反应详情

A mixture of acetic anhydride (2.1 g, 20 mmol), acetaldehyde (4.4 g, 100 mmol), triethylamine (2.0 g, 20 mmol) and 3-(3,5-dimethyl-1H-pyrrol-2-ylmethylidene)-1,3-dihydro-indol-2-one (2.38 g, 10 mmol) in DMF (30 mL) was stirred at room temperature for 3 days. The solvents were removed and the residual oil was chromatographed on silica gel to give, as the first product eluted from the column, 2.5 g of product, which was crystallized from ether to give 2.1 g of the title compound, mp 107–110° C. HPLC Rt 6.78 min. 1H NMR (CDCl3) δ 1.81 (d, 3H), 2.09 (s, 3H), 2.33 (s, 3H), 2.38 (s, 3H), 5.98 (s, 2H), 7.00–7.20 (m, 3H), 7.25 (dd, 1H), 7.39 (s, 1H), 7.51 (dd, 1H) and 13.0 (br s, 1H). Anal. Calcd for C19H20N2O3: C, 70.35; H, 6.21; N, 8.64. Found: C, 70.33; H, 6.18; N, 8.60.

1. customThe solvents were removed
2. customthe residual oil was chromatographed on silica gel
3. customto give, as the first product
4. washeluted from the column, 2.5 g of product, which
5. customwas crystallized from ether