Acetic Acid → 1-(4-Bromophenyl)-2,5-Dimethyl-1H-Pyrrole

Reaction equation

[Br:1][C:2]1[CH:8]=[CH:7][C:5]([NH2:6])=[CH:4][CH:3]=1.[CH3:9][C:10](=O)[CH2:11][CH2:12][C:13](=O)[CH3:14].C(O)(=O)C>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:8]=[CH:7][C:5]([N:6]2[C:13]([CH3:14])=[CH:12][CH:11]=[C:10]2[CH3:9])=[CH:4][CH:3]=1

Participants

Procedure

4-Bromoaniline (56.0 g., 0.33 Mol.), 2,5-hexanedione (37.6 g., 0.33 Mol), and acetic acid (5 mL) were placed into Toluene (500 mL) and heated under reflux for 8 hours employing a dean stark trap to remove the water from the reaction. The reaction was cooled to room temperature and concentrated under reduced vacuum. The resulting oil was taken into ethyl acetate, washed one time each with 2N hydrochloric acid, 2N NaOH, and H2O, dried over Na2SO4, and concentrated under reduced vacuum to yield a brown solid. The material was purified by silica gel flash chromatography eluting with hexanes. Concentration of the appropriate fractions yielded 55.0 gm. of a light yellow solid. (68%) The NMR spectrum was consistent with the proposed title structure. Field Desorption Mass Spectrum: M+ 249 m.p. 71°-73° C.