Diisopropylethylamine → HCID 67606455, compound

Participants

Reaction Conditions

Reaction Steps

A solution containing crude 54 (˜3.8 g, 17.9 mmol) and DIPEA (4.1 mL, 23.3 mmol) in NMP (50 mL) was cooled to 0° C. In a separate flask, Cbz-Tle-OH dicyclohexylamine salt (8.8 g, 19.7 mmol), HATU (7.5 g, 19.7 mmol), and DIPEA (4.1 mL, 23.3 mmol) were dissolved in NMP (130 mL) at 0° C. A portion of the HATU/Cbz-Tle-OH solution (117 mL, ˜1.0 equiv) was added to the solution containing 54. After 30 min, the reaction mixture was diluted with water and extracted with 1:1 Et2O/EtOAc. The combined organic extracts were washed successively with 10% H3PO4, water, saturated aqueous NaHCO3, water, and brine, dried over anhydrous Na2SO4, filtered, and concentrated to afford 7.2 g of 55 as a beige-colored foam (88%, 4 steps) which was used without further purification. Mass spectrum, m/z [460.9] (M+H)+.

Provenance & Evidence