Aniline → 4,4-Dimethyl-3,4-dihydroquinolin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

Aniline (7.26 g, 45.2 mmol) and 3-methylbut-2-enoyl chloride (53.2 g, 45.2 mmol) were heated in chloroform at reflux for 2 h. After cooling, the mixture was filtered. The filtrate was concentrated to dryness and dried under vacuum. The crude 3-methyl-but-2-enoic acid phenylamide (ca. 10 g) was dissolved in toluene (50 mL). This toluene solution was added to the stirred AlCl3 powder (27 g) portion-wise. After addition, the resulting dark brown solution was heated at 80° C. for 2.5 h. The warm slurry was poured carefully to stirred crashed ice. The resulting mixture was extracted with EtOAc (3×), washed with sat'd NaHCO3, H2O, brine, and dried over MgSO4. The residue was purified by silica gel flash chromatography (CH2Cl2, then EtOAc) to give 2.2 g of pure 1a and about 4-5 g of less pure portion 1a. LC-MS ESI 176 (M+H).

Provenance & Evidence