So, making a 4-MAR halogen analog would be -pharmacologically speaking - a shot in the dark.
I got inspired by this:
"Contrary to previously cited work this suggests that aminorex may in fact be as potent an adrenomimetic as amphetamine. In any case, Poos (personal communication) highlighted eight compounds which may have adrenomimetic activity similar to those of amphetamine and methamphetamine.
Shown below and listed in decreasing order of anoretic activity they are:
1) 2-amino-5-(4-fluorophenyl)-2-oxazoline
2) 2-amino-5-(4-Chlorophenyl)-2-oxazoline
3) 2-amino-5-(3-trifluoromethylphenyl)-2-oxazoline
4) 2-amino-5-(4-bromophenyl)-2-oxazoline
5) 2-amino-5-phenyl)-2-oxazoline [aminorex]
6) 2-amino-5-(4-trifluoromethylphenyl)-2-oxazoline
7) 2-dimethylamino-4-methyl)-5-phenyl-2-oxazoline
2-amino-4-methyl-5-phenyl-2-oxazoline [4-methylaminorex].
Although not mentioned in this work, one would immediately assume that the 4-fluoro- and 4-chloro-phenyl derivatives of compounds 7 and 8 would also have significant anoretic activity. Given the astoundingly simple synthetic process required to produce these compounds, and the fact that the 4-halogen substituted aryl derivatives would require precursors unlikely to titillate the interest of law enforcement agencies, these compounds will most probably be made in future clandestine syntheses. It is also conceivable that some enterprising clandestine chemist will wonder if appropriately substituted methoxy derivatives will have psychotomimetic properties. "
From:
https://www.thevespiary.org/rhodium/Rhodium/chemistry/future_drugs.html