Cyclohexane has a boiling point of 81 °C what would mean the thermal rearrangement would need 7 to 10 days at reflux. But then one could use IPA, same bp and it is known to work from literature (7 to 10 days at reflux).
Ethylbenzoate works.
Ethylene Glycol is another solvent which works and of better availability.
The yield is never near to quantitative, actually when using the Ketimine as base yields suffer, for decent yields the HCl salt must be used. It must also be done under strictly anhydrous conditions or yields suck. (the Imine will hydrolyze back to MeNH2, unsurprisingly regarding the rigorous conditions).
The rearrangement is catalyzed by Lewis Acids, MgCl2 And AlCl3 (anhydrous) work well. 0,1 mol equivalent are needed but AlCl3 can also take care of any water still present, the amount used must be adjusted of course, say X g needed to scavenge the water plus 0,1 mol to catalyze the reaction.
The use of AlCl3 reduces the temperature needed to ~130 °C (to take the same time as 180 °C would take un-catalyzed).
Another tip: Stay away from CCl4 the stuff is not just toxic but its mean and hard to get for good reasons. Gladly it is completely unnecessary for brominating the alpha position. The foolproof way to do this is by using CuBr2 what does the job quantitativly and without side-reactions.
For reaction conditions just Google "Bromination with CuBr2" and you will quickly find the standard conditions for this described and those work perfectly well in this case.