Triethylamine → tert-butyl (2S)-2-[(1R,2R)-3-{[2-(cyclohepta-2,4,6-trien-1-yl)ethyl]amino}-1-methoxy-2-methyl-3-oxopropyl]pyrrolidine-1-carboxylate

Participants

Reaction Steps

To a solution of #11 (3.57 g, 12.4 mmol, 1 eq.) in dichloromethane (100 mL, 0.1 M) and N,N-dimethylformamide (4 mL) was added HATU (5.36 g, 13.7 mmol, 1.1 eq.). After 20 minutes, triethylamine (5.20 mL, 37.3 mmol, 3 eq.) was added, followed by #62 (1.68 g, 12.4 mmol, 1 eq.), and the mixture was stirred for 18 hours. The reaction was concentrated in vacuo and the residue was taken up in ethyl acetate and washed with water (50 mL). The aqueous layer was back-extracted with ethyl acetate (3 times) and the combined organic layers were dried, filtered, and concentrated in vacuo to provide a brown oil, which was purified by silica gel chromatography (Gradient: 0% to 100% ethyl acetate in heptane) to provide #63 (2.95 g, 59% yield) as a viscous oil. LC-MS: m/z 405.4 [M+H+], 427.4 [M+Na+], retention time=0.75 minutes; 1H NMR (400 MHz, CDCl3), presumed to be a mixture of rotamers: δ 6.63-6.68 (m, 2H), 6.16-6.23 (m, 2H), 5.19 (br dd, J=9.0, 5.8 Hz, 2H), 3.51-3.63 and 3.71-3.90 (2 br multiplets, total 3H), 3.42 (s, 3H), 3.18-3.29 and 3.34-3.47 (2 br multiplets, total 3H), 2.27-2.45 (br m, 1H), 1.6-2.00 (m, 7H), 1.47 and 1.50 (2 br s, total 9H), 1.16-1.29 (br m, 3H).

Provenance & Evidence