Ethanol → 2-(2-ethoxyphenyl)-4-(3H)-quinazolone

Participants

Reaction Steps

An equimolar mixture of anthranilamide (136 mg, 1.0 mmole) and 2-ethoxybenzaldehyde (166 mg, 1.0 mmole) is suspended in methanol (30 mL) and heated to reflux for 3 hours. After cooling, the Schiff's base is isolated by vacuum filtration, suspended in ethanol (50 mL) containing p-toluenesulfonic acid (33 mg, 0.17 mmole), and heated to reflux for 1 hour. The resulting dihydroquinazolone is treated with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ, 227 mg, 1.0 mmole) and heating is continued as above for 1 hour. After cooling to room temperature, the precipitated solid is filtered and washed with methanol. The product is recrystallized from methanol to yield a colorless solid. 1H-NMR (CDCl3)δ:8.54 (d, 1H); 8.30 (d, 1H); 7.77 (m,2H); 7.51-7.43 (m,2H); 7.15 (t, 1H); 7.05 (d,1H); 4.30 (q,2H,--CH2CH3); 1.60(t,3H,--CH2CH3).

Provenance & Evidence