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2nd January 2018 @ 14:46

Step 3.jpg

Masses and measurements:

3,4-difluorophenyl acetic acid - 0.9934g

LiAlH4 - 0.2386g

THF - 6.3mL

Procedure:

The 3,4-difluorophenyl acetic acid (0.9934g, 5.78mmol) was added to a RBF and was dissolved in THF (6.3mL). The reaction mixture was further stirred whilst the LiAlH4 (0.2386g, 6.29mmol) was added and the reaction mixture was stirred under reflux for 2-3 hours or until TLC analysis (1:1 ethyl acetate & petroleum ether) confirmed the completion of the reaction. Around 20mins after all reagents were added, the mixture turned a deep red and soon after turned to a pale yellow solution.

reaction of alcohol.jpg
                                          
alcohol synthesis.jpg

Once the reaction was complete, the reaction mixture was left to cooland quenched with 25% NaOH (10mL) and the product was seperated and extracted using 2M HCl (20mL) and ethyl acetate (20mL). Seperation of the reaction mixture gave 2 colourless solution layers. The aqueous layers were re-extracted using diethyl ether (20mL) - it was learnt in the research we underook that the alcohol product is very volatile so diethyl ether was used as it has a lower volatilty to match that of the final product. The organic layers were collected, dried using MgSO4 and filtered under vacuo. The filtrate was rotary evporated with a small amount of solvent present still. The product given was a pale yellow oily solution (0.729g, 79.85%).

Attached Files
Step 3.jpg
reaction of alcohol.jpg
alcohol synthesis.jpg