A recent MM Wacker provided for a delightful experience: the best yield ever! Now all I need to figure out is why it went so well.
The methanol was a "new brand", 99.99%.
2.5 grams (instead of 2) PdCl2 were used, also a "new brand", lab grade 99+%.
190 ml of Safrole (freeze fractionated) were used (poured a bit too much)
When dripping in the Safrole, the addition funnel clogged after about 50% of the Safrole was added. Over an hour had elapsed already, so when discovered, the additional Safrole was added over another 45 minutes. The temperature was carefully monitored and never got above 69 C. Total addition time close to 2 hours.
Workup: The 10% HCl was added to the sep funnel first, then the Wacker added. The oil that formed at the bottom was sepped off immediately, before even adding DCM. Then usual 500, 250,200 ml DCM was added to sep etc., and added to Oil.
All fractions prior to Ketone (residual DCM, H2O, Methanol) were dumped during the vacuum distillation. Final distillation yielded 150 ml Ketone.
Now trying to figure what gave the great yield.
As I mentioned in first post, pure Palladium formed a mirror coating in the reaction flask, as opposed to the usual Pd Black colored residue.
Could the excess of PdCl2 or the longer addition time be a factor? Better Methanol? Keeping temp under 70 C.? I also did 2 distilled H2O washes of the DCM AFTER the final NaOH wash.
Any ideas?