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9th August 2012 @ 05:43
Repeat of MNR41-15 but leaving out the PZQ.

MNR41-4%20scheme.png
mnr41-16%20table.PNG

To a solution of MNR42-1 (0.1 g, 0.32 mmol) in HPLC grade acetonitrile (10 mL) and under argon at 0 °C, was added was added acetyl chloride (0.041 mL, 0.57 mmol), 2,6-lutidine (0.052 mL, 0.48 mmol, fresh out of a new bottle). The reaction was then shaken at room temperature (19 °C) for 1 hour.

After 75 minutes a sample was taken for mini workup and LCMS. The reaction was left to shake.

After 1 hour a sample was taken for mini workup and LCMS. The reaction was left to stir for another hour and then worked up.

Work Up

The mixture was filtered to remove the molecular sieves and washed with EtOAc (20 mL). The filtrate was washed with saturated sodium bicarbonate solution (25 mL). The aqueous layer was extracted with ethyl acetate (3 × 30 mL). The organic fractions were combined, dried over MgSO4, filtered and concentrated under reduced pressure to yield a yellow solid (0.127 g)

It was then attempted to take the crude up in IPA (3 ml) but it would not go into solution - possibly starting material??

The majority of the IPA was decanted off via pipette and transferred to a vial to see if anything would crystallise overnight. Washed with IPA in the morning

crystals from the decanted solvent - 0.56 g
crystals from the remaining solvent - 0.28 g

LCMS

mnr41-16_90mins.pdf


NMR

mnr41-16_decanted.pdf


mnr41-16_flask.pdf


Both samples showed clean product.

Conclusion

Total recovered after 1 recrystallisation - 0.084 g, 0.236 mmol, 74%.

Product forming after 90 minutes, the reaction is therefore not affected by the ytterbium, molecular sieves or the PZQ.
Attached Files
mnr41-16 table.PNG
mnr41-16_90mins.pdf
mnr41-16_decanted.pdf
mnr41-16_flask.pdf