Disclosed are compounds of the formula (I) and pharmaceutically acceptable salts thereof: (I) wherein R1, R2, R3, R4, R5, R6, R8, R9, X, X1, X2, X3, L1 and n are as defined herein. The compounds are inhibitors of adrenomedullin receptor subtype 2 (AM2). Also disclosed are the compounds for use in the treatment of diseases modulated AM2, including proliferative diseases such as cancer; pharmaceutical compositions comprising the compounds; methods for preparing the compounds;and intermediates useful in the preparation of the compounds.