[kriggy]

Hi guys, im making o-nitro-cinnamic acid using procedure form Organic Syntheses, Coll. Vol. 4, p.731 (1963); Vol. 33, p.62 (1953).
The procedure says that
...
The crude m-nitrocinnamic acid is suspended
in 300 ml. of ethanol and digested on a steam plate for 2–3 hours. The mixture is cooled and filtered,
and the solid is air-dried. The product, 144–155 g. (75–80%)...

I dont realy understand what the bold part means.. I suppose it means that I suspend the acid in ethanol and then let it slowly evaporate ? Or is it something else?
THanks

[Arkcon]

Not really.  Its just a general term for some sort of non-specific reaction.  You're going to heat it in ethanol for that time period to extract ... something.  Then what remains is what you want.  They could have said reflux, if they wanted to control evaporation.  They could have said "rinsed with" if they wanted you to use cold ethanol.  But instead you've dissolved with mild heat = digestion.

[kriggy]

thank you
however, another question comes to my mind - i doubt we have a steam plate in lab, what is the aproximate temperature that it can be heated on? I mean I´ve seen steam bath and it didnt seem that the water inside was boiling or anyhting, I also doubt that the ethanol should boil in this procedure

[Arkcon]

Exactly so, after 2-3 hrs on a hot plate, for example, 300 mL of ethanol would be gone up the fume hood, and you'd be baking dry solid in a beaker.  If they wanted the ethanol to boil, they would have had to say "reflux".  So a steam bath is for gentle heating, sal to digest a solid for a while, or concentrate a solution -- not to evaporate to dryness.