assay, beacuse released Zn(II) easily binds to PAR. DTNB is a disulphide reagent and it reacts with cysteines bound-to-Zn(II). Once cysteines are oxidized Zn(II) disassociates from protein and you may use PAR to quantify Zn(II). In the second approach reaction is relatively slow, depending on Zn(II)-to-protein affinity and structure of the protein and zinc environment. However, based on my experience and hundreds of zinc motifs studied so fat, it is good assay, however you need to ensure that all Cys are oxidized (please measure it in kinetic mode using your spectrophotometer) and make sure that you use proper molar coefficient of PAR. Below is a link to my paper on Zn(II) and other metal ions complexes with PAR reagent. It contains molar coffeicinet for various conditions.
3) As above, answer is yes. In case of metallothioneins that we study, the oxidation takes about 10-20 minutes when you mix DTNB with PAR. When we use the same assay for zinc fingers or zinc finger-like proteins oxidation can takes even more than 1h.
Note, that we usually use two parallel assays, one for quantification of thiols oxidized by DTNB, another to quantify Zn(II) ions. The molar ratio is very informative and allows you to confirm proper protein perpetration and so on ( you know it well).
The first assay is: DTNB in the presence of low concentrations of EDTA. DTNB oxidizes thiols, while EDTA promotes Zn(II) binding. As a result reaction is reactively fast. To calculate thiol concnetration in our sample we use revised molar absorption coefficient 14,150 cm -1 M-1.
The second assay is PAR in the presence of DTNB (link above). PAR acts as EDTA because it is metal ion chelator. Everything is described in my following papers:
if youe have any additonal question please let me know.
Good luck,
Artur
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Hi:
What is the product of thermal decomposition of benzoic acid?
Regards
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Dear Frank:
Many thanks
Adnan
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the other peaks are 1.675 and -3.559. the solvent used was DMSO.
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Probably borosilicate glass (NMR tube) and DMSO adduct with the boronic ester (borononate-sulfoxonium complex).
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I'm currently working to prepare schiff bases derivatives of Tranexamic acid, as there is need to check the completion of reaction TLC is a technique for this purpose but tranexamic acid is inactive to UV because it lacks aromaticity in the ring , so I want to ask about the locating agent for tranexamic in order to compare it with my product.
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There are several ways to derivatize a TLC. One of these which react with the majority of compounds is H2SO4 2N and heat. Since it is also present a nitrogen in the molecule the Dragendorff reagent may be useful. 
To monitor the reaction process you may seed the reaction mixture on TLC together with the reactant/reagent (in different spots) and run the chromatography with a suitable solvent or mixture of solvents. 
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 how benzophenone and phenol removal to reaction mixture?
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For the answer it is necessary to know at least the approximate composition of the mixture
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water soluble gold nanoparticles, the nano gold were bonded with carbon of benzoic acid
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You can perform Boehm titration which is an acid-base titration method used to determine the amount of surface oxygen groups. Although the method is reported for quantification of oxygen functionalities on carbon surfaces like graphene oxide, I think it can work for gold nanoparticles as well.  Please go through the following link:
In one of our works, we had used NaHCO3 following this method to calculate the acidic functionalities on carbon dot surface:
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The presence of sulphur is not allowing hydrogenation to occur
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Tetrahedron Letters 44:733–735, 2003,Please follow this paper and try
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I need to the compund dinitrophthalic acid or diaminophthalic acid in any position substitution .
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Thanks dear Johannes but this acid contain pyridin as salt
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I need to find toxicology information about 4-(butylamino)benzoic acid and 4-(amino)benzoic acid
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Thank you
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We used  carbon dioxide as a supercritical solvent
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Thanks
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Iam doing esterification of hydroxy Benzoic acid with methanol in presence of conc. sulphuric acid.
Please suggest a better esterification catalyst..
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separation of benzoic acid and 2-phenylacetic acid with base can any one suggest me  please?
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what happens to selectivity under strong basic conditions?
why not try bicarbonate under cold conditions?
Finally, how difficult to do a separation column chromatography on alumina of defined basicity (filtration essentially)
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I am doing catalytic oxidations on a larger scale with mcpba as the oxidant. But, everytime after work up with DCM/Et2O and base (triethylamine or NaHCO3), m-chlorobenzoic acid still remains in the solution. Please help.
Also to mention, the desired product is mainly alcohol.
