1. Extraction of codeine
Several packets of tablets, sufficient to yield about 2 g of codeine,
are crushed and mixed with water. The mixture is filtered using a
filter pump, Buchner funnel and side-arm flask, to remove tablet binding
agents, diluents and other excipients. The aqueous filtrate is poured
into a separating funnel and sodium hydroxide solution added to make the
solution strongly alkaline. This is then extracted with chloroform
(about 50 ml). The chloroform layer is drained off and evaporated to
dryness using gentle heating (often on a domestic stove). The aqueous
layer containing aspirin and paracetamol is discarded. The codeine base
is recovered as a white crystalline solid for use in
Step 3.
2. Preparation of pyridine hydrochloride
In a beaker pyridine (20 ml) and concentrated hydrochloric acid (25
ml) are strongly heated (to about 190°C) to drive off water. The product
is cooled rapidly to form a waxy white solid which is stored in a
sealed container in a freezer to minimise exposure to moisture and avoid
decomposition.
3. Reaction of codeine and pyridine hydrochloride
The reaction is carried out using a boiling tube which is flame-dried before use. Pyridine hydrochloride (3.5 g) as prepared in
Step 2
is then heated in the tube until it melts and any residual moisture is
driven off. Any resulting condensation on the inside walls of the tube
is wiped off. Codeine base (1.5 g) is added to the tube which is then
stoppered with a rubber bung covered with filter paper and heated until
the mixture starts to fume. Heating is continued until a reddish-orange
colour develops in the reaction melt, which becomes noticeably more
viscous (6-12 min). The contents of the boiling tube are then poured
into a 500 ml separating funnel and the volume made up to 100 ml with
water. Sodium hydroxide solution (10%) is added until the contents of
the separating funnel are strongly basic. As the sodium hydroxide is
added the contents turn milky-brown before becoming clear brown again.
Chloroform (20 ml) is added. After extraction the greyish-brown
chloroform layer is either discarded or put aside for later recovery of
the codeine contained in it. The aqueous layer is poured into a 400 ml
beaker and the pH is carefully adjusted to pH 9 using hydrochloric acid
and narrow-range indicator paper. The solution is rapidly filtered under
suction, using a Buchner funnel and 2 filter papers, to remove a fine,
dark brown residue containing unwanted by-products. The filtered
solution is then poured into a clean beaker and precipitation is induced
by vigorously rubbing the side of the beaker with a 'seeding stick' as
the pH is carefully lowered to 8.5 with additional hydrochloric acid.
(In homebake laboratories a split wooden clothes peg is often used as
the 'seeding stick'.) The product is allowed to settle for at least 5
min before being filtered off under vacuum. The morphine product is
recovered as a powder, ranging in colour from beige to dark brown.
4. Conversion of morphine to heroin
Morphine powder as prepared in
Step 3 is placed in a
spoon. A small amount of acetic anhydride is added and the mixture
ignited. Addition of acetic anhydride may be repeated. A brown or black
tar-like residue remains.
https://www.erowid.org/archive/rhodium/chemistry/codeine.homebake.labs.html
