[DavidF]

Hey all
i'm having troubles with dissolving the next 2 substances:
1) 4-amino benzaldehyde
2) DL-alanine

i've tried almsot every organic solvent out there (polar and non polar), with many combinations of polar liquides (e.g 20% water)
nothing worked.
the 2 just won't dissolve.

anyone has any good experience dissolving the 2 ?

thanks in advance
David

[P]

I've never worked with these compounds so I do not know. However, being a bit nosey, I typed 'DL-alanine solution' and 'amino benzaldehyde' into google.  Have a look at the hits  -  they may help you.   From what I could see, (you would probably make more sense of it than me as I haven't the time at the moment to read it thoroughly) from skim reading bits from hits, is that the alanine should be soluble in water and the amino benzaldehyde in hydrogen peroxide.

[DavidF]

thanks for the response. i've googled it a few times but none of the hits helped...
btw - i've managed to dissolve the Alanine.. with 1/3 water and 2/3 DMF.
as for the 4 amino benzaldehyde, never seen anything like it.. it just wouldn't dissolve.. i know hydrogen peroxide could dissolve it, but i need an organic(or a mixture with max 30% water) solvent because i'm carrying a reaction afterwards with it, so obviously H2O2 is of no good...

[AWK]

Alanine is soluble in water only. Its hydrochloride is slightly soluble in alcohol.

[sjb]

What sort of consistency is your 4-aminobenzaldehyde?

Could the problem be related to self condensation, so that you in fact have a poly imine or similar?

S

[agrobert]

What sort of consistency is your 4-aminobenzaldehyde?

Could the problem be related to self condensation, so that you in fact have a poly imine or similar?

S

These were my first thoughts as well.  Are you certain that your reagent is has not gone bad?

[DavidF]

well i don't think it has gone bad... but i can't be sure
it looks pretty usual nothing special that could alert

what solvent should have dissolved it ?

[sjb]

Can you do a melting point determination?

Org Synth, 31, 6 1951 suggests that this (p-aminobenzaldehyde) melts at around 68-70°C and is reasonably soluble in EtOH / H₂O.

http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv4p0031

S

[russellm72]

Try DCM-MeOH (75:25).

Do you have a sonicator?

R.

[HP]

For both substances you may try disolve in 85-90% HCOOH or in neat formic acid as well. Trifluoracetic acid may work as well..