Burn the place down
Your anger is further than your reason and all you want to do is destroy this abomination of a place. You look around for fuel and find a pile of bloodstained aprons lying in the corner. That should do the trick. Though the real trick is starting multiple fires, making sure that even he manages to extinguish one the others will do him in all the same. You don’t know much of chemistry but you do know that bottles carrying red bands around the neck have flammable things inside them and so you take to collecting a couple. You unscrew the bottle of one and dump it all over the pile of rags, then light it with your lighter. You then run to your next target. A bookcase full of old dry books practically begging to be kindle. You grab some volumes and strew them over the floor, ready to ignite, some chemicals and a lighter later and only now the alchemist starts to notice but because you made sure that the fires were far away from one another they don’t have the time to deal with you as he runs to his precious books hoping to save them. You light the velvet curtain on my way out. You open the bookcase and rush to the exit, then make sure to keep running till you know you are safe.