No. It will actually make your room hotter still.
Here is a technology briefer on portable A/Cs.
The deal-killer is that "one hose" thing. In your case, you're going to get it coming and going. You can only make this work if both the A/C and your passage are "two-hose".
Here's why that won't work as-is.
In the room with the one-hose A/C unit, the unit is ejecting hot air outside, via the one hose. That's how those units work. That air is being replaced by air being sucked in from anywhere possible - window leaks, door cracks, etc. And the air coming in is hot, wet outside air -- which defeats the purpose of air conditioning.
But it'll be worse with your setup. This vacuum on the A/C room will also draw air from your room. That will be replaced with hot, wet air from outside! In your room!
It's not just the heat. It's the humidity.
The biggest problem with "sucking hot/wet air from outside" is the wet. Humidity is just as important as temperature to your feeling of heat.
Now, stop and research the latent heat of vaporization. Removing humidity from air requires air conditioning - but all this air conditioning is poured into the latent heat of vaporization - turning water vapor into liquid water. This doesn't even cool the air (but it makes the air feel cooler because of lower humidity).
The upshot is that WET air coming in from outside is BAD NEWS. You need to minimize the amount of air being sucked in from outside, because you have to dehumidify it and that would steal a lot of your A/C capacity.
Two hoses - both places
The A/C unit makes some air hot, as you know. The air that it makes hot doesn't need to be air conditioned. Wet, hot outside air will work just fine for that. That's why two-hose portable air conditioners work just fine.
You need a 2-hose portable A/C (or hack your unit into being 2-hose) because if you use 1-hose, it'll suck hot wet air into your room, and that will defeat the entire purpose.
But also, when you pump air from the A/C room to your room, you need a 2-hose passage there too. You don't want conditioned air being pushed out of your room to ??? (because that's a waste) and then other air being sucked from ??? into the A/C room because that is likely to be more of that hot, wet air we don't want.
So that's it. Think 2-hose and it'll work. Take the default 1-hose and this won't work well enough to even bother.