Cesium carbonate → (S)-1-(2-methoxy-1-phenylethyl)-3-(3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridin-6-yl)urea

Participants

Reaction Conditions

Reaction Steps

6-Chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridine (Example 40, Step 1; 151 mg, 0.355 mmol), (S)-1-(2-methoxy-1-phenylethyl)urea (Intermediate 16B; 108 mg, 0.556 mmol), BrettPhos pre-catalyst (17.6 mg, 0.022 mmol), and cesium carbonate (337 mg, 1.034 mmol) were taken up in 1,4-dioxane (3.5 mL) in a 5 mL microwave vial. The vial was evacuated and back-filled with N2 (×3) and the reaction stirred at 100° C. for 6 h. Room temperature was attained, the reaction mixture was filtered through Celite, eluting with MeOH, and the filtrate was concentrated in vacuo. Purification of the residue by flash chromatography (6-50% EtOAc-hexanes) gave (S)-1-(2-methoxy-1-phenylethyl)-3-(3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridin-6-yl)urea. MS ESI calc'd. For C36H33N5O3 [M+1]+ 584. found 584.

Provenance & Evidence