Borane → HCID 54321631, compound

Temperature

0 °C

Borane (in THF, 1M, 10.35 mL, 10.5 mmol) was added dropwise into a mixture of (R)-2-methyl-CBS-oxazaborolidine monohydrate (0.38 g, 1.31) mmol and tetrahydrofuran (15 mL) under a nitrogen atmosphare at ambient temperature. The mixture was stirred for 10 minutes and then 2-bromo-1-[2-(trifluoromethyl)-1,3-thiazole-4-yl]ethanone (which was obtained in Example 102) (3.6 g, 13.13 mmol) in tetrahydrofuran (20 mL) was added dropwise over 10 minutes. The new mixture was stirred at room temperature for 4 hours. The reaction mixture was cooled to 0° C. and quenched with a hydrogen chloride/ethyl ether solution (1M, 1.0 mL). After stirring at 0° C. for 30 minutes, H2O (20 mL) was added dropwise and the mixture was extracted with ethyl ether. The organic layer was washed with aqueous ammonium chloride and dried over MgSO4. Evaporation and purification by flash chromatography (hexanes/dichloromethane/ethanol 1/1/0.01) gave a clear oil (2,4 g, 66% yield); MS (ES) m/z: 334/336 (M+acetic acid−H)−; 1H NMR (400 MHz, CDCl3) δ 2.94 (m, 1H), 3.74 (m, 1H), 3.94 (m, 1H), 5.16 (m, 1H), 7.62 (s, 1H).

1. stirringThe new mixture was stirred at room temperature for 4 hours
2. customquenched with a hydrogen chloride/ethyl ether solution (1M, 1.0 mL)
3. stirringAfter stirring at 0° C. for 30 minutes
4. additionH2O (20 mL) was added dropwise
5. extractionthe mixture was extracted with ethyl ether
6. washThe organic layer was washed with aqueous ammonium chloride
7. dry with materialdried over MgSO4
8. customEvaporation and purification by flash chromatography (hexanes/dichloromethane/ethanol 1/1/0.01)

ORD record

ord-3d69fb8d3c50419aa8227bb884c357cf

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06525202B2