Challenger 300 Captain reported the failure of the Air Conditioning and Pressurization Pack system during cruise. The flight crew diverted to an appropriate airport safely.

Narrative

At approx XA10 at FL450 we got a Cyan Bleed Loop Fail CAS (Crew Alerting System). Upon checking the current faults page we saw PACK DUCT AIR LEAK which was not associated with any CAS. We completed the Cyan Bleed Loop Fail checklist; and I sent the information to the Chief Pilot and Maintenance Control. A few minutes later we got a Master Warning and red PACK LEAK CAS. We completed the initial actions on the checklist. We advised ATC and initiated an emergency decent after verifying everyone was belted. Our initial clearance was to FL150. The temp in the IP air was still in excess of the high temp limits. We had an Air Cond Temp High caution and hot plastic smell in the cabin. Passing FL380 I selected MAN TEMP and max cold. The temperature of the air in the lines was hot but within limits. The Trim air then turned from amber to green. Per the Pack Leak checklist we could then sustain a maximum altitude of FL350. We used that opportunity to collect ourselves and verify the abnormal checklists. Then we diverted to ZZZ. Passing below 9000MSL we selected air source off and Emer depress per the approach section of the abnormal check list.No reports were requested by ZZZ Center.Cause: Failure of the PACK system.Suggestions: This was an unforeseen equipment failure. Training was followed.