Piperazine → 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 above mixture is reacted at 50˜60° C. for 3 h. The completion of reaction is checked with TCL analysis. Triethylamine (8 ml) and piperazine (7.3 ml) are added to the bottle within 20 min, 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 amount 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 (12.4 g). The yield is about 72.7%.

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

ORD record

ord-66d33d6f9cf04f748d9e8f2e1478a2c0

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08580763B2