I keep running into a weird issue with making TNR, after sulphonating resorcinol, I get no exotherm on the addition of HNO3, instead it
tends to "dump" all of that heat after additions (which caused a nitration runaway on my first attempt) I managed to do the synthesis successfully
once without the runaway reaction, but I had the same no-exotherm problem on my latest attempt, which made me quench the reaction mix instead of
carrying on.
Am I "overcooling" the reaction mix or am I simply too fast with my additions? I'm following a scaled-down version of the Powerlabs prep for it and I
can post it here if needed.Tsjerk - 1-11-2021 at 03:59
I don't know this specific reaction, but it sounds like overcooling indeed. The reaction needs some temperature to proceed and when it does get up to
speed, either because of a higher temperature or a higher concentration of nitric acid, there is already too much nitric available to keep the
temperature under control. I would raise the temperature until you do see the exotherm before adding more nitric.
[Edited on 1-11-2021 by Tsjerk]xonu - 1-11-2021 at 06:57
Guessed so, I once started the addition outside the icebath and only started cooling when the exotherm started, and it worked out fine with no runaway
during the next step.caterpillar - 1-11-2021 at 20:08
My first attempt to prepare TNR failed- I tried just like I did it with phenol. But resorcinol after contact with sulfur acid turned to stone. Later I
made TNR, using a two-stage process- nitrosation and then nitration with diluted nitric acid. No concentrated acids at all. xonu - 2-11-2021 at 00:22
Weird, mine forms a dark red thick goop that feels like a very viscous jam, it thins out on addition of HNO3caterpillar - 2-11-2021 at 04:42
