GreenD
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A challenge... how to get this product
Whether its a challenge to you guys I'm not sure.
Synthesizing this.
The 2,2-dimethyl phenylacetic acid is available, but I'm not sure (yet) if it is prohibitively expensive.
Acquiring that, the phenylmethane sulfonic acid (or a-toluene sulfonic acid) isn't readily available.
I've done a formation of a nitrile before, using CuCN acting on a phenyl halide. So I know that would be possible... but I'm having trouble finding
starting materials, or seeing a possibly easier method... I'm not very familiar with many carbon-carbon forming reactions that are easy to carry out.
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AndersHoveland
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I am probably wrong here, but I think there might be a chance that the cyano- group in 4-cyanotoluene might activate the methyl group to nucleophilic
attack, since it is in the meta- position.
NC-C6H4-CH3
[-]N=C=C6H4=CH2 H[+]
I am not saying it actually tautomerises, just that the methyl group might be more vulnerable to oxidation or nucleophilic attack. If you managed to
get it to condense with SO2Cl2, the rest should be easy.
NC-C6H4-CH2-SO2-Cl
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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GreenD
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That would be news to me, I would have never even considered that...
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GreenD
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To clarify most of the literature creates the sulfate group by reacting a 4-nitrile-benzyl bromide with sodium sulfate
then they create the p-cyano benzyl sulfyl chloride with oxalyl chloride or thionyl chloride...
Interesting.
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Nicodem
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Quote: Originally posted by GreenD  | | To clarify most of the literature creates the sulfate group by reacting a 4-nitrile-benzyl bromide with sodium sulfate |
That is nonsense. First of all, there is no sulfate group in the structure. There is a sulfonyl group being part of the imide moiety. Secondly, benzyl
bromides do not react with sodium sulfate and even if they formally could, they would utmost give sodium alkyl sulfates rather than sulfonates.
Benzylsulfonic acids can be obtained by nucleophilic substitution of benzyl bromides with (bi)sulfites (S-alkylation of sulfite). Benzylsulfonyl
chlorides can be obtained from these, or alternatively by the oxidation of benzylthiols, S-benzylthiosulfates, benzylthiocyanates or S-benzylthioureas
with chlorinating reagent in aqueous media. There are plenty of information and references about this on this forum, which you can find by UTFSE.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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AndersHoveland
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Nicodem, I think GreenD may be right. Decarboxylation may likely be possible, and would yield the sulfonate. I think he might have made a mistake and
meant to say 4-nitrile-benzoyl-bromide, not benzyl. The two are different.
Edit to above: nevermind, I realised I am wrong here  ... unless GreenD is
content to have 4-nitrile-phenyl-sulfonate.
As for reacting the sodium 4-cyano-benzene-sulfonate with sulfuryl chloride, I have seen this reaction done with organic phosphorous chlorides. PCl5
can displace a hydroxyl group on another phosphorous atom in an organo-phosphorous compound and displace it with a chlorine group. I am sure it would
work with the sulfur here also.
I wonder if thionyl chloride could perhaps be refluxed with benzyl alcohol to give the chlorosulfonate? I mean, the sulfite might be able to
isomerize. Nitrite esters are known to be able to isomerise to nitro groups under strong heat, for example.
C6H5-CH2-OH + SOCl2
C6H5-CH2-O-SOCl
C6H5-CH2-SO2Cl
[Edited on 12-1-2013 by AndersHoveland]
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GreenD
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| Quote: Originally posted by Nicodem | | Quote: Originally posted by GreenD | | To clarify most of the literature creates the sulfate group by reacting a 4-nitrile-benzyl bromide with sodium sulfate |
That is nonsense. First of all, there is no sulfate group in the structure. There is a sulfonyl group being part of the imide moiety. Secondly, benzyl
bromides do not react with sodium sulfate and even if they formally could, they would utmost give sodium alkyl sulfates rather than sulfonates.
Benzylsulfonic acids can be obtained by nucleophilic substitution of benzyl bromides with (bi)sulfites (S-alkylation of sulfite). Benzylsulfonyl
chlorides can be obtained from these, or alternatively by the oxidation of benzylthiols, S-benzylthiosulfates, benzylthiocyanates or S-benzylthioureas
with chlorinating reagent in aqueous media. There are plenty of information and references about this on this forum, which you can find by UTFSE.
