Acetic Acid → 4-Bromo-1,2-diethyl-1,2-dihydro-3,6-pyridazinedione

Participants

Reaction Conditions

Reaction Steps

A mixture of monobromomaleic anhydride (177 mg, 1.0 mmol) and N,N-diethylhydrazine (88 mg, 1.0 mmol) in glacial AcOH (3 mL) was heated at 130° C. for 16 h. The solvent was removed in vacuo and the crude residue purified by column chromatography (neat CH2Cl2-5% MeOH/CH2Cl2) to give 4-bromo-1,2-diethyl-1,2-dihydro-pyridazine-3,6-dione as a yellow solid (159 mg, 0.64 mmol, 64%): 1H NMR (600 MHz, CDCl3) δ 7.31 (s, 1H), 4.14 (q, J=7.0 Hz, 2H), 4.07 (q, J=7.0 Hz, 2H), 1.26 (t, J=7.0 Hz, 3H), 1.22 (t, J=7.0 Hz, 3H); 13C NMR (150 MHz, CDCl3) δ 156.2 (s), 154.3 (s), 136.0 (d), 133.7 (s), 41.9 (t), 40.7 (t), 13.3 (q), 13.3 (q); IR (solid) 3058, 2979, 2938, 1631, 1595 cm−1; LRMS (CI) 249 (100, [M81Br+H]+), 247 (100, [M79Br+H]+); HRMS (CI) calcd for C8H12BrN2O2 [M+H]+ 249.0082, observed 249.0086.

Provenance & Evidence