2-Aminopyridine → 3-(2-Chloroethyl)-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one

40 g of 2-aminopyridine and 75 ml of 3-acetyl-4,5-dihydro-2(3H)-furanone were added to 1.0 L of toluene, and then 200 ml of phosphorus oxychloride was added thereto dropwise over 1 hour. The resulting mixture was slowly heated and refluxed for 5 hours. The reaction mixture was concentrated under a reduced pressure and the residue was poured to a mixture of ice and ammonia water. The resulting solid was extracted with 1.0L of dichloromethane, dried and filtered. The filtrate was concentrated under a reduced pressure to remove dichloromethane and 500 ml of isopropanol was added to the residue. The resulting crystal was filtered, washed and dried to obtain 48.1 g of the title compound as a off-white crystal (yield: 52%).

1. temperatureThe resulting mixture was slowly heated
2. temperaturerefluxed for 5 hours
3. concentrationThe reaction mixture was concentrated under a reduced pressure
4. additionthe residue was poured to a mixture of ice and ammonia water
5. extractionThe resulting solid was extracted with 1.0L of dichloromethane
6. customdried
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under a reduced pressure
9. customto remove dichloromethane and 500 ml of isopropanol
10. additionwas added to the residue
11. filtrationThe resulting crystal was filtered
12. washwashed
13. customdried

ORD record

ord-b47b94b644e949218b445450f4c887b3

Source dataset

uspto-grants-2007_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07202360B2