Ideally, extinguish the flames with a glass watch or beaker.
Explanation:
When you cover the distillation equipment with a watch glass or beaker, you reduce the oxygen content and it is completely eliminated thanks to the fire itself that consumes it. Once there is no more oxygen the fire is extinguished and it should take no more than 2 or 3 seconds to occur this situation
It is the easiest and most careful way to extinguish the fire during the Grignard reaction
