Phosphorus oxychloride → (R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine

A mixture of (R)-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-ol (5.8 g, 38.62 mmol) in POCl3 (20 mL) was refluxed for 5 minutes. Excess POCl3 was removed under vacuum, and the residue was dissolved in DCM (50 mL). The mixture was then added to saturated NaHCO3 (200 mL). The aqueous phase was extracted with DCM (3×100 mL), and the combined organic phases were dried and concentrated. The residue was purified by silica gel chromatography, eluting with ethyl acetate to give (R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine (3.18 g, 49%). 1H NMR (CDCl3, 400 MHz) δ 8.81 (s, 1H), 3.47 (m, 1H), 3.20 (m, 1H), 3.05 (m, 1H), 2.41 (m, 1H), 1.86 (m, 3H), 1.47 (m, 3H).

1. temperaturewas refluxed for 5 minutes
2. customExcess POCl3 was removed under vacuum
3. dissolutionthe residue was dissolved in DCM (50 mL)
4. additionThe mixture was then added to saturated NaHCO3 (200 mL)
5. extractionThe aqueous phase was extracted with DCM (3×100 mL)
6. customthe combined organic phases were dried
7. concentrationconcentrated
8. customThe residue was purified by silica gel chromatography
9. washeluting with ethyl acetate

ORD record

ord-3da9d5ba0bdb47b5ae2b967c10896e0e

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08846683B2