The methylenation procedure in which polymerization is inhibited by controlling the concentration of the dihydroxybenzene dianions is not that novel at all, see
https://www.thevespiary.org/rhodium/Rhodium/methylenation.bonthrone-cornforth.html
SWIM had a really interesting dream one night, he thought he would like to share it with the bees. In his dream he saw an man wearing a white lab coat doing the following things:
A 250 mL three-neck RBF was fitted with a reflux condenser and a thermometer. The third neck is stoppered with a rubber stopper for addition of solid. The flask is charged with 12.5 g anhydrous Na2CO3, 13 mL CH2Cl2 (260% excess), 27.5 mL DMF and 0.5 g anhydrous NaI to act as a nucleophilic catalyst.
This mixture is heated to boiling (75 C) on a water bath and 6 g of 5-hydroxyvanillin (recrystallized from boiling toluene; Note 1) is added over 3 h, the reaction mix is heated for 6 h more, then an additional 4 g of 5-hydroxyvanillin is introduced during a period of 3 h (Note 2) Heating is continued for 12 h (total reaction time 24 h). The internal temperature rises gradually, reaching 98-100 C by the completion of the addition of substrate and staying there for the rest of the reaction time.
The flask is cooled, reaction mixture (black in color) diluted with water, a little dil. NaOH added and extracted 4x with CH2Cl2. The extracts are washed with water, 2x with dil. NaOH, then again with water. The extracts are dried on MgSO4 and solvent is distilled off leaving a black residue that crystallizes in the flask. This is dissolved in hot ethanol (100 mL), filtered through a fluted filter paper from some insolubles and cooled in the freezer. The crystals are separated and the mother liquor concentrated. Total yield: 5.8 g, 53% of light brown myristicinaldehyde, mp 129-131 C (pure enough for practical purposes, another recrystallization from ligroin affords off-white crystals having mp. 131-133 C, downside is that 100 mL 80-100 C ligroin dissolves less than 2 g of aldehyde)
The old man seemed to mumble to himself in SWIM's dream, this is what he could understand:
Note 1. Unrecrystallized black tarry 5-OH-vanillin has been used successfully, the reaction solution however must be filtered from some tar after dilution with H2O.
Note 2. The old man's actual plan was to add the entire 10 g over 8 h but he fell asleep after 3 h.
Sorry if this is old news. Nonetheless it's a convenient and quite OTC procedure as KF is watched in many countries and so are PTC's. The yield certainly could be improved.
1. PiHKAL #134 (MMDA-3a)
2.
https://www.thevespiary.org/rhodium/Rhodium/methylenation.bonthrone-cornforth.html
Wraith
P.S.: Can anyone provide SWIM with the vapour pressure of myristicinaldehyde at 100 C, or empirical data on how much steam is needed per g when doing a steam distillation?