Some helpful tips from my friend ciphir who was part of the original thread over at the vespiary:
Overhead stirrer is essential, magnetic stirring cannot cope, extremely vigorous stirring is required for the initial part of the reaction when the C=C double bond is broken,
the solution will turn from a yellow to a white colour when this part is over.
The second part, the reduction of the nitro group to amine, goes better with addition of the copper chloride dihydrate (CuCl2.2H2O) solution as fast as possible,
it foams a lot so you can attach the output of an electric vacuum booster pump to the gas port and apply slight positive pressure of air to control the foaming.
Also you can attach a anti-splash straight adapter between the reactor vessel and the condenser assembly to prevent foaming blowing out the top.
Instead of 10 to 20% molar equivalent of copper chloride can also try using you can use a 8% molar equivalent of copper chloride dihydrate and a 8% molar equivalent of copper sulphate pentahydrate, so you are still providing the Cu nanoparticles or NaBH4-Cu complex but with reduced foaming. (Note: 1000g of P2NP means this is a 6.12 mole reaction (1000/163.2 g/mol), so 8% molar equivalent is 0.49 moles of each copper salt.)
Add a saturation amount of common table salt (NaCl) to the water extraction, because it has a higher affinity for water the last load of amine molecules get pushed out of solution and will enter the non-polar layer.
Aside:
I know Ciphir, normally after conversion of the nitro to amine, adds glacial acetic acid until pH=4 to push the amine into the aqueous layer (any fizzing is the quenching of any excess NaBH4, use less next time). Strip off the IPA up to about 97C, then basify to pH=11 with NaOH, now steam distil with a wall paper steamer connected to an inlet into centre of reaction vessel.
Using a 2L sep funnel, collect the water (lower layer) for extraction, save the non-polar layer as this is pure freebase oil of the amine.
Extract aqueous layer 3 x with DCM or another non polar solvent that's immiscible with water, add salt to water layer for final extraction.
Combine organic phase and extracts and distill off NP solvent.
Mix amine oil with 5 parts anhydrous isopropanol (IPA), mix sulphuric acid with 2 parts anhydrous IPA, add until pH=9, then very carefully add until pH=6.7, use buchner funnel to filter amorphous white solid (no crystallisation possible with this amine) vacuum dry solid in funnel.
Check pH of filtrate add more acid if necessary, place in freezer for second crop, repeat process until no more amine sulphate precipitates.
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