Sodium Hydroxide → 3-(2-Fluoropropan-2-yl)-1,2-oxazol-5-amine

To a stirred solution of 4-fluoro-4-methyl-3-oxopentanenitrile from Step 1 (12.9 g, 0.1 mol) and sodium hydroxide (8.20 g, 0.11 mol) in 1:1 water/EtOH (184 mL) was added hydroxylamine sulfate (17.23 g, 0.11 mol). The mixture was adjusted to pH 7.5 with 1N NaOH, then heated at 80° C. for 15 h. After cooling to rt, the mixture was concentrated to dryness under reduced pressure. The resulting solid was partitioned between water and dichloromethane, and the separated organic layer was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with 0-10% EtOAc in petroleum ether to afford 3-(2-fluoropropan-2-yl)isoxazol-5-amine as a yellow solid (5 g, 35%). LC-MS (ESI) m/z 145 (M+H)+.

1. temperatureAfter cooling to rt
2. concentrationthe mixture was concentrated to dryness under reduced pressure
3. customThe resulting solid was partitioned between water and dichloromethane
4. washthe separated organic layer was washed with brine
5. dry with materialdried over MgSO4
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by silica gel chromatography
8. washeluting with 0-10% EtOAc in petroleum ether

ORD record

ord-a3e491f1aeaa486a88f9e7f5e70678c0

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09296722B2