[dennisinned]

Hi,

In my lab last week, we were tasked to synthesize Grignard reagent with the use of aryl bromide. However, some student made use of excess Mg while the others made use of excess aryl bromide. I have asked my prof and he simply said to use excess Mg without much explanation. What is the reason for using excess Mg? Will there be side reaction for using excess aryl bromide?

Thanks and have a nice day!

[Borek]

Will there be side reaction for using excess aryl bromide?

Try to follow this line of thinking.

[dennisinned]

Thanks for replying!
I have thought about SN2 reaction but it doesn't seem possible with Aryl Bromide. Is it possible that aryl bromide in presence of strong base like Grignard, forms benzyne?

Thank you.