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).
