5-Bromoindole → HCID 15326267, compound

Participants

Reaction Steps

A solution of 5-bromoindole (4.00 g, 20.40 mmol) and N-methylmaleimide (5.00 g, 45.00 mmol, 2.2 eq) in glacial acetic acid (50 mL) was heated at reflux under nitrogen for 120 hours. The resulting reaction mixture was evaporated under reduced pressure, and the residue was stirred vigorously in a solution of ether/methylene chloride (9:1, 200 mL) for 2 hours. Undissolved solid was filtered to afford the title compound (4.34 g, 14.13 mmol, 69%) as a pale yellow solid: mp, 196.0-197.0° C.; TLC Rf =0.3 in diethyl ether; 1H NMR (CDCl3) δ8.35 (br m, NH), 7.56 (d, J=1.5 Hz, 1H), 7.29 (dd, J=1.7 and 8.6 Hz, 1H0, 7.22 (d, J=8.7 Hz, 1H), 7.08 (br s, 1H), 4.26 (dd, J=5.1 and 9.4 Hz, 1H), 3.28 (dd, J=9.4 and 18.3 Hz, 1H), 3.11 (s, 3H), 2.87 (dd, J=5.1 and 18.3 Hz, 1H); FAB LRMS (m/z, relative intensity, NH4 +as ionization source) 326 ([M(with 81Br)NH4 ]+, 100), 324 ([M(with 79Br)NH4 ]+, 96), 309 ([M(with 81Br)H]+, 21), 307 ([M(with 79Br)H]+, 20). Anal. calcd for C13H11BrN2O2 : C, 50.84; H, 3.61; N, 9.12. Found: C, 50.67; H, 3.43; N, 9.00.

Provenance & Evidence