反应详情

3,4-Dihydro-7-methyl-6-(1-oxopropyl)-3-oxo-1,4(2H)-benzoxazine (23.7 g) was added to a mixture of 13 g of dimethylamine hydrochloride and 15 ml of 37% aqueous formaldehyde solution in 68 ml of acetic anhydride. After heating on a steam bath for three hours, 50 ml of acetone was added and heating was continued for 15 minutes. The solvents were removed by evaporation at reduced pressure and the residue was dissolved in 1N HCl and washed with ethyl acetate. The aqueous layer was basified with sodium hydroxide and the resultant crystals were collected by filtration. This product was dissolved in 500 ml of acetone and 10 ml of iodomethane were added. After heating at reflux overnight, the solid which formed was collected by filtration and washed with acetone. The product was dissolved in 400 ml of 50% aqueous methanol and 18 g of potassium cyanide in 200 ml of water was added. After stirring overnight at room temperature, the solid was collected and washed with water. The damp filter cake was suspended in 500 ml of 6N HCl and heated at reflux for 1.5 hours. Upon cooling a white precipitate formed which was collected by filtration and washed with water to give 19.4 g (81% yield) of the title compound, mp 169.5°-172° C.

1. temperatureAfter heating on a steam bath for three hours
2. temperatureheating
3. customThe solvents were removed by evaporation at reduced pressure
4. dissolutionthe residue was dissolved in 1N HCl
5. washwashed with ethyl acetate
6. filtrationthe resultant crystals were collected by filtration
7. dissolutionThis product was dissolved in 500 ml of acetone
8. addition10 ml of iodomethane were added
9. temperatureAfter heating
10. temperatureat reflux overnight
11. customthe solid which formed
12. filtrationwas collected by filtration
13. washwashed with acetone
14. dissolutionThe product was dissolved in 400 ml of 50% aqueous methanol
15. addition18 g of potassium cyanide in 200 ml of water was added
16. customthe solid was collected
17. washwashed with water
18. temperatureheated
19. temperatureat reflux for 1.5 hours
20. temperatureUpon cooling a white precipitate
21. customformed which
22. filtrationwas collected by filtration
23. washwashed with water