Di-tert-butyl dicarbonate → HCID 69371147, compound

Participants

Reaction Conditions

Reaction Steps

(3S)-1-[(2S,3S)-2-(tert-Butoxycarbonylamino)-3-[4-(6-methoxypyridin-3-yl)phenyl]-1-oxobutanyl]-3-fluoropyrrolidine from Example 5, Step A (0.65 g, 1.42 mmol) was mixed with pyridine hydrochloride (2.25 g, 19.5 mmol) neat and placed in a preheated oil bath (160° C.). After stirring at 160° C. for 20 min, the reaction was cooled to room temperature and neutralized to pH 7 with saturated sodium bicarbonate solution. To this was added 15 mL of 1,4-dioxane followed by di-tert-butyldicarbonate (2.14 g, 9.82 mmol). After stirring at room temperature for 12 h, the reaction was partitioned between ethyl acetate and saturated aqueous brine. The organic layer was separated, and the aqueous layer was extracted with two portions of ethyl acetate. The combined organic layers were dried over sodium sulfate and the solvents removed by evaporation under diminished pressure. Purification by preparative TLC (silica, 50% ethyl acetate/hexanes) afforded the desired product.

Provenance & Evidence