3,4-dihydro-2H-pyran → Purine

In a 100 ml three-mouth bottle, 2,6-dichloropurine (10 g), ethyl acetate (50 ml), pyridinium salt of paratoluenesulfonic acid (0.2 g) are mixed. The above mixture is stirred and heated to a temperature of 35° C., 2,3-dihydropyrane (12 ml) is added thereto within 5 min. The reaction mixture is reacted at 50˜60° C. for 3 h. The completion of reaction is checked with TCL analysis. Methylamine hydrochloride (4.6 g) is added to the bottle, and then triethylamine (21 ml) is added thereto at the temperature within 30 min, and the above mixture is reacted at the temperature for 1 h. The completion of reaction is checked with TCL analysis. The reaction mixture is cooled to room temperature. After filtration, a filter cake is completely washed with ethyl acetate, and a filtrate is washed with water for 3 times and delaminated. Organic layer is concentrated till large amounts of solid is separated out. After filtration, a filter cake is washed with ethyl acetate for 3 times and then dried in vacuum at 50° C. for 5 h to obtain solid purin (11.0 g). The yield is about 77.7%.

1. additionis added
2. customThe reaction mixture is reacted at 50˜60° C. for 3 h
3. customThe completion of reaction
4. waitat the temperature within 30 min
5. customthe above mixture is reacted at the temperature for 1 h
6. customThe completion of reaction
7. filtrationAfter filtration
8. washa filter cake is completely washed with ethyl acetate
9. washa filtrate is washed with water for 3 times
10. concentrationOrganic layer is concentrated till large amounts of solid
11. customis separated out
12. filtrationAfter filtration
13. washa filter cake is washed with ethyl acetate for 3 times
14. customdried in vacuum at 50° C. for 5 h

ORD record

ord-b761780df4b144f4b8062109c8915042

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08580763B2