Diisopropylethylamine → (S)-ethyl 1-((S)-2-(tert-butoxycarbonylamino)-2-(tetrahydro-2H-pyran-4-yl)acetyl)-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine-2-carboxylate

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Reaction Steps

In a 100 mL round-bottomed flask, (S)-2-(tert-butoxycarbonylamino)-2-(tetrahydro-2H-pyran-4-yl)acetic acid (270 mg, 1.04 mmol, Eq: 1.00) was combined with DCM (10 mL) to give a colorless solution. Diisopropylethylamine (0.73 mL, 4.16 mmol, Eq: 4) was added followed by N,N,N′,N′-tetramethylfluoroformamidinium hexafluorophosphate (824 mg, 3.12 mmol, Eq: 3). The reaction was stirred at rt for 1 h and then (S)-ethyl 2,3-dihydro-1H-pyrrolo[2,3-b]pyridine-2-carboxylate (200 mg, 1.04 mmol, Eq: 1.00) was added. After stirring overnight at rt, the reaction mixture was washed with saturated aqueous NaHCO3 (50 mL), dried over Na2SO4 and concentrated in vacuo. The crude material was purified by flash chromatography (silica gel, 24 g, 0% to 30% EtOAc in hexanes) to give (S)-ethyl 1-((S)-2-(tert-butoxycarbonylamino)-2-(tetrahydro-2H-pyran-4-yl)acetyl)-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine-2-carboxylate (220 mg), m/z=434 (M+H).

Provenance & Evidence