Isatin → 1-Allylisatin

Participants

Reaction Conditions

Reaction Steps

A 500 mL flask is charged with isatin (50 g, 339 mmol), allyl chloride (33.8 g, 441 mmol), potassium carbonate (93.9 g, 679 mmol), and DMF (100 mL). The mixture is stirred at 70° C. for 14 hours (complete conversion by TLC), and then diluted with DMF. After filtration over a pad of cellite and removal of the solvent, the product remained as red crystals (68 g) which are used directly in the next step. 1HNMR (CDCl3, 300 MHz) δ 4.34 (dtr, 1H, 3 J=5.3 Hz, 4J=1.8 Hz, NCH2CHC═CH2); 5.27 (dm, 1H, 3J=10.3 Hz, NCH2CHC═CHcis); 5.30 (dm, 1H, 3J=17.0 Hz, NCH2CHC═CHtrans); 5.82 (ddtr, NCH2CHC═CH2); 6.87 (d, 1H, 3J=7.9 Hz, H-7); 7.09 (br tr, 1H, 3J=7.3 Hz, H-5); 7.55 (dtr, 1H, 3 J=8 Hz, H-6); 7.57 (d m, 1H, 3J=7.3 Hz, H-4). 13C-NMR (CDCl3, 75 MHz) δ 42.82 (NCH2); 111.11 (C-7); 117.77 (C-9); 118.80 (CH═CH2); 123.96 (C-5); 125.50 (C-4); 130.51 (CH═CH2); 138.48 (C-6); 150.96 (C-8); 158.02 (C-2); 183.29 (C-3).

Provenance & Evidence