2-(Benzenesulfonyl)-3-phenyloxaziridine → Methyl 2-(2-bromo-7-chloro-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate

Temperature

-78 °C

To a stirred solution of KHMDS (0.5 M in toluene, 2.83 mL, 1.413 mmol) in THF (6 mL) at −78° C. was added a solution of methyl 2-(2-bromo-7-chloro-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)acetate (300 mg, 0.942 mmol) in THF (6 mL) dropwise over 20 min. The mixture was stirred at −78° C. for 30 min. A solution of 3-phenyl-2-(phenylsulfonyl)-1,2-oxaziridine (369 mg, 1.413 mmol) in THF (6 mL) was added over 15 min and the reaction mixture was stirred for additional 60 min at −78° C. The reaction mixture was quenched with saturated NH4Cl aqueous solution (4 mL). The reaction mixture was allowed to warm to room temperature and then diluted with ethyl acetate (100 mL). The organic phase was washed with water and brine and dried with sodium sulfate. The solvent was evaporated. Purification by silica gel chromatography provided the title compound (85 mg, 27%). 1H NMR (400 MHz, CHLOROFORM-d) δ 2.63 (3 H, s), 3.84 (3 H, s), 5.74 (1 H, s), 6.71 (1 H, s).

1. stirringthe reaction mixture was stirred for additional 60 min at −78° C
2. customThe reaction mixture was quenched with saturated NH4Cl aqueous solution (4 mL)
3. temperatureto warm to room temperature
4. additiondiluted with ethyl acetate (100 mL)
5. washThe organic phase was washed with water and brine
6. dry with materialdried with sodium sulfate
7. customThe solvent was evaporated
8. customPurification by silica gel chromatography

ORD record

ord-656c98dca39a41a5ba5ac64edd34d468

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09034882B2