The title compound 6-(1-(benzo[d]thiazol-2-ylcarbamoyl)-1,2,3,4-tetrahydroquinolin-7-yl)-3-phenylpicolinic acid (29) was prepared by the following procedure: To methyl 6-(1-(benzo[d]thiazol-2-ylcarbamoyl)-1,2,3,4-tetrahydroquinolin-7-yl)-3-phenylpicolinate (29I) (23 mg, 0.044 mmol) in MeOH (0.55 mL) and water (0.11 mL) was added an aqueous solution of LiOH (0.066 mL of 2.0 M, 0.13 mmol). The reaction mixture was stirred at rt for 15 hours, concentrated under reduced pressure to remove MeOH and diluted with water. The pH was adjusted to ˜4 with 2 M HCl, and the resulting precipitate was isolated by filtration and washed with water. The crude material was purified by column chromatography on silica gel eluting with a gradient of DCM:MeOH 98:2-92:8, to provide the desired product 6-(1-(benzo[d]thiazol-2-ylcarbamoyl)-1,2,3,4-tetrahydroquinolin-7-yl)-3-phenylpicolinic acid (29): MS (ESI(+)): m/z 507.1 (M+H).
