Acetic Acid → Methyl-(2E)-2-cyano-3-(2,3-dihydro-1-benzofuran-5-yl)-2-butenoate

Participants

Reaction Steps

To a stirred solution of 5-acetyl-2,3-dihydrobenzo[b]furan (Aldrich) (1 g, 6.17 mmol) in toluene (60 ml) was added methyl cyanoacetate (0.60 ml, 6.78 mmol), benzylamine (0.07 ml, 0.61 mmol) and acetic acid (0.3 ml, 5.3 mmol) and the whole refluxed in a Dean-Stark apparatus for 16 h. The reaction mixture was cooled, washed with 2N HCl (30 ml), NaHCO3 (30 ml), brine (30 ml), dried (MgSO4) and evaporated to a yellow residue. This residue was purified by column chromatography using 15-20% EtOAc in pentane as eluant to provide the title product (902 mg, 60%); 1HNMR (400 MHz, CDCl3) δ: 2.65 (s, 3H), 3.25 (t, 2H), 3.9 (s, 3H), 4.6 (t, 2H), 6.8 (d, 1H), 7.25 (d, 1H), 7.8 (s, 1H); LRMS: M+NH4+, 261. (ES+).

Provenance & Evidence