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At bulk preparation levels, the workup is really tricky with remaining m-CPBA! Both the product and the remaining m-CPBA co-exist in the same phase and separation is not complete. Efforts to remove the m-CPBA ends in loss of product which is substantial at higher quantities. The in-mixture m-CPBA can be removed chromatographically through filtration/ adsorption based techniques in separations as well as pH based separation can also be tried.
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I am interested in base-catalysed aldol condensation of Benzaldehyde and Acetone. I think my conversion and selectivity are lower than expected due to the poisoning of the active sites by the benzoic acid contamination in the benzaldehyde. So I want to get rid of the benzoic acid that is already present before I start my reaction (looking for an adsorbent that can selectively adsorb all of the benzoic acid) and also prevent its formation during the course of reaction(looking for a solution to effectively provide inert atmosphere).
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Hi Koushik Ponnuru
Benzaldehyde, suitable for synthesis, is purified in the following way. A 60-g. (58-ml.) sample is washed with two 20-ml. portions of 10% sodium carbonate and then with water. It is then dried over 5–10 g. of anhydrous magnesium sulfate. A few small crystals of hydroquinone or catechol are added with the drying agent. The dry benzaldehyde is decanted through a cotton plug into a Claisen flask; it is distilled under reduced pressure, preferably below 30 mm.
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Usually the melting point of pure compound should be higher than the impure one, because the impurities messes up of the crystalline lattice by blocking their formation and creates irregularities. Thus the intermolecular bonds become weaker, resulting lower heat energy required to break the bond, making the melting points become lower. But why is it different in benzoic acid?
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I also think that benzoic acid is in a state of azeotrope with another body considered as an impurity. otherwise, and outside the azeotrope, the impurities taken as solutes, are used to separate molecules of bensoique acid. in this case the stability of the molecule provided by the intermolecular force is weakened by the breakage thereof, which leads to the lowering of the boiling point of which is proportional. So depending on the concentration of impurity, a quantity of molecules folds against it by only satisfying of intramolecular hydrogen bonds. the general rule of the dispersion of the body A by the body B, or soluté- solvent or  finally, the impurity notion in the body A (when the content is low). Two factors influence the boiling point are the intermolecular hydrogen bonds and polarity of molecules. Here, it may be the question of the intermolecular Foces causing a hexagonal cyclic stability.
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Is reduction of acid group in nitro substituted benzoic acid using lithium aluminium hydride possible and which one is side products?
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With LAH, you reduce the nitro group as well, depending on the conditions, to the aryl hydroxylamine or aniline. I think, borane would do essentially the same. This is not a simple transformation. I would try to convert the acid into the acid chloride (SOCl2-some drops of DMF, reflux for a couple of hours), then dissovle it in isopropanol and add a bit more than the equivalent amount of NaBH4, keeping the flask in the ice bath. If you need a nitrobenzyl alcohol, it is much easier to make it from the corresponding nitrotoluene.
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Hydroxyl group protection of 4-Hydroxy benzoicacid.
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Dear Anju,
The following are the reagents for the protection of phenols since your compound is a derivative of phenol:
Triisopropylsilyl ether (TIPS)
tert-Butyldimethylsilyl ether (TBS, TBDMS)
Methyl ether
Benzyl ether (Bn)
Methoxymethyl acetal (MOM)
[2-(Trimethylsilyl)ethoxy]methyl acetal (SEM)
Please note that some of these reagents might react with the carboxylic acid moiety depending on the conditions.
I suggest that you check every reagent to see if it has selectivity to phenols.
Hoping this will be helpful,
Rafik
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i am preparing lanthenide metal complexes of benzylidene amino benzoic acid. Is there any need to maintain the basic ph-range for the synthesis of benzylidene amino benzoic acids lanthenide complexeses? if it is needed so which basic reagent is suitable in presence of COOH group.
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You can use either NaOH or ammonia to adjust your ligand solution to be a basic solution, then add your lanthanide solution into it. After this, the pH value of the mixture will decrease, then adjust the pH to be weak acidic by slow addition of NaOH or ammonia.
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Using ter-butylamine and Br2 (2:1 ratio) at -70 Celsius and methylene chloride as a solvent.
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Selective ortho-bromination using Rh catalyst is a known scheme. Have a look at the following link on details.
