Picric Acid

[Zappy100]

Hi there,

maybe this is a dumb question and I hope you don't slaughter me for this. I intend to make some picric acid using mega's synthesis. I have all the ingredients except Aspirin which is too expensive in our part of the world. However I have access to pure Acetylsalicylic Acid (hope the spelling is right) as well as Salicylic Acid. I understand tat the first is transformed into the latter during the process. Hence would I not better take Salicylic Acid straight away?

And when using pure Acetylsaliylic Acid would I start adding same to the sulfuric acid or would I have to start with the first step (dissolve in ethyl alcohol)? :(

All feedback is highly appreciated.

Rgds

[metafractal]

Hmm.. now, lets see the checklist:
Newbie (tick)
Posting on first post (tick)
Asking for information (tick)
Failed to do a search (tick)

Uh oh... your fate may depend on the mood of the mods today...

Anyway, yes, it seems that picric acid can be made from salicylic acid.
More information can be found in this (http://www.roguesci.org/theforum/showthread.php?s=&threadid=2132) post. Still, that post does not give a detailed method so this thread may still have some merit in it.

As for you, may the Mods have mercy on you!

Edit: Maybe I'm being a bit harsh, you dont seem totally stupid by the nature of your posts, and I think we may still be in our huggy hippy administration stage. Anyway, your fate not in my hands.

[Zappy100]

I believe you have been a newbie too at one stage? What's the problem posting on first post? May I not ask for information in this forum? I did search a while ago ...

I am just a bit confused because some texts say that the Acetylsalicylic Acid extracted from the Aspirin is then added to the sulfuric acid whilst others say that Salicylic Acid is added. However there is a difference between these acids.

And yes, I hope the mods would forgive a newbie for misbehaving on the first instance ...


Originally posted by metafractal
Hmm.. now, lets see the checklist:
Newbie (tick)
Posting on first post (tick)
Asking for information (tick)
Failed to do a search (tick)

Uh oh... your fate may depend on the mood of the mods today...

Anyway, yes, it seems that picric acid can be made from salicylic acid.
More information can be found in this (http://www.roguesci.org/theforum/showthread.php?s=&threadid=2132) post. Still, that post does not give a detailed method so this thread may still have some merit in it.

As for you, may the Mods have mercy on you!

Edit: Maybe I'm being a bit harsh, you dont seem totally stupid by the nature of your posts, and I think we may still be in our huggy hippy administration stage. Anyway, your fate not in my hands.

[xyz]

It is an unwritten rule here at the forum that you should have 20-30 posts and have gained some respect before you start a new topic. You are also supposed to search before you start a new topic to make sure that it has not been discussed before.

[Zappy100]

My sincere apologies for misbehaving! I was not aware of this unwritten rule. Are there any other (unwritten) rules I should be aware of before committing any further mistakes?

Again I am sorry and will start to gain some respect.

Rgds from the "old world"

Originally posted by xyz
It is an unwritten rule here at the forum that you should have 20-30 posts and have gained some respect before you start a new topic. You are also supposed to search before you start a new topic to make sure that it has not been discussed before.

[Mr Cool]

Salicylic acid can be used, I looked for five minutes with the search engine and found a method reported to give yields over 80%.
If using acetylsalicylic acid, you do not first need to dissolve it in ethanol etc, since that step is used to purify aspirin tablets, which may be impure. If you have pure ASA, add it straight to the H2SO4 and heat.
Try a batch using SA and one using ASA, and work out the cost per gram of TNP using each method. The one which gives you the cheapest TNP is the method that will be best for you. The question "Is method X better than method Y?" is impossible for us to answer in most cases, because it depends on what you have easy access to, and the prices of your chemicals, and your skill in using equipment etc.
I will close this topic, since we have many on TNP already. If you need more information, search those topics, if you can't find what you need, then ask.

Regarding unwritten rules etc., hasn't the no-new-topics-by-newbies rule been written now? Maybe not. I don't think there are any other rules that might catch you out, just be polite and think before you type.

[Zappy100]

Many thanks Mr. Cool! Appreciate your answers and will definitely follow your advise.

Rgds from the old world

Originally posted by Mr Cool
Salicylic acid can be used, I looked for five minutes with the search engine and found a method reported to give yields over 80%.
If using acetylsalicylic acid, you do not first need to dissolve it in ethanol etc, since that step is used to purify aspirin tablets, which may be impure. If you have pure ASA, add it straight to the H2SO4 and heat.
Try a batch using SA and one using ASA, and work out the cost per gram of TNP using each method. The one which gives you the cheapest TNP is the method that will be best for you. The question "Is method X better than method Y?" is impossible for us to answer in most cases, because it depends on what you have easy access to, and the prices of your chemicals, and your skill in using equipment etc.
I will close this topic, since we have many on TNP already. If you need more information, search those topics, if you can't find what you need, then ask.

Regarding unwritten rules etc., hasn't the no-new-topics-by-newbies rule been written now? Maybe not. I don't think there are any other rules that might catch you out, just be polite and think before you type.

[kingspaz]

looks like mr cool forgot to close it :)

work out the number of moles of ASA used in megas procedure and use the same number of moles of SA, which will be a different mass whihc is easy enough to calculate. the reason the ethanol is used is because ASA is soluble in it yet the filler shit in the aspirin tablet is not. therefore you just add the tablets to ethanol, filter out the shit and evapourate the ethanol leaving the ASA. if you have pure ASA already then there is no need.

closing...

[nbk2000]

Here's another unwritten rule...using "Reply w/Quote" for EVERY post. :mad:

It's only for VERY RARE use. Otherwise, just use normal "Post a Reply".

In your case, you'd be better off avoiding it's use altogether.