Trimethyl phosphonoacetate → 4-methoxy-2-methyl-1H-pyrrolo[2,3-b]pyridine

Participants

Reaction Steps

3-(1-Benzyl-5-methyl-1H-pyrrol-2-yl)-acrylic acid methyl ester, 5: Sodium (14.45 g, 628 mmol) was added in portions to a dry methanol (420 mL). To the fresh formed sodium methoxide solution was added dropwise the solution of trimethyl phosphonoacetate (50 mL, 302 mmol) in tetrahydrofuran (105 mL) at room temperature. After addition the mixture was stirred for additional 60 min at room temperature. Then to the reaction mixture was added dropwise the solution of 1-benzyl-5-methyl-1H-pyrrole-2-carbaldehyde, 4 (30.8 g, 154 mmol) in tetrahydrofuran (630 mL) at room temperature. The reaction mixture was stirred for 2 h at room temperature. The mixture was concentrated and redissolved in ethyl acetate (1 L). The mixture was washed with 1 M HCl solution, then saturated NaHCO3, H2O. The organic solution were dried over MgSO4 and then filtered, concentrated to afford the crude product, 3-(1-benzyl-5-methyl-1H-pyrrol-2-yl)-acrylic acid methyl ester, 5 as a light yellow solid. Yield: 40 g

Provenance & Evidence