Dicyclohexylcarbodiimide → N,N'-Dicyclohexylurea

Participants

Reaction Steps

DCC (0.56 g, 2.7 mmol) in CH2Cl2 (20 mL) was added dropwise to a stirred solution of the product of Example 13d (0.5 g, 2.45 mmol), (2S)-2-(6-methoxy(2-naphthyl))propanoic acid (0.56 g, 2.45 mmol), and DMAP (0.05 g) in CH2C2 (20 mL) at room temperature. The resulting suspension was stirred for 1 hour at room temperature. The precipitate was removed by filtration and washed with CH2Cl2 (25 mL). The filtrate was concentrated to give a green oil which was chromatographed on silica gel eluting with 1:9 MeOH:CH2Cl2 to afford a green solid (contaminated with dicyclohexyl urea). The solid was triturated with hexane (50 mL) and filtered. The filtrate was concentrated to give the title compound (0.7 g, 69%) as a viscous green oil. 1H NMR (300 MHz, CDCl3) δ 7.50-7.65 (mult, 3H), 7.01-7.29 (mult, 3H), 4.18 (t, J=6.5 Hz, 2H), 3.83 (s, 3H), 3.72 (q, J=7.0 Hz, 1H), 2.51 (t, J=6.6 Hz, 2H), 2.13 (s, 3H), 2.00-2.60 (mult, 8H), 1.45 (d, J=7.2 Hz, 3H), 1.47 (d, J=7.1 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 174.4, 157.7, 135.4, 133.7, 129.2, 128.9, 127.2, 126.1, 126.0, 119.0, 105.6, 61.1, 57.6, 55.3, 51.4, 51.3, 46.0, 45.4, 40.8, 36.5, 36.4, 18.2; mass spectrum (API-TIS) m/z 415 (M+H).

Provenance & Evidence