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Good day, I recently conducted esterification process using a benzoic acid derivative and ethanol as its solvent under reflux conditions using sulfuric acid as catalyst. after doing reflux to around 4-5 hours under an oil bath, I monitored the progress of the reaction using Thin Layer Chromatography with a good solvent system. based on the TLC profile, all the benzoic acid derivative was consumed in the reaction process leaving no trace of the reactant but the esterification process produced 2 distinct spots with the spot that has a larger rf value exhibits fluorescence at around 254 nm under a UV-lamp while the other spot (small rf value) does not exhibit fluorescence. I would just like to ask if is there any condensation process that could happen between two benzoic acid derivatives rather than forming an ester product? I was thinking that aside from following an ester-condensation, it would probably follow a Philips-Ladenberg pathway in the formation of Benzimidazoles. I hope someone can help me with this. Thank you so much. and have a good day.
Jerson Lapetaje
Department of Chemistry, College of Science and Mathematics
Mindanao State University- Iligan Institute of Technology
Iligan City, Philippines, 9200
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I suggest you to first isolate both the products and analyse by nmr. I believe the spot which isnt fluorescent must be the required product. As the other guys said just check the purity of the reactants also. Once confirmed may be u can optimize the reaction for better yield. All the best.
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What are the factors influencing the selective oxidation of the benzyl alcohol to benzaldehyde without formation of benzoic acid? Are there any roles for this issue?
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I have been trying to react benzoyl chloride with glutamic acid dissolved in 10% NaOH, but the benzoyl chloride doesn't seem to go into NaOH well, it just stays as an opaque layer at the bottom. When shaken the layer breaks into droplets, but after a while they come together again. After a few minutes acidification with HCl doesn't yield any precipitate. I have tried heating at 50 degree C for a few hours, the organic layer does go into aqueous and acidification gives white precipitate, but it turns out to be benzoic acid. Has anyone run into the same situation before? 
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In addition to above conditions add cationic surfactants for effective conversion
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We need reliable reference samples which are well identified on a botanical point of view. Commercial resins so-called styrax seems to be related to dammar therefore samples that are really authentified by botanical data are requested for comparision with archaeological resins found on artefacts
Thanks in advance Best Jacques Connan
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Bonjour Nicolas,
Nous avons les résines d'Elisabeth Dodinet mais la provenance de sa résine de styrax officinalis est sujette à caution. Quelques autres échantillons seront utilisables car bien identifiés. J'ai d'autres pistes pour avoir de la résine botaniquement prouvée et faire la corrélation avec l'échantillon archéologique.
Cordialement
Jacques
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I am trying for direct condensation of benzoic acid with  Aniline without the acid chloride step,literature/patents mentions that it can be done using a catalyst, however the catalyst suggested as Uranyl chloride or others cannot be used.Can anybody recommend a catalyst?
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  For the condensation of Benzoic acid with Aniline based compound POCl3 /SOCl2 can be used as catalyst. Another way to try the reaction between Benzoic acid with Aniline by heating  in  DCC.
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Can anyone explain the detailed mechanism of IBX synthesis from Iodo benzoic acid and oxone in water?
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There is no evidence of single electron transfer events and even numbered oxidation states of iodine are known to be unstable. The behaviour of oxohalogens in this respect is very well established as is the electrophilic nature of oxygen in peroxysulfate.
Iodosobenzoic acid is a known intermediate that can be synthesised from iodobenzoic and oxone and can also be converted to IBX with oxone.
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I have a solution of 0.03M trimesic acid and benzoic acid. I need to know refractive index of the solution. Are they nearly similar to that of water?
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  1. Shavkat Nizamov is right, it might even shift to the fourth digit for such low molar concentrations. See for instance next links (sorry, not for trimesic acid or benzoic acid) to get an idea: http://chemistry.mdma.ch/hiveboard/rhodium/pdf/chemical-data/prop_aq.pdf and http://www.thefreelibrary.com/_/print/PrintArticle.aspx?id=215925135  
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 i am not getting answer...how to detect and compare a spot of peg6000 along with product and only peg 6000 alone..so kindly suggest me a proper solvent system
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We did the similar work before. Pleas see the paper Tetrahedron Lett. 2004, 113.
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I intend to use SE-30 column for GC analysis of benzaldehyde, benzoic acid and benzyl alcohol. What can be the optimal conditions?
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I use a polar column such as HP-20 (100% PEG) for the analysis, with inlet temperature of 250C and the oven program starting in 150C up to 220C at 10 C/min for 1 minute as final time. If you are using a FID detector, its temperature could be 220C with 40 mL/min of H2 and 400 mL/min of air. depending on the column dimensions (530 µm or 250 µm i.d.) and column length (30 mm for instance), those compounds will be at around 2 min for the benzaldehyde and 4.5 min for benzyl alcohol.
