Phosphorus oxychloride → 4-chloro-5H,6H,7H-cyclopenta[d]pyrimidine

To a solution of 6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-ol (9.87 g, 72.5 mmol) in DCE (200 ml) was added DIEA (15 mL, 86.1 mmol). The mixture was stirred at room temperature for 30 minutes and then added POCl3 (15 mL, 163.9 mmol) was added slowly. The mixture was stirred at room temperature for 1 hour and then refluxed for 12 hour. After cooling, the solvent was removed and the residue was dissolved in CHCl3 (200 ml). The mixture was basified by adding ice-cooled concentrated aqueous ammonia (15 mL). The organic phase was separated. The aqueous phase was washed with CHCl3 (3×100 mL). The organic phase was combined, dried and concentrated. The residue was subject to chromatography on silica gel, eluted by Hexanes/ethyl acetate (4:1) to afford 4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidine (5.7 g, 51%). 1H NMR (CDCl3, 400 MHz) δ 8.76 (s, 1H), 3.12-3.01 (m, 4H), 2.23-2.14 (m, 2H).

1. stirringThe mixture was stirred at room temperature for 1 hour
2. temperaturerefluxed for 12 hour
3. temperatureAfter cooling
4. customthe solvent was removed
5. dissolutionthe residue was dissolved in CHCl3 (200 ml)
6. additionby adding ice-
7. temperaturecooled concentrated aqueous ammonia (15 mL)
8. customThe organic phase was separated
9. washThe aqueous phase was washed with CHCl3 (3×100 mL)
10. customdried
11. concentrationconcentrated
12. washeluted by Hexanes/ethyl acetate (4:1)

ORD record

ord-3490e8a3738f490a90874ed56435d2fc

Source dataset

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09359340B2