Synthesis of three isotopically labeled versions and a metabolite of Aurora A kinase inhibitor

Sodium ring-[14C]-4-[[9-chloro-7-(2,6-difluorophenyl)-5H-pyrimido[5,4-d][2]benzazepin-2-yl]amino]-benzoate (1A, MLN8054), an Aurora A kinase inhibitor, was synthesized from [14C]-cyanamide in two steps in an overall radiochemical yield of 7%. The intermediate, [14C]-4-guanidinobenzoic acid, was prepared by coupling [14C]-cyanamide with 4-aminobenzoic acid. Sodium carboxyl-[14C]-4-[[9-chloro-7-(2,6-difluorophenyl)-5H-pyrimido[5,4-d][2]benzazepin-2-yl]amino]-benzoate (1B) was synthesized from carboxyl-[14C]-4-guanidinobenzoic acid in one step in a radiochemical yield of 35%. [D4,15N]-4-[[9-chloro-7-(2,6-difluorophenyl)-5H-pyrimido[5,4-d][2]benzazepin-2-yl]amino]-benzoic acid (1C) was synthesized from [15N2]-cyanamide and [D4]-4-aminobenzoic acid in two steps in an overall yield of 37%. The major metabolite, β-acyl glucuronide of 4-[[9-chloro-7-(2,6-difluorophenyl)-5H-pyrimido[5,4-d][2]benzazepin-2-yl]amino]-benzoic acid (14), was synthesized from D-glucuronic acid in three steps in an overall yield of 1%. The key intermediate for synthesis of glucuronide was prepared by HATU catalyzed coupling of 4-[[9-chloro-7-(2,6-difluorophenyl)-5H-pyrimido[5,4-d][2]benzazepin-2-yl]amino]-benzoic acid with allyl glucuronate. Copyright © 2009 John Wiley & Sons, Ltd.