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When I go back to work I'll show you the sources... They have the reaction in >90% yield in more than 1 paper.
CN-C6H4-CH3 -> CN-C6H4-CH2Br -> CN-C6H4-CH2SO3H -> CN-C6H4-CH2SO3Cl
is the reaction scheme that I looked up, and confirmed in multiple sources.
Step one was done by NBS
Step 2 done by Na2SO3, and a catalyst
Step 3 done by SOCl2
"Secondly, benzyl bromides do not react with sodium sulfate and even if they formally could, they would utmost give sodium alkyl sulfates rather than
sulfonates. "
Perhaps I misread and it is some sort of sulfite, not sulfate, but I thought I had read sulfate... I'll double check tomorrow.
[Edited on 14-1-2013 by GreenD]
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smaerd
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Post the papers so we can follow along, or atleast citations so we can read up. I'm pretty curious about this on a pedagogic level.
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GreenD
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Thank you Nicodem, you corrected my obvious mistake. I am not familiar with sulfur compounds at all, so my vocabulary with them is also lacking, I was
really unaware of sulfites & sulfates, I was seeing the two as the same, 1 mistake of a million more to come, but I'm glad to be learning.
From this paper:
Indole Cytosolic Phospholipase A2 α Inhibitors: Discovery and in Vitro and in Vivo Characterization of
4-{3-[5-Chloro-2-(2-{[(3,4-dichlorobenzyl)sulfonyl]amino}ethyl)-1-(diphenylmethyl)-1H-indol-3-yl]propyl}benzoic Acid, Efipladib
"General Procedure for Synthesis of Sulfonyl Chlorides A
Step 1. A mixture of halide (1.0 equiv) and sodium sulfite (1.2 equiv) in H2O (0.1 M) and EtOH (0.2 M) was heated to reflux overnight. The mixture was
cooled to room temperature and concentrated until a precipitate began to form. The product was collected by filtration and azeotroped with toluene.
The resulting solid was used in the next step.
Step 2. To a suspension of the sodium sulfonate (1.0 equiv) in CH2Cl2 (0.1 M) were added DMF (0.7 equiv) and SOCl2 (3.9 equiv). After 1.5 h, the white
suspension was concentrated and azeotroped with toluene. The sulfonyl chlorides thus formed were used without further purification."
It is, indeed a sulfite, not a sulphate. Sulfate? ... oh boy 
The problem, however with ALL of this, is whether this reaction will occur:
I'll begin searching and hopefully have an answer.
Edit:
Looks like sulfonamides are tricky to make in high yield, most lit. sites a max of 60% yield. Some give higher yield, but the amide is subsituted or
cyclical, giving it greater nucleophilicity.
[Edited on 14-1-2013 by GreenD]
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GreenD
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The alternative reaction, a p-sulfamoyl-cyano compound could be reacted with the carboxylic acid using DMAP and EDC catalyst as I referred to in my
other post.
Sulfamide chemistry is really new to me... all sulfur chemistry, really.
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GreenD
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Sulfonamide formation from "Ammonia"
I read a paper that was wonderful enough to describe the formation of a sulfonamide as
"Treating the sulfonyl chloride with ammonia"
Would bubbling ammonia through a sulfonyl chloride solution produce such results?
Anyone have organo-sulfur compound experience?
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Nicodem
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Why would you want to use gaseous ammonia?
Aqueous ammonia solutions of up to 25% are pretty much ubiquitous in every lab. Much more practical for use than ammonia gas cylinders.
PS: You have been told already numerous times that this is a science forum and you still post like you would be having a chat in a pub. Saying "I read
a paper..." without giving the reference is an offence to any (amateur) scientist reading your post!
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Nicodem
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GreenD
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| Quote: Originally posted by Nicodem |
Why would you want to use gaseous ammonia?
Aqueous ammonia solutions of up to 25% are pretty much ubiquitous in every lab. Much more practical for use than ammonia gas cylinders.
PS: You have been told already numerous times that this is a science forum and you still post like you would be having a chat in a pub. Saying "I read
a paper..." without giving the reference is an offence to any (amateur) scientist reading your post! |
Are you saying I should mix aqueous ammonia with a sulfonyl chloride to get the sulfamide??
