reimer tiemann reaction mechanism

step 1 : phenol react with  NaOH +CHcl3 . then release' h' of phenol and OH of sodium hydra oxide .

and then result is benzine +ONa 

step 2 :then react with CHcl3 .  and then result is benzine +ONa +chcl2

step 3 : final react with 2NaOH  .and then result is phenoxide.