having problem with cooking pyridine Hcl and codeine

gomer · Sun Aug 07, 2005 10:16 am

Just say some1 was cooking codeine extracted from otc's with pyridine Hcl what could be causing the reaction mixture to turn black almost as soon as the codeine is added to the boiling tube.The pyridine Hcl is prepared by heating pyridine with hydrochloric acid which the bottle strength says contains 300g/L hydrochloric acid to a temp of 196 deg celsius.Is the acid I am using strong enough?After cooling it turns to a waxy substance ,should this be soft or quite hard?When the pyridine salts are added to a boiling tube and stoppered with a filter covered bung and heated all seems well although it is a little murky in colour when it starts to bubble.But as soon as the codeine which is clean and white is added to the hot reaction mixture the whole lot turns black almost instantly.I know I am supposed to cook it until it turns a orange to cherry red colour and a thicker viscosity is noticed but this is not possible when it turns black almost straight away.Any help would be much appreciated.The codeine is extracted by vac filtering out the solids from the pill and water mixture and adjusting the ph to 12 and washing 3 times with 30ml of chloroform each wash.After evaperating the amount of codeine by weight comes close to matching what the pills add upto so I am sure the codeine is good and clean.

Smack · Sun Sep 25, 2005 2:42 am

Interesting question.

Maybe you over-eated the Py.HCL before adding the codeine base. I believe you just have to heat it sightly till it melts, and then when melted, you should add the codeine. That's what I assume anyway.

I hope someone with a greater knowledge and experience will answer that question.

N.J