AQUEOUS? Ammonia?
Im on and off my academic server so sometimes I do not have access to the papers, when I post.
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chemrox
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I don't like posts without refs. Cite the f**king reference (CTFR) please. What's the problem with bringing a reference to school?
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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SM2
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Why is a ref. mandatory for some of you guys? Especially when the poster assures that there is no additional info. to be gleaned from the
ref./patent? There are many reasons we ALL KNOW why some with NOT to include the actual reference. Everything, BUT the reference. A big one which
pops into my head: confidentiality. It's like the Inquisition of the Reference Pre-Requisite!
Green-D: your compound indeed exists, at least, it is electronically capable of existing as a relatively stable compound. But there are numerous
ways to get there.
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watson.fawkes
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| Quote: Originally posted by SM2 | | Why is a ref. mandatory for some of you guys? Especially when the poster assures that there is no additional info. to be gleaned from the
ref./patent? There are many reasons we ALL KNOW why some with NOT to include the actual reference. Everything, BUT the reference. A big one which
pops into my head: confidentiality. It's like the Inquisition of the Reference Pre-Requisite! |
Citing
references is the first-line defense against bullshit. "Poster assurances" and "confidentiality" are antithetical to science. Science is a group
effort, not an individual one. It emphasizes repeatability, not "trust me, it works". No scientist should take a result purely on faith, nor should
they consider confidential results to be part of the progress of science.
This is "Science"-madness, not "Elite-alchemy"-madness. The biggest part of the transition from alchemy to chemistry was not the experimental results,
which Boyle, indeed, set back a few years, but rather the principle of scientific publication, which started with the Philosophical Transactions of
the Royal Society.
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GreenD
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Guys this is a science board, not a chat board.
I specifically put this in the beginning threads so Nicodem wouldn't be after me for references.
I didn't think all the references I alluded to would be necessary, since I extracted the only relevant parts.
Next I will be posting my actual synthesis trial and error, I'm sure there will be much error, so I will try to keep it minimal, but I thought maybe
someone on here would have some experience with sulfamide chemistry (which I haven't seen yet) and I thought maybe someone would be interested in it -
which at least one person was.
I'm currently pursuing a PhD in a non-chemistry field, and the experience in my lab is nill, and this board is a great resource. I'm just warning you
all that my post may get lengthy with questions, as I embark on this quest.
[Edited on 18-1-2013 by GreenD]
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UnintentionalChaos
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Just a thought here. Sulfonamides are fairly acidic, moreso than carboxylic acid amides. Reportedly, they are nearly as acidic as phenols. I would
expect the acylation of (4-cyanophenyl)methanesulfonamide with 2,2-dimethylphenylacetyl chloride in the presence of a base to be a much better
approach than treatment of 2,2-dimethylphenylacetamide with (4-cyanophenyl)methanesulfonyl chloride.
The 2,2-dimethylphenylacetic acid might be a bit complex to prepare. One could treat methyl benzoate (or acetophenone) with methylmagnesium iodide in
a grignard to form 1-methyl-1-phenylethanol. As a tertiary alcohol, this could be readily converted to the alkyl chloride, turned into the grignard
and poured over dry ice to form the phenylacetic acid. Reflux with SOCl2 would get you the chloride. Oxalyl chloride can probably also be used, I am
just ignorant of the conditions needed.
As for the formation of sulfonates from sulfites and alkyl halides, apparently that is called the Strecker sulfite alkylation. Honestly, this is the
first time I've ever heard of it, but it looks like it could be quite handy.
[Edited on 1-18-13 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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GreenD
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| Quote: Originally posted by UnintentionalChaos | | Just a thought here. Sulfonamides are fairly acidic, moreso than carboxylic acid amides. Reportedly, they are nearly as acidic as phenols. I would
expect the acylation of (4-cyanophenyl)methanesulfonamide with 2,2-dimethylphenylacetyl chloride in the presence of a base to be a much better
approach than treatment of 2,2-dimethylphenylacetamide with (4-cyanophenyl)methanesulfonyl chloride. |
That is my new plan, however I do not know if it is as simple as using a base. My proposed reaction would be a coupling reaction using DMAP and EDC.
