Synthesis of Haloperidol with 4-chlorobutanoyl chloride and piperidin-4-one

I searched for a easy synthesis on Haloperidol.


[![enter image description here](https://i.stack.imgur.com/u5UVd.png)](https://i.stack.imgur.com/u5UVd.png)


Step 1 and 2 are taken from <https://www.slideshare.net/SagarJoshi2/antipsychotics-33785528> (Slide 23). I just tried to work out a way to prepare 4-(4-chlorophenyl)piperidin-4-ol via Grignard.


Does the 4-chloro group has any negative influence on the reaction.




The reaction mechanism for the step in question simply involves initial formation of a Grignard reagent followed by nucleophilic attack into the ketone. 


[![enter image description here](https://i.stack.imgur.com/m0jzW.png)](https://i.stack.imgur.com/m0jzW.png)


When forming Grignard reagents from halides, there is a general trend that the rates of formation are in the order I > Br >> Cl, making it possible to get selectivity where multiple halides exist. 


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