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I have samples of soil organisms that were extracted with benzoic acid and stored in glycerol, and I would like to analyze their d15N and d13C. I would think d13C may be quite affected. However, I can’t find a reference talking specifically about the effects of glycerin and benzoic acid on the d13C and d15N signature in organic tissues.
Thank you very much in advance.
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I'm not sure if there is a standard fudge factor for this. Typically with formalin / ethanol preserved specimens there is a 1 - 2 per mil enrichment in 13C. I suspect that as both the extraction and preservation reagents are organic this will be a lot greater.  would advise you perhaps run a couple of reagent standards with your samples. You could probably do this by treating some combusted GF/F filters with your reagents and running these through the IRMS.
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Hi,
I am working with benzoic acid derivatives containing methyl group and thio compounds. I am doing opt and freq calculations using DFT methods adopting b3lyp and 6-31g* basis sets. I have got first two as negative frequencies. I have done optimization job thrice but still the problem is continuing. How to overcome this problem?
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change in method or basis set for optimization can help you 
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We did an experiment where the benzoic acid was heated at 20 and 30 degrees... We  did this to calculate the benzoic acid's enthalpy of solution with van't Hoff equation.
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The mixing of benzoic acid with NaOH will form the very well known benzoate buffer.
the properties of benzoic acid
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Which is better to start a reaction first amino group (nucleophilic site) or carboxylic group (electrophilic site)?  Any suggestions will be appreciated.
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With this type of zwitterionic compond, it depends on what you want to do, it is better to protect one end before going any further. Carboxylic acid group is not a very attractive electrophilic center. It is better to be detailed as to what you want to or may be the first step. I would suggest starting at the nucleophilic center if your reaction is to be done under milder conditions, However be prepared for a column/crystallization to remove a non-polar side product probably 20% or so.    
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Sometimes it is found that Benzaldehyde shows two spots on TLC. I have been countered this problem by washing the impure Benzaldehyde (solubilize in solvent) by calcium carbonate solution. Further layer separation followed by distillation I obtained the single spotted TLC.
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Hi,
Benzaldehyde is easily oxidized to benzoic acid which can impede its desired reaction and hence it is always recommended to use freshly distilled benzaldehyde.
Simple bicarbonate treatment of benzaldehyde should remove all/any benzoic acid present to the feed Benzaldehyde.
Keeping Benzaldehyde feed in inert atmosphere (oxygen free) will definitely diminish the formation of benzoic acid. 
Addition of oxygen scavenger to the feed Benzaldehyde will also help to diminish the formation of benzoic acid.
Thanks,
Ravindra
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Is substituted benzoyl chloride react with water?
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Dear Chiranjeevi, Benzoyl chloride readily react with water and decompose, so I think for preventing to hydrolysis of benzoyl chloride to benzoic acid in water media, do not neutralize HCl with alkaline solution such as carbonate or ammonia solution. Your first reaction can be do in ether or benzen so HCl leave the reaction as a gas, especially if you increase a bit temprature.
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Amide formation
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DMSO is middle solvent that used for water soluble an insoluble material.
It's a suitable solvent for fatty acids and polysaccharides. EDC, NHS, and chitosan are water soluble materials but benzoic acid is less soluble in water and it's better to used a solvent such a DMSO.
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I´m trying to prepare a benzoate ester of an alcohol but in my NMR spectrum I still have some benzoic acid. I´ve tried to get rid of it washing my organic phase with NaHCO3 but it does not seem to be enough. Does anyone know how to solve this problem?
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Is is likely that you have residues of acyl chloride in the organic phase so that washing is not efective. NaHCO3 is not removing the chloride since hydrolysis should take place first. The remaining chloride turns into the acid progressively with moisture and contaminate your product.
One thing that you can do is to stir your reaction mixture with saturated NaHCO3 solution for a few hours. NaHCO3 is a very weak base so don't suffer to much about ester hydrolysis.
Another useful alternative is to add excess of another alcohol of your choice to react it with the remaining acyl chloride after the conversion of your ROH run over. MeOH will give methyl benzoate that can be removed easily with vacuum distillation if your ester is heavy enough and not so volatile. A glycol or polyol is sometimes useful too because the polyhydroxyester product goes into the water in the work up.
I hope this helps!