[ | Quote: Originally posted by UnintentionalChaos |
The 2,2-dimethylphenylacetic acid might be a bit complex to prepare. One could treat methyl benzoate (or acetophenone) with methylmagnesium iodide in
a grignard to form 1-methyl-1-phenylethanol. As a tertiary alcohol, this could be readily converted to the alkyl chloride, turned into the grignard
and poured over dry ice to form the phenylacetic acid. Reflux with SOCl2 would get you the chloride. Oxalyl chloride can probably also be used, I am
just ignorant of the conditions needed.
As for the formation of sulfonates from sulfites and alkyl halides, apparently that is called the Strecker sulfite alkylation. Honestly, this is the
first time I've ever heard of it, but it looks like it could be quite handy.
[Edited on 1-18-13 by UnintentionalChaos] |
I have found that the 2,2-dimethyl phenylacetic acid is available at the semi-reasonable price of 50$/gram. I only need a few grams to last for some
good amount of time.
// Reaction for DMAP & EDC:
To a stirring solution of the benzoic acid (1.2 equiv) in dry CH 2Cl2 (10 mL/mmol), the phenylsulfonamide (1.0 equiv) was added in one portion
followed by EDC (1.2 -1.5 equiv) and then DMAP (1.2 equiv). The mixture was vigorously stirred under nitrogen for 16 h and concentrated under reduced
pressure, and the residue was partitioned between EtOAc and H 2O. The organic layer was washed with 1 N HCl (four times, 20 mL/mmol), and then, the
combined aqueous phases were extracted with EtOAc (2 x20 mL/mmol). The combined organic layers were washed with H 2O and brine, dried over Na 2SO4,
and concentrated in vacuo. The residue was subjected to silica gel chromatography or crystallization if necessary.
Its nice, except that you need molar eq. of DMAP and EDC.
In this paper:
http://pubs.acs.org/doi/abs/10.1021/jm030594r
I'm going to write up a reaction scheme... One of the steps worries me however, as it says "Caution was taken as to prevent an exothermic runaway" :\
I'm already a bit shy of chemistry as it is!
[Edited on 18-1-2013 by GreenD]
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GreenD
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Separate compound, but...
Would a reaction with thionyl chloride break the sulfamide bond? I'm worried that the carbonyl of the amide may react, breaking the bond.
[Edited on 19-1-2013 by GreenD]
[Edited on 19-1-2013 by GreenD]
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GreenD
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Chlorination Questions
I have come across perhaps a dozen papers describing chlorination of carboxylic and sulfuric acids (sulfates) using SOCl2 or PCl5. I have some
questions/comments that I'd like some help with (numbered).
1. PCl5 & SOCl2 - From my understanding these are relatively interchangeable.
Now, with SOCl2, the addition of a small amount of DMF catalyzes the reaction. Not sure if it also does with PCl5
Upon addition of DMF to my solution of P-Cyano-benzylsulfate and SOCl2, the solution began to vigorously boil, or give off gas,
although no pressure accumulated.
2. But the color changed from chalky white-yellow to a deep blood red. Why is this?
Three sources have all independently said that once chlorination is complete (or after refluxing for multiple hours) the reaction solution is added to
ice water, and filtered.
3. Why does my product (p-cyano-benzylsulfochloride) not react with ice water to give the starting material again?
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Deathtillation
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PCl5 and SOCl2 are interchanggeble in preparation of acid chlorides. I used both to make PhSO2Cl from dry sodium salt of benzenesulfonic
acid in presence of small amount of DMF.
This is normally observed when you add the catalytical amount of DMF to a suspension or solution of some sulfonic or carboxylic acid in SOCl2 the gas
is evolved due to formation of Vilsmeier complex and chain-like reaction, leading to formation of acid chloride.
As your sulfonyl chloride is solid, besides it's low reactivity towards water, (which this is common for all sulfonyl chlorides including ones liquid
at normal condition - see examples os TsCl or BsCl in the literature like Vogels - they all are cold water resistant, though they may hydrolize very
slowly, this process in considerably catalyzed by bases) your chloride is totally protected from water by it's insolubility - lower contact area where
the hydrolysis is theoretically possible.
