4-iodo-2-methyl-6-nitrobenzenamine.HCl (6.28 g, 20 mmol) and tetrabutylammonium chloride (6.67g, 24 mmol)was dissolved in DMF(30-40 mL) which was degassed for 10 min, followed by the addition of methyl 2-(benzyloxycarbonyl)acrylate (5.65 g, 24 mmol ) and Pd(OAc)2 (0.674 g, 3 mmol), and triethylamine (8.0 mL, 57 mmol) under N2. The mixture was heated at 70° C. for 2.5 hours (the reaction was monitored by LC-MS and TLC, ethyl acetate/hexanes=1:1, Rf=0.24). All volatiles were removed, and the residue was dissolved in CHCl3, which was washed with brine twice, and the organic layer was dried over MgSO4. After filtration, solvents were removed in vacuo and the residue was subjected to flash chromatography using EtOAc/hexanes (1:4, 1:2, 1:1) as eluent to give the title compound as an orange solid 6.87g (71%, yield). All of these solids were refluxed in ethyl acetate (125 mL) and the resulting dark brown solution was filtered. The filtrate was cooled down to r.t. and stored in refrigerator (4° C.) for 2 hrs, then filtered to afford the title compound in a very pure form as an orange solid (5.26 g, recovery yield 62%). 1HNMR (CDCl3, 500 MHz) δ 8.23 (s, 1H), 7.47 (s, 1H), 7.33 (br s, 5H), 7.28 (s, 1H), 6.36 (v br s, 3H), 5.12 (s, 2H), 3.82 (s, 3H), 2.14 (s, 3H); Mass Spec. 386.14 (MH+), Calc. for C19H19N3O6 385.13.
