Probably neurotoxic. Just look at 6-OH dopamine. -OH and -Cl groups are generally bioisosteric in terms of how they are recognized by proteins (but obviously differ in polarity)
A chloro substituent should raise lipophilicity IMO and, therefore, BBB-penetrability. So, if this stuff is neurotoxic (and I second wungchow here), it should be even worse 6-OH-dopamine.
Unfortunately, displacement of the methylene bridge, leaving the 3,4-dihydroxy derivative is a reported metabolism pathway. This even strengthens the proposed toxicity.
Remember 6-methyl-MDA is inactive, so the 6-spot may not be very tolerant to bulk. On the other hand MMDA-2 with a 6-methoxy group is active, and its N-methyl derivative too.
I would also be concerned about the toxicity of 6-chloro or 6-nitro MDMA or MDA. Why the 6-position anyway? The 5-position is more likely to be the sweet spot I'd say, 5-methyl-MDA is significantly more potent than MDA itself according to Nichols paper on it.