I cannot say anything about color changes, though I believe that's normal.
Though your isolation method is almost harmless to your acid chloride, I'm not sure whether it is the only way to quench the reaction mix with water.
If you dont use PCl5 you dont end up with any non volatile by-products, like phosphorous acid or POCl3 so you dont need to bother with that water
quenching of rm. This will only waste your time.
I would recommend not to bother with quenching rm but instead simply distill off the excess thionyl (it can be recovered) and dry the acid choride
in vacuo to remove the traces of HCl and SOCl2, then recrystallize if neccessary.
[Edited on 15-5-2013 by Deathtillation]
[Edited on 15-5-2013 by Deathtillation]
[Edited on 15-5-2013 by Deathtillation]
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GreenD
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Thank you very much deathtillation - that was very informative. Below is my procedure. (Replaced PCl5 with SOCl2)
My experiment as outlined on page 33 of http://www.jstor.org/stable/82398
p-(-Sulphonamidotolamidine hydrochloride (XIV). The nitrile required for the preparation of this amidine was obtained as follows. p-Cyanobenzyl
bromide (19.6 g.) (Case I925) and sodium sulphite heptahydrate (25-2 g.) were refluxed with water (50 c.c.) forhalf an hour, when the nitrile rapidly
dissolved. On cooling, sodium p-cyanotoluene-o-sulphonate (225 g.) separated as a microcrystalline solid, m.p. about 309?. (Found: on solid dried at
110? in vacuo, N,6-7; S, 14-2. C,HO63NSNa requires N, 6-4; S, 14-6 %.) This sodium salt (21-5g.) was mixed intimately with finely powdered phosphorus
pentachloride (20-7 g.) and moistened with a few drops of phosphorus oxychloride. After 3 hr. at 75-80? on the water-bath, the mixture was added to
ice-water, when an oil separated which eventually solidified. It was collected, washed with water and then shaken with 16 % aqueous ammonia solution
(160 c.c.). The required p-cyanotoluenesulphonamide (11 1 g.) was collected after 12 hr.; it separated from 50 % alcohol in microscopic short laths,
m.p. 216?. (Found: C, 48-6; H, 4-4; N, 14-1. Calc. for C8H8O2N2S: C, 49-0; H, 4-1; N, 14-3 %.) Miller et al. (i940) record m.p. 216-217? for this
substance prepared by an alternative method.
My oil came out orange, and I let it stand over ice water for about 15 minutes, at which point I returned to find a VIOLET colored solid. I mean
serious lilac color. I've never seen something like this in organic chemistry! Its quite pretty.
However I am not in the least bit confident in what I have. My only assumption is that since I added a large deal of DMF, way more than necessary for
a catalytic amount - nearly 1eq to my starting material - I believe I've formed some kind of adduct, for I would not understand the color in any other
way.
So at this point, my next step would be attempt to solvate this product and run it through a small column of silica and see if I can separate the
color from the intended sulfonyl chloride. If ANYONE has an idea what I've made, I'd really appreciate additional pointers.
Again thanks deathtillation, that was really useful.
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Nicodem
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GreenD
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Another Question (Even if it falls on deaf ears):
From above:
This sodium salt (21-5g.) was mixed intimately with finely powdered phosphorus pentachloride (20-7 g.) and moistened with a few drops of phosphorus
oxychloride. After 3 hr. at 75-80? on the water-bath, the mixture was added to ice-water, when an oil separated which eventually solidified. It was
collected, washed with water and then shaken with 16 % aqueous ammonia solution (160 c.c.). The required p-cyanotoluenesulphonamide (11 1 g.)
was collected after 12 hr.; it separated from 50 % alcohol in microscopic short laths, m.p. 216?.
The sodium salt is insoluble in 15-20% aq ammonia, so there are very fine particles floating around in the solution.
My question is, however, in context to the bold: I am assuming that they are collecting the solid via filtration, and then recrystallizing
from 50% alcohol, but I don't know how. My first assumption would be upon heating and cooling, the product crystallizes out of 50% alcohol solution,
but... this is not what they say.
Anyone have another take on this?
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bfesser
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Thread Split
15-7-2013 at 07:36 |
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