Water → 4-(3-bromobenzyl)-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one

To a solution of 2.30 g (20 mmol) of 5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one in 20 ml acetonitrile was added 2.90 g (21 mmol) of potassium carbonate. A solution of 5.00 g (20 mmol) of 3-bromobenzylbromide in 20 ml of dry acetonitrile was added dropwise thereto at 55° C. After the mixture was stirred at the same temperature for additional 6 hours, water was added to the reaction mixture and the mixture was extracted with ethyl acetate. The organic layer was washed with water, dried and concentrated. To the resultant solid residue (5.2 g) was added a mixture of equal amounts of tert-butyl methyl ether and n-hexane and the solid was washed, ice-cooled, collected by filtration and concentrated. Further, to the resultant solid residue was added tert-butyl methyl ether and the solid was washed, cooled, collected by filtration and dried to obtain 1.70 g (5.98 mmol) of 4-(3-bromobenzyl)-5-methoxy-2,4-dihydro-3H-1,2,4-triazol-3-one as white powder.

1. customat 55° C
2. extractionthe mixture was extracted with ethyl acetate
3. washThe organic layer was washed with water
4. customdried
5. concentrationconcentrated
6. additionTo the resultant solid residue (5.2 g) was added
7. additiona mixture of equal amounts of tert-butyl methyl ether and n-hexane
8. washthe solid was washed
9. temperatureice-cooled
10. filtrationcollected by filtration
11. concentrationconcentrated
12. additionFurther, to the resultant solid residue was added tert-butyl methyl ether
13. washthe solid was washed
14. temperaturecooled
15. filtrationcollected by filtration
16. customdried

ORD record

ord-f8236be7116c468bbe93edc59af9d5e2

Source dataset

uspto-grants-2002_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06489487B1