KBS14-6 - Methyl esterification of ferrocenecarboxylic acid

[KlementineJBS]

Link to HIRAC and master page. Method developed from Julius Adamson.

Ferrocenyl methyl ester synthesis .docx

Reaction Scheme

Outcome

715 mg (2.93 mmol), 67%

Notes

Further extractions would likely improve yield, but are time consuming. Consider alternative method here for next time.

[KlementineJBS]

17.03.22

• cooled 10 mL methanol in ice
• added acetyl chloride (0.4 mL, 5.61 mmol)
• left stirring on ice for 15 mins
• added ferrocencarboxylic acid (1.0031 g, 4.36 mmol)
• warmed to room temperature and began refluxing at 12.30 (heating mantle, condenser, under nitrogen due to humidity)
• turned off after 1 hour of reflux and left to cool
• TLC indicated reaction was not complete

[KlementineJBS]

18.03.22

• heated to reflux again at 10am
• took off at 11am as TLC indicated signs of decomposition (third product appeared below SM spot). Reaction mixture also appeared grainy and darker in colour, as compared to the reddish colour prior to second reflux
• left to crystallise

[KlementineJBS]

23.03.22

• no crystallisation after being left in fridge for multiple days
• quenched with NaHCO3 (50 mL) and NaOH (10 mL) until basic (pH ~ 11)
• rotvapped all methanol off -- runoff was bright yellow and does seem to contain product or an impurity with similar Rf value
• transferred to separating funnel with brine (150 mL) and water (50 mL)
• added 125 mL EtOAc
• separated
• extracted with another 100 mL of EtOAc and left to separate overnight

[KlementineJBS]

24.03.22

• 3rd extraction with 100 mL EtOAc
• lots of emulsification -- tried to decant organic layer when pouring off to leave dark brown solid in sep funnel
• 4th extraction with EtOAc (100 mL)
• dried over MgSO4

After addition of MgSo4

[KlementineJBS]

29.03.22

• filtered and rotovapped
• vial = 16.0381 g
• vial (product) = 16.7529 g
• product = 0.7148 g

[KlementineJBS]

NMR

1H NMR (300 MHz, Chloroform-d) δ 4.80 (t, J = 2.0 Hz, 2H), 4.39 (t, J = 2.0 Hz, 2H), 4.20 (s, 5H), 3.81 (s, 3H).

KBS14-6 processed.pdf

KBS14-6_1 (1).zip