Patent ID: 8742099

Claim:
A process for the preparation of compounds of formula (I): or a pharmaceutically acceptable salt thereof wherein: R 1 is 2-indanyl, R 2 is 1-methylpropyl, R 3 is a group selected from 2,6-dimethyl-3-pyridyl and 4,6-dimethyl-3-pyridyl, and R 4 and R 5 together with the nitrogen atom to which they are attached represent morpholino; where the method comprises the steps of: (a) reacting a compound of formula (III) wherein R 6 is 2-hydroxyphenyl, with 1,1′-carbonyldiimidazole or 1,1′-thiocarbonyldiimidazole in a suitable solvent; and (b) reacting the product formed in step (a) with the amine HNR 4 R 5 .