(The following reaction is done in an anhydrous N2 atmosphere.) Suspend EDC hydrochloride (402 mg, 2.10 mmol) and Et3N (293 μL, 2.10 mmol) in anhydrous dichloromethane (17.0 mL) and stir the resulting solution for 5 min at rt. Add 3-(3,4,5-trimethoxy-phenyl)-propionic acid (481 mg, 2.00 mmol) and DMAP (24 mg, 0.20 mmol) and stir the resulting solution for 5 min. Add 3-nitro-phenylamine (90) (414 mg, 3.00 mmol) and stir the reaction solution 24 h at rt. Quench reaction solution with sat. aqu. NH2Cl and water, separate layers and extract aqu. layer with EtOAc (3 times). Wash the combined organic layer with water and brine and dry with Na2SO4. Purify the crude product by preparative radial chromatography (silica gel 60PF, EtOAc/CyH 1+1) to obtain N-(3-nitro-phenyl)-3-(3,4,5-trimethoxy-phenyl)-propionamide (91) (508 mg, 70%) as a yellowish solid. 1H NMR (400 MHz, CDCl3): 2.65 (t, 2H, J=7.3 Hz); 2.98 (t, 2H, J=7.3 Hz); 3.79 (s, 6H); 3.81 (s, 3H), 6.42 (s, 2H); 7.41 (s, 1H); 7.45 (t, 1H, J=8.0 Hz); 7.84 (d, 1H, J=8.0 Hz); 7.92 (d, 1H, J=8.01 Hz); 8.31 (s, 1H).
