Diisopropylethylamine → tert-butyl methyl((S)-1-((2S,3S)-2-methyl-4-oxo-1-(tetrahydro-2H-pyran-4-carbonyl)-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylamino)-1-oxopropan-2-yl)carbamate

Participants

Reaction Steps

To a room temperature solution of (3S,4S)-3-amino-4-methyl-5-(tetrahydro-2H-pyran-4-carbonyl)-4,5-dihydro-1H-benzo[b][1,4]diazepin-2(3H)-one hydrochloride (173 mg, 509 μmol) in N,N-dimethylformamide (2 ml) was added Boc-N-methyl-L-alanine (114 mg, 560 μmol), N,N-diisopropylethylamine (440 μl, 2.55 mmol), and HBTU (212 mg, 560 μmol). The reaction was stirred at room temperature for 2 h. After this time, the reaction was diluted with ethyl acetate (20 mL), washed with a saturated aqueous sodium bicarbonate solution (20 mL) and the aqueous layer was then extracted with ethyl acetate (3×10 mL) and the combined organics were washed with a saturated aqueous sodium chloride solution (20 mL), dried over sodium sulfate, filtered, and the filterate concentrated in vacuo. The crude material was purified using an Initelliflash 280 system (4 g silica gel column Varian brand, 20-90% ethyl acetatehexanes) to afford tert-butyl methyl((S)-1-((2S,3S)-2-methyl-4-oxo-1-(tetrahydro-2H-pyran-4-carbonyl)-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylamino)-1-oxopropan-2-yl)carbamate (238 mg, 96%): LC-MS m/z 487 [M−H]−.

Provenance & Evidence