Diisopropylethylamine → tert-butyl (S)-3-(3-(4-(5-bromopyrimidin-2-yl)phenyl)-2-(4-(tert-butyl)benzamido)propanamido)propanoate

Participants

Reaction Steps

Prepared using General Procedure 7. A stirring solution of β-alanine tert-butyl ester hydrochloride (4.9 g, 27.4 mmol), (S)-3-(4-(5-bromopyrimidin-2-yl)phenyl)-2-(4-(tert-butyl)benzamido)propanoic acid (12.0 g, 24.9 mmol) and DIEA (11.1 mL, 62.0 mmol) in DMF (200 mL) was cooled to 0° C. A solution of HATU (9.9 g, 26.1 mmol) in DMF (75 mL) was added dropwise over 20 min. The reaction mixture was allowed to warm to room temperature over 2 h, then diluted with EA and washed with NaHCO3 (sat aq). The aqueous fraction was back-extracted with EA. The combined organic fractions were dried (Na2SO4) then concentrated onto celite and purified by column chromatography (EA/hexane) to provide 11 g (65%) of tert-butyl (S)-3-(3-(4-(5-bromopyrimidin-2-yl)phenyl)-2-(4-(tert-butyl)benzamido)propanamido)propanoate INT-28. LCMS-ESI (m/z) calculated for C31H37BrN4O4; 609.6. found 610.2 [M+H]+, tR=3.99 min (Method 15), and 87.1% e.e. (Chiral Method, isocratic with 20% Solvent A, 80% Solvent B). 1H NMR (400 MHz, CDCl3) δ8.80 (s, 2H), 8.32 (t, J=6.5 Hz, 2H), 7.74-7.62 (m, 2H), 7.41 (d, J=8.5 Hz, 2H), 7.35 (t, J=7.9 Hz, 2H), 6.91 (d, J=7.7 Hz, 1H), 6.53 (t, J=5.9 Hz, 1H), 4.93-4.81 (m, 1H), 3.52-3.34 (m, 2H), 3.34-3.14 (m, 2H), 2.46-2.24 (m, 2H), 1.34 (d, J=5.2 Hz, 9H), 1.31 (d, J=5.2 Hz, 9H).

Provenance & Evidence