The general procedure for the synthesis of 7-methoxyquinazolin-4(1H)-one from formamidine acetate and 2-amino-4-methoxybenzoic acid was as follows:
1. 2-Amino-4-methoxybenzoic acid (4.85 g, 28.9 mmol) and formamidine acetate (18.49 g, 177.8 mmol) were mixed in 100 mL of 2-methoxyethanol.
2. The reaction mixture was heated to reflux and stirred under these conditions for 12 hours.
3. After completion of the reaction, the mixture was cooled to 25 °C. The reaction was carried out with 0.01 M
4. Dilute the cooled reaction mixture with 0.01 M aqueous ammonia solution (100 mL).
5. Continue stirring at 25 °C for 30 min.
6. Collect the light brown solid product formed by filtration.
7. Wash the solid product with 0.01 M aqueous ammonia solution. 8.
8. The final product 7-methoxyquinazolin-4(1H)-one was obtained by high vacuum drying in a yield of 11.5 g (73% yield).
Product characterization data:
NMR (δ, ppm): 12.10 (s, br, 1H), 8.05 (m, 2H), 7.10 (m, 2H), 3.90 (s, 3H); m/z 167.
