Sodium Carbonate → (R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine 1-oxide

To a solution of (R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta [d]pyrimidine (2.5 g, 14.8 mmol) in CHCl3 (60 mL) was added MCPBA (8.30 g, 37.0 mmol) in three portions. The mixture was stirred at room temperature for 2 days. The mixture was cooled to 0° C. and to this was added dropwise Na2S2O3 (10 g) in water (60 mL), followed by Na2CO3 (6 g) in water (20 mL). The reaction mixture was stirred for 20 minutes. The aqueous phase was extracted with CHCl3 (2×200 mL), and the combined organic phases were concentrated at low temperature (<25° C.). The residue was purified by silica gel chromatography, eluting with ethyl acetate-DCM/MeOH (20:1) to give (R)-4-chloro-5-methyl-6,7-dihydro-5H-cyclopenta [d]pyrimidine-oxide (1.45 g, 53%). 1H NMR (CDCl3, 400 MHz) δ 8.66 (s, 1H), 3.50 (m, 1H), 3.20 (m, 2H), 2.44 (m, 1H), 1.90 (m, 1H), 1.37 (d, J=7.2 Hz, 3H).

1. temperatureThe mixture was cooled to 0° C.
2. stirringThe reaction mixture was stirred for 20 minutes
3. extractionThe aqueous phase was extracted with CHCl3 (2×200 mL)
4. concentrationthe combined organic phases were concentrated at low temperature (<25° C.)
5. customThe residue was purified by silica gel chromatography
6. washeluting with ethyl acetate-DCM/MeOH (20:1)

ORD record

ord-13e85696022f48a8b6343666c4bf3725

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08063050B2