Diphosgene → tert-Butyl 4-(2-(4-(3-(3-tert-butyl-1-p-tolyl-1H-pyrazol-5-yl)ureido)naphthalen-1-yloxy)-2-methylpropyl)pyridin-2-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-tert-butyl-1-p-tolyl-1H-pyrazol-5-amine (4) (WO 2000043384) (250 mg, 1.090 mmol) in DCM (25 mL) was added a saturated solution of aq NaHCO3 (17 mL), and the mixture was stirred vigorously. The mixture was cooled to 0° C. and then trichloromethylchloroformate (395 μl, 3.27 mmol) was added in one portion. The resulting mixture was stirred at 0° C. for 90 min. The layers were then separated, the organic extract was dried and the solvents removed under reduced pressure to afford a brown-orange oil, which was dried under high vacuum, at 30° C. for 30 min. The resulting oil was then taken up in THF (4.0 mL), and was added to tert-butyl 4-(2-(4-aminonaphthalen-1-yloxy)-2-methylpropyl)pyridin-2-ylcarbamate (28) (92 mg, 0.23 mmol). DIPEA (118 μl, 0.677 mmol) was then added, and the reaction mixture was stirred at RT over 17 hr. Water (15 mL) and EtOAc (15 mL) were added to the purple mixture and the layers separated. The aqueous layer was extracted with EtOAc (10 mL). The combined organic extracts were washed with brine (20 mL), dried and the solvents removed under reduced pressure. The crude material was purified by column chromatography (40 g) eluting with 0 to 50% EtOAc in iso-hexane, to give tert-butyl 4-(2-(4-(3-(3-tert-butyl-1-p-tolyl-1H-pyrazol-5-yl)ureido)naphthalen-1-yloxy)-2-methylpropyl)pyridin-2-ylcarbamate (29) (24 mg, 14%) as a purple foam: m/z 663 (M+H)+ (ES+).

Provenance & Evidence