Piperidinone carboxamide spirohydantoin cgrp receptor antagonists

A compound of Formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• R1 is selected from the group consisting of:
• C1-4alkyl, cyclopropylmethyl, cyclobutylmethyl and [1-(trifluoromethyl)cyclopropyl]methyl, each of which is optionally substituted with one to four substituents as allowed by valence independently selected from the group consisting of hydroxyl and F;
• R2 is hydrogen or methyl;
• when R2 is hydrogen then
• R3 is selected from hydrogen, F or Cl;
• R4 is selected from hydrogen, F or Cl;
• R5 is hydrogen;
• R6 is selected from hydrogen or F;
• and
• R7 is selected from hydrogen, F or Cl;
• except that at least two of R3, R4, R6 and R7 must be F or Cl, unless R3 is F in which case R4, R6 and R7 may all be hydrogen;
• and if R4 is Cl then R7 cannot be Cl;
• when R2 is methyl then
• R3 is selected from hydrogen, methyl, F, Cl, or Br;
• R4 is selected from hydrogen, methyl, F or Cl;
• R5 is selected from hydrogen or F;
• R6 is selected from hydrogen or F;
• and
• R7 is selected from hydrogen, methyl, F or Cl;
• except that if R5 is F then at least three of R3, R4, R6 and R7 must be F;
• and if R4 is methyl or Cl then R7 cannot be methyl or Cl;
• and
• R8 is selected from the group consisting of:
• hydrogen, C1-4cyclopropylmethyl, and cyclobutylmethyl, each of which is optionally substituted with one to three fluoro substituents as allowed by valence.