Triethylamine → (S)-tert-butyl 3-(6-(difluoromethoxy)pyridin-3-yl)-3-(1-(2,2-dimethoxyethyl)-3-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propyl)ureido)propanoate

Participants

Reaction Steps

To a stirred solution of compound 8 (375 mg, 0.99 mmol, 1.0 equiv.) in dry DCM (5 mL), cooled to 0° C., triphosgene (1.50 mL, 2.99 mmol, 3.00 equiv., 20% in PhMe) followed by Et3N (0.30 mL, 2.09 mmol, 2.10 equiv) were added. The reaction mixture was slowly brought to RT and stirred for 2 h. After completion of the starting material, volatiles were evaporated to afford the crude compound 9, which was used directly in the next step without purification. A solution of compound 9 in DCE (2 mL) was added to a solution of compound 6b (400 mg, 1.32 mmol, 1.32 equiv.) in DCM (5 mL), Et3N (0.55 mL, 3.98 mmol, 4.00 equiv) at 0° C. and stirred at RT for 4 h. After consumption of the starting material (monitored by TLC), the reaction mixture was concentrated under reduced pressure to give the crude residue which was purified by column chromatography (2% MeOH/DCM) to afford compound 10 (0.40 g, 67%) as a thick syrup.

Provenance & Evidence