Sunlight, you may have a point there.
Judging by the smell and also the fact that it looks similar to Safrole decomposing when distilled without Vac, I say it's decomposing acetone. The pufs of smoke also don't get condensed by the condenser, they just waft slowly out of the flask. This is smoke, not H2O vapour(steam).
Prior runs where acetone was not replaced during the reaction resulted in a reaction time that was 10.5 hours instead of 6.5 hours (at 10g Levels). There was also quite a bit more of the impurities and a less pure post reaction product. This made the A/B difficult.
Lili. Did you ever try the NaBH4/Paraformaldehyde/ZnCl2 dimethylation of Tryptamine or any prim. amine for that matter. If so, what were the yeilds? You posted this procedure at some stage and it ended up @ Rhodium.
Here it is, so we're all on the same page:
These one-pot reactions utilize only cheap and (more or less) non-toxic chemicals (no carcinogenic and expensive methyl iodide!). Because of the aprotic, non acidic
reaction and work-up conditions no cyclization to beta-carbolines should occur. The yields after purification are good to excellent (phenylethylamine: 72%, diisopropylamine: 92%, holafébrine: 85%).
Synth. Comm. 25, 2061 1995. Sukanta Bhattacharyya
A mixture of prim. amine (5 mmol) or sec. amine (10 mmol), ZnCl2 (20 mmol) and paraformaldehyde (20 mmol) in 25 ml CH2Cl2 was stirred at RT for 1h under dry atmosphere. NaBH4 20 mmol was then added and the resulting mixture was stirred for 9 h (sec. amines) or 12h (prim. amines). The reaction mixture was then quenched by addition of aqueous ammonia (40 ml, 2 N), stirred for 10 min. and the organic layer was separated. The aqueous part was extracted with CH2Cl2 (1x25 ml) and the combined organic extracts were concentrated in vacuo after drying over anhydrous Na2CO3. Prim. amines were purified by distillation, crystallization or flash chromatography. The sec. amines afforded the pure tert amines without any chromatographic separation.
Hoping this will work as NaCNBH3 is 8X more expensive than NaBH4 in swim's country.