[Angobango]

The questions I have center around Haloperidol http://en.wikipedia.org/wiki/Haloperidol and how it compares with Meperidine http://en.wikipedia.org/wiki/Meperidine

1) What effect would substitution of the N-methyl group with the butyrophenone group have on the compounds distribution and elimination?

I have searched and searched for info on this one but everything I find is rather lacking.

2) The propyl chain in haloperidol was found to be optimal for activity. What effect could chain elongation have on both the pharmacokinetics and pharmacodynamics of the molecule?

Again, most of the info I've found only manages to go so far as to say that the chain length IS optimal rather than what makes it optimal

3) Suggest roles for the flourine and chlorine substitution in haloperidol

I have some idea of what this one is about. I know that the chlorine increases lipid solubility and that flourine draws electrons. I'm thinking that these substitutions allows for the molecule to breach the blood-brain barrier and have a neurological effect?

I know it seems like a fair bit of stuff but I really have spent all evening looking through my textbooks, lecture notes and online for any info that might help me answer these. I'm not expecting they'll all get completely answered here but any help would be very much appreciated.

Thank you for your time.