The usual way seems to be heating a mix of Niacin and catalyst (I used basic copper carbonate) and limiting temp at the heating mantle to 250 deg C.  I put a K-type thermocouple between the mantle and distillation flask.  After 2 hours the head temp was only 60 deg C and nothing was happening (actually something was happening the Niacin was melting with drops forming in the head).  So I raised the mantle temp and started getting distillate.

Problem is the Niacin sublimes as a white vapor passing over to the receive flask, the Niacin in the rxn flask is burning and recrystallizing in the rxn flask.  A loss of yield.

Do I have to just let it sit at 250 deg C mantle temp?

8 hours ago, Bkhan3 said:

The usual way seems to be heating a mix of Niacin and catalyst (I used basic copper carbonate) and limiting temp at the heating mantle to 250 deg C.  I put a K-type thermocouple between the mantle and distillation flask.  After 2 hours the head temp was only 60 deg C and nothing was happening (actually something was happening the Niacin was melting with drops forming in the head).  So I raised the mantle temp and started getting distillate.

Problem is the Niacin sublimes as a white vapor passing over to the receive flask, the Niacin in the rxn flask is burning and recrystallizing in the rxn flask.  A loss of yield.

Do I have to just let it sit at 250 deg C mantle temp?

I thought it was copper chromite that was commonly used as a decarboxylation catalyst.

Yes, that is the catalyst of choice here - can also use basic copper carbonate and I had some. I have to make some of the other which I will do and try this again.

Thanks.